Binder composition and its use

Abstract

A method for producing a thermoplastic binder from virgin and / or waste plastics in an extruder and the use of the binder to produce thermoplastic composite products, such as composite boards, is described. A portion of the thermoplastic can be reacted with a coupling agent to produce a functionalized thermoplastic and / or dispersed in water with agitation to produce a thermoplastic dispersion.

Description

[Technical Field]

[0001] The present invention relates to a method for producing a binder and its use in the production of plastic composite products. [Background technology]

[0002] Plastic is a widely used material in both household and industrial products. Many countries are working to dispose of or utilize waste plastics in an economical and safe manner. While it is known to recycle plastics into other products, energy and resources are required to clean the plastics, reduce their original form to the desired particle size, and then reuse them in recycled products.

[0003] Binders are used in a variety of industrial and consumer applications. One such binder is urea-formaldehyde (UF), so named because of its general synthetic route and overall structure. UF products are thermosetting resins or polymers used as binders / adhesives. However, UF binders have drawbacks, including emissions of volatile organic compounds that can have adverse health effects, an energy-intensive manufacturing process, and associated regulatory hurdles. Therefore, alternative binders are needed. Additionally, UF adhesives bond materials by undergoing a reversible condensation reaction, especially under certain environmental conditions. In humid or wet environments, UF adhesives can undergo hydrolysis, meaning the adhesive can decompose back into its original components. This hydrolysis results in a decrease in bond strength and durability, making UF adhesives unsuitable for use in moisture-exposed environments and potentially compromising the structural integrity of the bonded product.

[0004] Plastic waste poses a variety of environmental, economic, and societal challenges. These include environmental impacts due to its lack of biodegradability, such as marine pollution harming marine life, chemical leaching of toxic products and by-products into the food chain, microplastic pollution, and air pollution where plastics are burned for energy. Therefore, there is a need to reduce, reuse, and recycle plastic waste to extend its useful life and reduce its negative impact on the environment.

[0005] It is an object of the present invention to provide a method for making binders and optionally to provide methods for using them, or at least to provide the public with a useful choice. Summary of the Invention [Means for solving the problem]

[0006] According to a first aspect, providing a source of thermoplastic; introducing a thermoplastic into an inlet end of one or more extruders; melting the thermoplastic sufficiently in one or more extruders to form a melt zone; 1. A method for producing a thermoplastic binder, comprising: a) reacting at least a portion of a thermoplastic with a coupling agent to form a functionalized thermoplastic; or b) dispersing a thermoplastic in water with agitation to form an emulsification zone and produce a thermoplastic dispersion; or c) performing (a) followed by (b) to produce a dispersion of a functionalized thermoplastic; A method is described that includes:

[0007] According to a first aspect, providing a source of thermoplastic; introducing a thermoplastic into an inlet end of one or more extruders; melting the thermoplastic sufficiently in one or more extruders to form a melt zone; A method for producing a thermoplastic binder, comprising: a) reacting at least a portion of a thermoplastic with a coupling agent to form a functionalized thermoplastic; or b) dispersing a thermoplastic in water with agitation to form an emulsification zone and produce a thermoplastic dispersion; or c) performing (a) followed by (b) to produce a dispersion of a functionalized thermoplastic; A method is described that includes:

[0008] According to a first aspect, providing a source of thermoplastic; introducing a thermoplastic into an inlet end of one or more extruders; melting the thermoplastic sufficiently in one or more extruders to form a melt zone; 1. A method for producing a thermoplastic binder, comprising: a) reacting at least a portion of a thermoplastic with a coupling agent to form a functionalized thermoplastic; or b) dispersing a thermoplastic in water with agitation to form an emulsification zone and produce a thermoplastic dispersion; or c) performing (a) followed by (b) to produce a dispersion of a functionalized thermoplastic; A method is described which consists essentially of:

[0009] According to a first aspect, providing a source of thermoplastic; introducing a thermoplastic into an inlet end of one or more extruders; melting the thermoplastic sufficiently in one or more extruders to form a melt zone; 1. A method for producing a thermoplastic binder, comprising: a) reacting at least a portion of a thermoplastic with a coupling agent to form a functionalized thermoplastic; or b) dispersing a thermoplastic in water with agitation to form an emulsification zone and produce a thermoplastic dispersion; or c) performing (a) followed by (b) to produce a dispersion of a functionalized thermoplastic; Including, i) the ratio of high melting point thermoplastic to low melting point thermoplastic in the thermoplastic source is 1:4 to 4:1; ii) the coupling agent, if present, is present at 3% to 10% by weight of the thermoplastic; or iii) Moisture content?? iv) (i) and (ii) A method is described.

[0010] According to another aspect, there is provided a method for producing a binder, comprising the steps of: As a functionalized thermoplastic that has been processed by sufficiently melting the thermoplastic in an extruder to form an extruder melt zone and reacting the thermoplastic with a coupling agent in the extruder; or as a thermoplastic dispersion processed by sufficiently melting a thermoplastic in an extruder to form an extruder melt zone and then dispersing the thermoplastic in water with agitation in an extruder emulsification zone; or · The thermoplastic is sufficiently melted in the extruder to form an extruder melt zone; reacting a thermoplastic with a coupling agent in an extruder to form a functionalized thermoplastic; The functionalized thermoplastic is then dispersed in water with stirring in the emulsification zone of the extruder. as a dispersion of functionalized thermoplastics treated by Obtaining treated thermoplastics; and thereafter adding a crosslinking agent to the treated thermoplastic to form a binder; A method is described that includes:

[0011] According to another aspect, there is provided a method for producing a thermoplastic composite product, the method comprising: as functionalized thermoplastics, or as thermoplastic dispersions, or As dispersions of functionalized thermoplastics, obtaining a binder; the binder is formed by introducing a thermoplastic into the inlet end of one or more extruders, sufficiently melting the thermoplastic in the one or more extruders, mixing the binder with a substrate in fibrous form to form a composite mixture, and applying heat and pressure to the composite mixture in a press or mold to form a thermoplastic composite product; A method is described.

[0012] According to another aspect, providing a source of thermoplastic; introducing a thermoplastic into an inlet end of one or more extruders; melting the thermoplastic sufficiently in one or more extruders to form a melt zone; 1. A method for producing a thermoplastic binder, comprising: a) reacting at least a portion of a thermoplastic with a coupling agent to form a functionalized thermoplastic; or b) dispersing a thermoplastic in water with agitation to form an emulsification zone and produce a thermoplastic dispersion; or c) performing (a) followed by (b) to produce a dispersion of a functionalized thermoplastic; thereafter adding a crosslinking agent to the functionalized thermoplastic or thermoplastic dispersion by adding the crosslinking agent to the extruder or to the extruded functionalized thermoplastic or thermoplastic dispersion to produce a thermoplastic binder; A method is described that includes:

[0013] According to another aspect, providing a source of thermoplastic; introducing a thermoplastic into an inlet end of one or more extruders; melting the thermoplastic sufficiently in one or more extruders to form a melt zone; 1. A method for producing a thermoplastic composite product, comprising: a) reacting at least a portion of a thermoplastic with a coupling agent to form a functionalized thermoplastic; or b) dispersing a thermoplastic in water with stirring to form a thermoplastic dispersion; or c) performing (a) followed by (b) to produce a dispersion of a functionalized thermoplastic; and mixing the extruded functionalized thermoplastic or thermoplastic dispersion with a substrate in fiber form to form a composite mixture, and applying heat and pressure to the composite mixture in a press or mold to form a thermoplastic composite article; A method is described that includes:

[0014] According to another aspect, providing a source of thermoplastic; introducing a thermoplastic into an inlet end of one or more extruders; melting the thermoplastic sufficiently in one or more extruders to form a melt zone; 1. A method for producing a thermoplastic composite product, comprising: a) reacting at least a portion of a thermoplastic with a coupling agent to form a functionalized thermoplastic; or b) dispersing a thermoplastic in water with stirring to form a thermoplastic dispersion; or c) performing (a) followed by (b) to produce a dispersion of a functionalized thermoplastic; and thereafter adding a crosslinking agent to the functionalized thermoplastic or thermoplastic dispersion by adding the crosslinking agent to the extruder or to the extruded functionalized thermoplastic or thermoplastic dispersion to produce a binder; and mixing the binder with a substrate in fibrous form to form a composite mixture and applying heat and pressure to the composite mixture in a press or mold to form a thermoplastic composite product; A method is described that includes:

[0015] According to another aspect, waste thermoplastics and; with lignocellulosic materials; with a crosslinking agent; A composite board comprising: The lignocellulosic material comprises at least 75% of the composite board; A composite board is described.

[0016] According to another aspect, there is provided a thermoplastic dispersion comprising functionalized waste thermoplastic and water, the thermoplastic includes at least one of a high melting point thermoplastic, such as polypropylene, and a low melting point thermoplastic, such as polyethylene; Water is present in the dispersion at approximately 25% to 75%. A thermoplastic dispersion is described.

[0017] In another aspect, there is provided a method for producing a thermoplastic dispersion, the method comprising: feeding the thermoplastic into one or more extruders (which may be modular) to melt the thermoplastic; adding a coupling agent to the extruder to produce a functionalized thermoplastic; adding water and a surfactant to emulsify the functionalized thermoplastic and applying shear forces to produce a dispersion of particulate functionalized thermoplastic; A method is described that includes:

[0018] In a further aspect, there is provided a method for producing a thermoplastic dispersion, comprising the steps of: feeding the thermoplastic into one or more extruders (which may be modular) to melt the thermoplastic; adding a coupling agent to the extruder to produce a functionalized thermoplastic; adding water and a surfactant to emulsify the functionalized thermoplastic and applying shear forces to produce a dispersion of particulate functionalized thermoplastic; adding one or more crosslinking agents to the particulate functionalized thermoplastic dispersion, which preferably bond with the functionalized thermoplastic of the particulate functionalized thermoplastic dispersion; A method is described that includes:

[0019] In a further aspect, there is provided a method for producing a plastic dispersion, comprising the steps of: providing one or more extruders including a housing having an inlet end and an outlet end; introducing a thermoplastic into an inlet end of one or more twin screw extruders and melting the thermoplastic sufficiently within the one or more twin screw extruders to form a melt zone, wherein at least a portion of the thermoplastic is a) a grafted compatibilizer, or b) a reactive hydrogen donor, or c) Both (a) and (b) has reacted or will react with a coupling agent selected from In the case of a single twin-screw extruder process, all of the processed thermoplastic reacts with the coupling agent, or wherein at least 10 wt. % of the thermoplastic is processed through the functionalized extruder process to form a functionalized molten thermoplastic, when the process includes one or more twin screw extruders used simultaneously or sequentially to form a functionalized extruder process with a coupling agent and a non-functionalized extruder process without a coupling agent; intimately mixing the molten functionalized thermoplastic with a first quantity of water and a surfactant under shear, and intimately mixing the molten functionalized thermoplastic with a second quantity of water downstream of the first quantity of water to form an emulsified zone to form a functionalized thermoplastic having an average particle size of less than 0.5 mm, producing a dispersion of the functionalized thermoplastic with water as a continuous phase; and extruding a dispersion comprising functionalized plastic particles having an average particle size of less than 0.5 mm from one outlet end of one or more extruders; A method is described that includes:

[0020] In a further aspect, there is provided a method for producing a plastic dispersion, comprising the steps of: providing one or more extruders including a housing having an inlet end and an outlet end; introducing a thermoplastic into an inlet end of one or more twin screw extruders and melting the thermoplastic sufficiently within the one or more twin screw extruders to form a melt zone, wherein at least a portion of the thermoplastic is a) a grafted compatibilizer, or b) a reactive hydrogen donor, or c) Both (a) and (b) has reacted or will react with a coupling agent selected from In the case of a single twin-screw extruder process, all of the processed thermoplastic reacts with the coupling agent, or wherein at least 10 wt. % of the thermoplastic is processed through the functionalized extruder process to form a functionalized molten thermoplastic, when the process includes one or more twin screw extruders used simultaneously or sequentially to form a functionalized extruder process with a coupling agent and a non-functionalized extruder process without a coupling agent; intimately mixing the molten functionalized thermoplastic with a first quantity of water and a surfactant under shear and intimately mixing with a second quantity of water downstream of the first quantity of water to form an emulsified zone of functionalized thermoplastic particles having an average particle size of less than 0.5 mm to produce a dispersion of the functionalized thermoplastic with water as a continuous phase; adding a crosslinker in liquid form and optional additional water to a dispersion of functionalized thermoplastic in one or more extruders at a temperature insufficient to chemically activate the crosslinker; extruding a dispersion comprising functionalized plastic particles having an average particle size of less than 0.5 mm from one outlet end of one or more extruders; A method is described that includes:

[0021] In a further aspect, there is provided a method for producing a lignocellulosic-thermoplastic composite product, comprising the steps of: providing one or more extruders including a housing having an inlet end and an outlet end; introducing a thermoplastic into an inlet end of one or more twin screw extruders and melting the thermoplastic sufficiently within the one or more twin screw extruders to form a melt zone, wherein at least a portion of the thermoplastic is a) a grafted compatibilizer, or b) a reactive hydrogen donor, or c) Both (a) and (b) has reacted or will react with a coupling agent selected from In the case of a single twin-screw extruder process, all of the processed thermoplastic reacts with the coupling agent, or wherein at least 10 wt. % of the thermoplastic is processed through the functionalized extruder process to form a functionalized molten thermoplastic, when the process includes one or more twin screw extruders used simultaneously or sequentially to form a functionalized extruder process with a coupling agent and a non-functionalized extruder process without a coupling agent; intimately mixing the molten functionalized thermoplastic with a first quantity of water and a surfactant under shear and intimately mixing with a second quantity of water downstream of the first quantity of water to form an emulsified zone of functionalized thermoplastic particles having an average particle size of less than 0.5 mm to produce a dispersion of the functionalized thermoplastic with water as a continuous phase; adding a crosslinker in liquid form and optional additional water to a dispersion of functionalized thermoplastic in one or more extruders at a temperature insufficient to chemically activate the crosslinker; extruding a dispersion comprising functionalized plastic particles having an average particle size of less than 0.5 mm from one outlet end of one or more twin-screw extruders; Optionally, drying the dispersion to a moisture content of 3% by weight to form a binder; and mixing the binder with the lignocellulosic material / fiber to form a composite mixture and applying heat and pressure to the composite mixture in a press to form a lignocellulosic-thermoplastic composite; A method is described that includes:

[0022] In a further aspect, there is provided a method for producing a lignocellulosic-thermoplastic composite product, comprising the steps of: providing one or more extruders including a housing having an inlet end and an outlet end; introducing a thermoplastic into an inlet end of one or more twin screw extruders and sufficiently melting the thermoplastic within the one or more twin screw extruders to form a melt zone; emulsifying the molten functionalized thermoplastic to form an emulsion zone by subjecting the functionalized thermoplastic to water, a surfactant, and sufficient shear to form a functionalized thermoplastic having an average particle size of less than 0.5 mm, producing a dispersion of the functionalized thermoplastic having water as a continuous phase; adding, in one or more extruders, to a dispersion of functionalized thermoplastic, an organic peroxide-based crosslinking agent in liquid form and optional water at a temperature insufficient to chemically activate the crosslinking agent; extruding a dispersion comprising functionalized plastic particles having an average particle size of less than 0.5 mm from one outlet end of one or more extruders; drying the dispersion to a moisture content of 3% by weight to form a binder; and mixing the binder with the cellulose fibers to form a composite mixture and applying heat and pressure to the composite mixture in a press to form a lignocellulose-thermoplastic composite; A method is described that includes:

[0023] Any one or more of the following features may be relevant to any of the above aspects described herein, or any combination thereof.

[0024] In some configurations, the method may further include adding a crosslinking agent to the functionalized thermoplastic or thermoplastic dispersion, where the crosslinking agent is added to the extruder or to the extruded functionalized thermoplastic or thermoplastic dispersion to produce the binder.

[0025] In some configurations, the extruder is a twin screw extruder.

[0026] In some configurations, a twin-screw extruder includes two rotating screws within a housing between the inlet and outlet ends of the extruder.

[0027] In some configurations, the thermoplastic comprises waste plastic.

[0028] In some configurations, the thermoplastics may include a high melting point thermoplastic, such as polypropylene, and a low melting point thermoplastic, such as polyethylene, or a combination thereof.

[0029] In some configurations, the ratio of high melting point thermoplastic to low melting point thermoplastic is between 1:4 and 4:1.

[0030] In some configurations, for thermoplastics: a) increasing the melt flow index of thermoplastics; b) cleaning thermoplastics; c) milling the thermoplastic to reduce particle size variation of the thermoplastic; d) standardizing size / density; e) pelletizing to a particle size of 2-8 mm; or f) Any combination of one or more of (a) to (e) A pretreatment step may be carried out, including:

[0031] In some configurations, the thermoplastic is subjected to a characterization step that analyzes one or more physical properties of the thermoplastic.

[0032] In some configurations involving a pre-treatment step, increasing the melt flow index of the thermoplastic includes processing the thermoplastic through an extruder.

[0033] In some configurations involving a pre-treatment step, increasing the melt flow index of the thermoplastic involves adding a melt flow increasing additive to the extruder.

[0034] In some configurations, the melt flow increasing additive is selected from plasticizers, initiators, and combinations thereof.

[0035] In some configurations involving a pre-treatment step, increasing the melt flow index of the thermoplastic involves adding another thermoplastic having a higher melt flow index.

[0036] In some configurations that include a characterization step, the physical properties of the thermoplastic include the melt flow index, melting point, viscosity, glass transition temperature, density, tensile strength, or crystallinity of the thermoplastic.

[0037] In some configurations, the coupling agent is selected from a grafted compatibilizer or a reactive hydrogen donor.

[0038] In some configurations, the coupling agent is selected from glycidyl methacrylate, maleic anhydride, acrylic acid, glycidyl methacrylate, N-vinyl formamide, bismaleimide, or a silane.

[0039] In some configurations, at least a portion of the thermoplastic is reacted with the initiator in the extruder.

[0040] In some configurations, the thermoplastic is dispersed in water with the addition of a surfactant.

[0041] In some configurations, the cross-linking agent is selected from an organic peroxide or an isocyanate.

[0042] In some configurations, the isocyanate is added in an amount of 5% to 20% by weight of the binder.

[0043] In some configurations, the isocyanate is a blocked isocyanate.

[0044] In some configurations, the isocyanate is a diisocyanate.

[0045] In some configurations, the blocked isocyanate is added to an extruder that has been cooled to a temperature below the unblocking temperature of the isocyanate blocking agent.

[0046] In some configurations, the moisture content of the binder is between about 25% and about 75%.

[0047] In some configurations, the emulsification zone includes a dilution zone for adding additional water to achieve a thermoplastic to water ratio of about 0.8:1 to 1.8:1.

[0048] In some configurations, the binder and substrate fibers are mixed in a mixer to form a substantially homogeneous mixture.

[0049] In some configurations, the substrate fibers are selected from glass fibers, carbon fibers, aramid fibers, and combinations thereof.

[0050] In some configurations, the substrate fibers are selected from lignocellulosic materials selected from sawdust, wood fibers, wood particles, wood chips, wood sheets, coconut shells, rice straw or rice husks, barley straw, bamboo, and combinations thereof.

[0051] In some configurations, when the method includes forming a thermoplastic composite product, the composite mixture has a moisture content of about 5% to about 15%.

[0052] In some configurations, the plastic particles in the thermoplastic dispersion or binder have a particle size of less than 0.5 mm in length in any direction or axis.

[0053] In some configurations, the temperature of the melt zone is between about 140° C. and about 240° C., with subsequent zones having lower temperatures than the melt zone.

[0054] In some configurations, the binder has a degree of functionalization between 0.5% and 6%.

[0055] In some configurations, the characterization step comprises: Setting a predetermined range for the melt flow index of a thermoplastic; Processing thermoplastics through an extruder, Measuring the melt flow index of the processed thermoplastics; Comparing the measured melt flow index with a predetermined range of melt flow indices; and adjusting one or more conditions of the extruder so that the melt flow index of the processed thermoplastic is within a predetermined range, the one or more conditions including: The ratio of different types of thermoplastics, Processing of thermoplastics by extrusion, The proportion of PP in thermoplastics, The amount of plasticizer added to the thermoplastic, Extruder zone temperatures, The degree of agitation in the extruder, or Residence time of thermoplastics in the extruder Any combination of, or selected from one or more of; Includes.

[0056] In some configurations, the method comprises: a) Elastic modulus of approximately 1,000 to approximately 4,000 MPa b) Modulus of rupture of about 10 to about 25 MPa c) Screw retention force of approximately 200 to 500 N d) a density of about 550 to about 1,100 kg / m³, or e) Any combination of one or more of (a) to (d) The present invention can be used to manufacture lignocellulosic thermoplastic composite boards having the following properties:

[0057] In some configurations, the composite board is MoR exceeding 1000 MPa, MoE above 8 MPa, IB greater than 0.2, Moisture content greater than approximately 5%, or Moisture content less than approximately 15% It comprises at least one of the following:

[0058] In some configurations, the thermoplastic dispersion further comprises at least one surfactant.

[0059] In some configurations, the thermoplastic is functionalized with a coupling agent to produce a thermoplastic dispersion.

[0060] In some configurations, the waste plastic is approximately 55% to 90% polyethylene by weight.

[0061] In some configurations, the thermoplastic is or includes a plastic film.

[0062] In some configurations, the cellulose content in the waste thermoplastic is less than 5, 6, 7, 8, 9, or 10 wt. %, and a suitable range can be selected between any of these values.

[0063] In some configurations, the twin screw extruder comprises two co-rotating screws.

[0064] In some configurations, the thermoplastic for addition to the inlet end of the twin screw extruder is sized small enough to feed into the inlet end.

[0065] In some configurations, the twin screw extruder is equipped with external heat input to the melt zone.

[0066] In some configurations, the melt zone generates heat from a combination of external heat input and frictional heat.

[0067] In some configurations, the melt zone generates heat from friction.

[0068] In some configurations, the twin screw extruder includes cooling passages.

[0069] In some configurations, the cooling passages are in the emulsion zone and further include one or more water injection ports.

[0070] In some configurations, the coupling agent is in powder form and is mixed with the thermoplastic at the inlet end of the twin-screw extruder.

[0071] In some configurations, the coupling agent is added to the melt zone through an injector port in the melt zone.

[0072] In some configurations, the thermoplastic polymer is functionalized with one or more hydrogen groups by a reactive hydrogen donor.

[0073] In some configurations, the reactive hydrogen donor is selected from short to medium chain compounds containing an alkene and at least one of an alcohol, a carboxylic acid, or an amine functional group.

[0074] In some configurations, the reactive hydrogen donor is provided by one or more compounds containing a carboxylic acid functionality.

[0075] In some configurations, the compound having a carboxylic acid functionality is acrylic acid, itaconic acid or its monoester, itaconic anhydride, methacrylic acid, acrylic acid, maleic acid or its monoester, ethacrylic acid, fumaric acid or its monoester, crotonic acid, vinyl sulfonic acid, 2-methacryloyloxy-ethanesulfonate, styrene sulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid (AMPS), vinylphosphonic acid, 2-(methacryloyloxy)ethyl phosphate, The carboxylic acid may be selected from mesaconic acid, citraconic acid or its monoester, glutaconic acid or its monoester, methylmaleic acid or its monoester, methylmaleic anhydride, citraconic anhydride, glutaconic anhydride, endobicyclo-[2,2,1]-5-heptene-2,3-dicarboxylic acid or its monoester (such as the monomethyl ester of heptene-2,3-dicarboxylic acid), and endobicyclo-[2,2,1]-5-heptene-2,3-dicarboxylic acid anhydride, or a combination thereof.

[0076] In some configurations, the reactive hydrogen donor is selected from N-methylethanolamine, N-methylisopropylamine, 4-aminocyclohexanol, 1,2-diaminotheane, 1,3-diaminopropane, diethylenetriamine, toluene-2,4-diamine, and toluene-1,6-diamine. Aliphatic compounds containing 2 to 8 carbon atoms are preferred. Ethylenediamine, monomethanolamine, and propylenediamine, or combinations thereof.

[0077] In some configurations, the reactive hydrogen donor provides an alcohol functionality.

[0078] In some configurations, the alcohol functional group is selected from PVOH.

[0079] In some configurations, the alcohol functionality can be selected from α,β-olefinically unsaturated monocarboxylic acids, such as hydroxyalkyl esters, having primary or secondary hydroxyl groups.

[0080] In some configurations, the hydroxyalkyl ester of an α,β-olefinically unsaturated monocarboxylic acid may be derived from acrylic acid, methacrylic acid, crotonic acid, and / or isocrotonic acid, preferably from (meth)acrylic acid, wherein the hydroxyalkyl group may contain, for example, 1 to 10 C atoms, preferably 2 to 6 C atoms.

[0081] In some configurations, the hydroxyalkyl ester of an α,β-olefinically unsaturated monocarboxylic acid having a primary hydroxyl group can be hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, hydroxyamyl (meth)acrylate, or hydroxyhexyl (meth)acrylate.

[0082] In some configurations, the alcohol functionality can be selected from monoesterification products of (meth)acrylic acid with dihydric alcohols having 2 to 8 carbon atoms, such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate; ε-caprolactone-modified products of monoesterification products of (meth)acrylic acid with dihydric alcohols having 2 to 8 carbon atoms; allyl alcohol; and the like.

[0083] In some configurations, the grafted compatibilizer is a reactive monomer.

[0084] In some configurations, the reactive monomer is selected from maleic anhydride, glycidyl methacrylate, acrylic acid, bismaleimide, silane, N-vinylformamide, or titanate coupling agents.

[0085] In some configurations, the silane coupling agent is selected from vinyltriethoxysilane or gamma-aminopropyltriethoxysilane, the addition of which can improve flexural strength and modulus in the absence of other additives.

[0086] In some configurations, the initiator comprises a free radical-generating initiator. The initiator can be selected from organic peroxides such as benzoyl peroxide, octanoyl peroxide, lauroyl peroxide, stearoyl peroxide, cumene hydroperoxide, tert-butyl peroxide, certi-butyl peroxylaurate, tert-butyl peroxyisopropyl carbonate, tert-butyl peroxyacetate, and diisopropylbenzene hydroperoxide. Initiation can include UV or electron beam irradiation of the thermoplastic.

[0087] In some configurations, the initiator is dicumyl peroxide.

[0088] In some configurations, the method includes a single twin screw extruder that is operated in a continuous process so that the extruded thermoplastic reacts with the coupling agent.

[0089] In some configurations, the single twin-screw extruder is modular, with a first module including a melting zone and a second module including an emulsification zone, wherein the thermoplastic is initially processed in the first module, the thermoplastic being selected from a thermoplastic that reacts with a coupling agent to form a functionalized molten thermoplastic and a thermoplastic that does not react with a coupling agent to form a molten thermoplastic; The mixture of functionalized molten thermoplastic and molten thermoplastic is processed in a second module.

[0090] In some configurations, the blend comprises about 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, or 90% by weight of the functionalized molten thermoplastic, and a suitable range can be selected between any of these values.

[0091] In some configurations, the process includes two or more twin-screw extruders.

[0092] In some configurations, the first twin-screw extruder comprises at least a melt zone for producing molten thermoplastics, and the second twin-screw extruder comprises at least a melt zone for producing molten thermoplastics, at least one of the thermoplastics being a functionalized molten thermoplastic; The functionalized molten thermoplastic and the molten thermoplastic are mixed to form an emulsion.

[0093] In some configurations, the emulsion comprises about 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, or 90% by weight of the functionalized molten thermoplastic, and a suitable range can be selected between any of these values.

[0094] In some configurations, the emulsification zone comprises a mixing zone and a shear zone.

[0095] In some configurations, water and surfactant are added to the mixing zone via an inlet to produce a first emulsified thermoplastic.

[0096] In some configurations, the first emulsified thermoplastic is subjected to shear in a shear zone to produce a functionalized thermoplastic emulsion.

[0097] In some configurations, shear force is provided to atomize the thermoplastic within the reactive emulsion.

[0098] In some configurations, the phase change occurs by adding water and surfactant to the emulsification zone.

[0099] In some configurations, water is added along with the cross-linking agent.

[0100] In some configurations, the cross-linking agent is selected from a participatory cross-linking agent or a non-participatory cross-linking agent.

[0101] In some configurations, the participatory crosslinker is selected from isocyanates.

[0102] In some configurations, the non-participative crosslinking agent is selected from organic peroxides.

[0103] In some configurations, the participatory crosslinker is added only when the thermoplastic has reacted with the hydrogen donor.

[0104] If a non-participating crosslinker such as an organic peroxide is added, it is added at about 0.1%, 0.5%, 1%, 2%, 3%, 4%, or 5% by weight of the emulsion, and a suitable range can be selected between any of these values.

[0105] If a participative crosslinker such as an isocyanate is added, it is added at about 0.1%, 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, or 15% by weight of the emulsion, and a suitable range can be selected between any of these values.

[0106] t.

[0107] In some configurations, the crosslinking agent is mixed with the emulsion immediately prior to the manufacture of the fiberboard.

[0108] In some configurations, the binder mixture is mixed with the wood chips prior to the production of the particle board.

[0109] In some configurations, the composite mixture is subjected to sufficient pressure to reduce the thickness of the composite mixture and heated to between about 140°C and about 220°C to form a composite panel.

[0110] In some configurations, the feedstock thermoplastic material comprises less than 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, or 1% cellulosic material by weight of the feedstock thermoplastic material.

[0111] Reference to a range of numerical values ​​disclosed herein (e.g., 1 to 10) is intended to include reference to every rational number within that range (e.g., 1, 1.1, 2, 3, 3.9, 4, 5, 6, 6.5, 7, 8, 9, and 10), as well as any rational number range within that range (e.g., 2 to 8, 1.5 to 5.5, and 3.1 to 4.7).

[0112] The present invention may be broadly described as consisting of the parts, elements, and features individually or collectively referred to or indicated in the specification of this application, and any combination of any two or more of said parts, elements, or features, and where specific integers having known equivalents in the technical field to which the invention pertains are referred to herein, such known equivalents are deemed to be incorporated herein as if individually set forth.

[0113] Where this specification references external sources of information, including patent specifications and other documents, this is generally for the purpose of providing background for discussing features of the present invention.

[0114] Unless otherwise stated, the citation of such sources should not be construed as an admission that such sources are prior art or form part of the common general knowledge in the art in any jurisdiction.

[0115] The invention will now be described, by way of example only, with reference to the following drawings. [Brief explanation of the drawings]

[0116] [Figure 1] 1 is a flow diagram of the described process for forming a plastic emulsion. [Figure 2] 2 is a flow diagram of the described process for forming a composite article from the plastic emulsion of FIG. 1. [Figure 3] FIG. 1 illustrates the expected reactions between various components. [Figure 4] FIG. 1 illustrates the expected reactions between various components. [Figure 5A] FIG. 1 is a schematic diagram of the TSE described. [Figure 5B] FIG. 1 is a schematic diagram of the TSE described. [Figure 5C] FIG. 1 is a schematic diagram of the TSE described. [Figure 5D] FIG. 1 is a schematic diagram of the TSE described. [Figure 6A] 1 is a flowchart of a portion of the described method. [Figure 6B] 1 is a flowchart of a portion of the described method. [Figure 6C] 1 is a flowchart of a portion of the described method. [Figure 7a] FIG. 1 is a schematic diagram of an alternative representation of the TSE described. [Figure 7b] FIG. 1 is a schematic diagram of an alternative representation of the TSE described. [Figure 7c] FIG. 1 is a schematic diagram of an alternative representation of the TSE described. [Figure 7d] FIG. 1 is a schematic diagram of an alternative representation of the TSE described. [Figure 7e] FIG. 1 is a schematic diagram of an alternative representation of the TSE described. [Figure 8a] DSC analysis of Sample 1a (industrial waste pelletized LDPE). [Figure 8b] 1 is the melt flow index at different temperatures. [Figure 8c] DSC analysis of Sample 1b. [Figure 8d] DSC analysis of sample 1c. [Figure 8e] DSC analysis of sample 1d. [Figure 9a] 1 is a graph comparing the melt flow index of different percentages of recycled PP at different temperatures. [Figure 9b] 1 is a graph comparing the melt flow index of different percentages of recycled PP at different temperatures. [Figure 9c] 1 is a graph comparing the melt flow index of different percentages of recycled PP at different temperatures. [Figure 9d] 1 is a graph comparing the melt flow index of different percentages of recycled PP at different temperatures. [Figure 9e] 1 is a graph comparing the melt flow index of different percentages of recycled PP at different temperatures. [Figure 10a] 1 is a graph comparing the MOE, MOR, and IB of eMDI boards and pMDI boards. [Figure 10b] 1 is a graph comparing the MOE, MOR, and IB of eMDI boards and pMDI boards. [Figure 10c] 1 is a graph comparing the MOE, MOR, and IB of eMDI boards and pMDI boards. [Figure 11] Figure 1 shows the effect of functionalized PE on wood fiber board strength. [Figure 12a] FTIR spectrum of rPP. [Figure 12b] 1 is an FTIR spectrum of rPP-g-St-GMA. [Figure 12c] These are microscopic images of rPP and rPP-St-GMA, respectively. [Figure 12d] These are microscopic images of rPP and rPP-St-GMA, respectively. [Figure 13a] 1 is a graph showing the MAPE and MOE of Luperox 231 at different weight percentages. [Figure 13b] 1 is a graph showing the MAPE and MOE of Luperox 231 at different weight percentages. [Figure 13c] 1 is a graph showing the MAPE and MOE of Luperox 231 at different weight percentages. [Figure 14a] 1 is a graph showing the MOE, MOR, and IB of mixed polymer fiber boards and the melt flow index of different PP:LDPE blends. [Figure 14b] 1 is a graph showing the MOE, MOR, and IB of mixed polymer fiber boards and the melt flow index of different PP:LDPE blends. [Figure 14c] 1 is a graph showing the MOE, MOR, and IB of mixed polymer fiber boards and the melt flow index of different PP:LDPE blends. [Figure 14d] 1 is a graph showing the MOE, MOR, and IB of mixed polymer fiber boards and the melt flow index of different PP:LDPE blends. [Figure 15a] The change in modulus of elasticity (MoE) for different board treatments is shown. [Figure 15b] The change in modulus of rupture (MoR) for different board treatments is shown. [Figure 15c] The internal bond strength (IB) for different board treatments is shown. [Figure 15d] Figure 1 shows the swelling ratio (SB) at 24 hours for different board treatments. DETAILED DESCRIPTION OF THE INVENTION

[0117] As used herein, the terms "cellulose," "cellulosic," or grammatical equivalents thereof refer to processed plant-based materials such as paper and cardboard, and exclude lignocellulosic materials.

[0118] As used herein, the terms "lignocellulose," "lignocellulosic," or grammatical equivalents thereof, refer to plant-based materials in which wood fibers remain substantially intact, such as wood chips, sawdust, wood particles, wood sheets, coconut shells, rice or rice husks, barley straw, bamboo, wood fibers, etc., and by definition excludes cellulose. References herein to lignocellulosic material, lignocellulose-based material, lignocellulosic substrate, and lignocellulosic fiber shall be read interchangeably.

[0119] As used herein, the term "comprising" means "consisting at least in part of." When interpreting descriptions containing this term herein, all features preceded by this term in the respective description must be present, although other features may also be present. Related terms such as "comprise" and "comprised" should be interpreted in the same way.

[0120] "Waste plastic," as referred to herein, means plastic that has been previously used in a product or process for one or more uses after the initial synthesis of its plastic polymer. Waste plastic has different properties compared to virgin plastic due to wear and tear from previous use and the recycling process that has followed one or more uses after the initial synthesis of its plastic polymer. Waste plastic may have been pre-processed, such as by manual, automated, or mechanical sorting, washing, or crushing. Waste plastic may come from household or industrial waste collection services, municipal recycling facilities, or other recyclers. In certain embodiments, waste plastic may include at least one of post-industrial (or pre-consumer) plastic and / or post-consumer plastic, and may include recycled plastic.

[0121] As used herein, "virgin plastic" refers to plastics containing plastic resins that have never been previously used in a product or process. It is a newly manufactured plastic material that does not contain recycled plastic components and is produced directly from petrochemical feedstocks such as natural gas or crude oil. Because virgin plastics have not undergone prior use or processing, they have consistent quality and properties. As such, they are often chosen for applications where specific structural, aesthetic, or hygienic properties are important, such as medical devices, high-quality consumer products, or food packaging.

[0122] As referred to herein, "dispersion" means a system in which particles of one substance (the dispersed phase) are dispersed or distributed throughout another substance (the dispersion medium). The particles may vary in size. A dispersion may include solid particles dispersed in a liquid, a liquid of one density dispersed in another immiscible liquid, or particles of one solid dispersed among particles of another solid.

[0123] As referred to herein, "emulsion" means a material comprising a combination of at least two immiscible fractions that are mixed or intermixed in a liquid or semi-liquid state. Emulsions according to the present disclosure are examples of dispersions, which do not necessarily comprise two liquids, but typically comprise a polymer in water, which may be a size-reduced, solidified polymer that has been heated and mixed to form the emulsion.

[0124] As referred to herein, "extruder" refers to a machine used to mix, push, or draw materials while heating them. The extruder may be a single-screw or twin-screw extruder, a co-rotating intermeshing twin-screw extruder, a co-kneader, a Banbury mixer, a high-pressure homogenizer, or any other machine equipped with internal screws or rotors to knead or mix materials under high pressure and temperature. Extruders typically consist of a heated barrel equipped with a rotating screw or kneading element. The raw materials, often in the form of pellets or granules, are fed into the barrel and melted and mixed by the combined action of the mechanical action of the screw and the heat from the barrel. The molten plastic is then forced through a die at the end of the barrel to form the desired shape.

[0125] "Micronization," as referred to herein, refers to a process that reduces the particle size of a material. Micronization can be achieved using a variety of methods, including, for example, extrusion in a single or twin screw extruder, chopping, mechanical crushing, crushing, grinding, sonication, micronization, cryogenic grinding, shearing, high pressure homogenization, microfluidization, and comminution.

[0126] A method for forming a thermoplastic composite product is described in which a source of thermoplastic is introduced into the inlet end of one or more extruders. Within the one or more extruders, most, if not all, of the thermoplastic is melted to form a melt zone within the extruder. The thermoplastic is further processed as follows: a) reacting at least a portion of a thermoplastic with a coupling agent to form a functionalized thermoplastic; b) dispersing a thermoplastic in water with stirring to form a thermoplastic dispersion; or c) treating a thermoplastic with (a) followed by (b) to produce a dispersion of a functionalized thermoplastic;

[0127] A crosslinking agent may then be added to the functionalized thermoplastic or thermoplastic dispersion to produce a binder. The crosslinking agent may be added in the extruder or to the extruded functionalized thermoplastic or thermoplastic dispersion.

[0128] If used, the binder is mixed with the substrate (in fiber form) to form a composite mixture, which is introduced into a press or mold and subjected to heat and pressure to form a thermoplastic composite product.

[0129] Thermoplastics (or thermosoftening plastics) are plastic polymers. Most thermoplastics have a high molecular weight. The polymer chains of thermoplastics are held together by intermolecular forces that weaken with increasing temperature, giving rise to a viscous liquid. In this state, thermoplastics can be remolded.

[0130] The thermoplastics can consist of virgin plastics, or waste plastics, or a mixture of virgin and waste plastics.

[0131] The present systems, methods, and apparatus can be used to process a variety of input plastics. In some embodiments, a majority of the input thermoplastic is selected from polypropylene, polyethylene, or a combination thereof. The input thermoplastic can include at least 60%, 65%, 70%, 75%, 80%, 85%, or 90% polypropylene or polyethylene, or a combination thereof, with suitable ranges selected from any of these values ​​(e.g., about 60 to about 90% by weight, about 60 to about 85% by weight, about 60 to about 80% by weight, about 65 to about 90% by weight, about 65 to about 80% by weight, or about 70 to about 90% by weight of the plastic). The polyethylene can constitute 55%, 60%, 65%, 70%, 75%, 80%, 85%, or 90% by weight of the thermoplastic, and a suitable range can be selected from any of these values ​​(e.g., about 55 to about 90% by weight, about 55 to about 80% by weight, about 55 to about 70% by weight, about 60 to about 90% by weight, about 60 to about 85% by weight, about 60 to about 80% by weight, about 65 to about 90% by weight, about 65 to about 80% by weight, or about 70 to about 90% by weight of the plastic).

[0132] Waste plastics provide a useful source of plastics for this process. In many countries, waste plastics pose an environmental problem as societies struggle to economically and safely recycle or dispose of them. The source waste plastic may be, for example, the type of plastic obtained from a waste recycling process. However, it will be understood that various types of input plastics can be used depending on the desired output slurry.

[0133] Challenges in the processing of waste plastics include the variability in polymer type and size, as well as the presence of additives and contaminants. For example, post-consumer waste is composed of a variety of different polymers and may contain organic and inorganic contaminants, such as food waste, glass, and foil. One step to enabling effective processing of waste plastics is to rapidly and efficiently characterize the waste. Processing of waste plastics often requires knowledge of the physical and chemical properties of the waste plastics so that processing parameters can be optimally applied and the correct stoichiometry can be derived.

[0134] Thus, the methods provided herein can include a waste characterization step that includes analysis of one or more physical properties, which can include melt flow index, melting point, viscosity, glass transition temperature, density, tensile strength, crystallinity, or any combination thereof.

[0135] Similarly, the methods provided herein can include a waste characterization step that includes analysis of one or more chemical properties, which can include chemical formula, molecular weight, monomer content, degree of branching, crosslink density, oxidative stability, or any combination thereof.

[0136] The waste plastics may include any one or combination of polyethylene terephthalate (PETE or PET), high density polyethylene (HDPE), polyvinyl chloride (PVC), low density polyethylene (LDPE), linear low density polyethylene (LLDPE), polypropylene (PP), polystyrene or expanded polystyrene (PS), polycarbonate, polylactic acid, acrylic, acrylonitrile butadiene, styrene, fiberglass, rubber, paper, and nylon. The waste plastic mixture may be derived, for example, from a mixed plastic waste stream.

[0137] Considering the widespread use of plastics in society, it will be understood that waste plastics can come from everyday waste such as plastic bottles (e.g., milk, carbonated drinks, water bottles, cleaning products), plastic containers (e.g., for industrial products such as oil and food), and packaging (whether rigid or flexible), although the list of waste products is very extensive.

[0138] The waste plastics processed according to the present invention may be subjected to one or more pretreatment steps. These pretreatment steps may be carried out in a pretreatment facility equipped with all the equipment, lines, and controls necessary to pretreat the waste plastics. Alternatively, the waste plastics may not undergo pretreatment, and the waste plastic stream may not undergo pretreatment prior to any of the downstream processes described herein.

[0139] The waste plastic source pretreatment facility may include at least one separation step or zone. The separation step or zone may be configured to separate the waste plastic stream into two or more streams enriched in a particular type of plastic. Such separation may be advantageous if the waste plastic undergoes a chemical recycling process, such as functionalization.

[0140] Some thermoplastics, such as plastic film, are difficult to recycle or reuse. Plastic film can be used in this process, which is important given the lack of other options for recycling plastic film. The process's ability to reuse plastic film is due to the screw extruder's ability to efficiently melt, compress, and mix. Additional benefits include the ability to inject additives and reactive components into the molten plastic and mix them in the final product. The process uses extrusion technology to produce a binder that can be used to manufacture new composite products.

[0141] One source of plastic can be shredded plastic, i.e., it is broken into pieces that can fit into the inlet of a twin-screw extruder. Various methods for shredding plastic products are known, including the use of cutters and / or extruders, shredders, granulators, or grinders. Cutters and extruders (see, for example, U.S. Pat. No. 9,744,689) can include one or more knives that rotate within a housing so that plastic introduced into the housing is cut by the knives into smaller particles. In some machines, the action of the knives (i.e., heat generated by friction) can begin to melt or melt the plastic, and such molten or partially molten plastic can enter an extruder, where a screw moves the plastic away from the cutting blades. The plastic can then be extruded and chopped into small pellets at the extruder outlet.

[0142] Shredders (see, e.g., U.S. Pat. No. 6,241,170), granulators (see, e.g., U.S. Pat. No. 6,749,138), and crushers (see, e.g., U.S. Pat. No. 5,547,136 or German Patent No. 19614030A1) similarly include one or more cutting wheels or rollers rotating within a housing, which act on the plastic as it passes between the cutting wheel or roller and the inner surface of the housing, thereby reducing the size of the plastic. Alternatively, the plastic may be passed between two or more rows of knives or rollers, sometimes overlapping, which cut or crush the plastic as it passes through.

[0143] Such processes typically use a rotating knife or bed knife, the rotation of which cuts the plastic into smaller particles or pieces.

[0144] It will be understood that plastic waste may contain some contaminants. In some embodiments, the waste thermoplastic may contain some cellulosic material, such as paper or labels. Preferably, the thermoplastic contains less than about 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, or 10% cellulosic material by weight of the thermoplastic, and suitable ranges can be selected between any of these values.

[0145] The functionalization and / or emulsification processes described herein may require the use of pretreated waste thermoplastics. This may be necessary before waste plastics, such as plastic film, or thin "flakes" of thermoplastics, such as common plastic bottles, can be used in the methods described. Pelletizing the waste plastics before processing ensures uniformity in particle size and density, allowing for better control of the flow and melting of the material. The smaller and more uniform the pellet size, the more efficiently the melting and mixing can be performed during the extrusion process. Herein, the pelletization pretreatment step may include preparing pellets having a size of about 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, or 8 mm, and a suitable range may be selected from any of these values ​​(e.g., about 2 mm to about 8 mm, about 2 mm to about 6 mm, about 2 mm to about 5 mm, about 3 mm to about 8 mm, about 3 mm to about 7 mm, about 3 mm to about 6 mm, about 4 mm to about 8 mm, or about 4 mm to about 6 mm). This allows for more uniform functionalization and emulsification when these processes are employed. Additionally, it is believed that the pellets can be efficiently fed at a predetermined rate to ensure that the stoichiometric ratios during functionalization and emulsification are maintained.

[0146] The melt flow index (MFI) of the processed thermoplastic can be increased after passing through the extruder. Higher melt flow thermoplastics melt and spread more effectively, providing processing advantages during board formation and enhancing the mechanical locking between the thermoplastic and the lignocellulosic material.

[0147] The method can provide for pre-treatment of the thermoplastic, which includes increasing the melt flow index (MFI) of the thermoplastic. a) before functionalization, b) after functionalization and before emulsification, or c) without functionalization and before emulsification, It can be implemented.

[0148] Functionalization is Functionalizing thermoplastics, and Increasing the melt flow index It may include both.

[0149] Step (a) above can increase the reactivity of the thermoplastic when combined with a crosslinking agent. Step (b) above can improve extruder processing, enhance emulsification, and reduce particle size. Increasing the melt flow index (MFI) of the thermoplastic can be achieved by one or more of the following: Adding an additive to the extruder to increase the melt flow index. The additive may be a plasticizer and / or an initiator. The initiator may be an initiator described herein, such as DCP. The plasticizer may be tall oil or a polyolefin-specific plasticizer. Processing thermoplastics through an extruder to reduce the molecular weight of the thermoplastic molecules. When the thermoplastic contains polypropylene, it is amenable to this method due to the branched nature of its molecules, and processing can shorten the chain length of the polymer. Blending a thermoplastic, such as waste thermoplastic, with a second thermoplastic.

[0150] Step (c) can include combining the first thermoplastic with a second thermoplastic having a higher melt flow index. That is, the first thermoplastic can include a low-melting-point thermoplastic, and the second thermoplastic can include a high-melting-point thermoplastic. The second thermoplastic can include polypropylene. The second thermoplastic (including the high-melting-point thermoplastic) can comprise 10%, 20%, 30%, 40%, or 50% of the total weight of the thermoplastics, with suitable ranges selected from any of these values ​​(e.g., about 10 to about 50%, about 10 to about 40%, about 10 to about 30%, about 20 to about 50%, about 20 to about 49%, or about 30 to about 50% of the total weight of the thermoplastics). Example 4 demonstrates the effect on the melt flow index of the addition of various amounts of recycled polypropylene. This demonstrates that the addition of recycled polypropylene provides a method for increasing the melt flow index of a mixed waste thermoplastic composition.

[0151] As used herein, high melting point thermoplastics have a melting point above 130°C, and low melting point thermoplastics have a melting point below 130°C.

[0152] The melt flow index of a thermoplastic can be increased by processing it in an extruder with the addition of an initiator. This is believed to be particularly effective in processing polypropylene, as the initiator abstracts hydrogen from the polymer backbone, causing a decrease in molecular weight due to chain scission. Therefore, in one embodiment, the melt flow index of a thermoplastic can be increased by using an extruder for processing thermoplastics, including polypropylene. The initiator in this example can be added to the extruder or to the feed material before it enters the extruder.

[0153] FIG. 6A illustrates an example of a method described herein, in which: The thermoplastic is functionalized in the extruder to form a functionalized thermoplastic; The functionalized thermoplastic is mixed with a crosslinker and a base material in a mixer to form a binder mix; The binder mix is ​​formed into a mat for pressing in a press. Heat and pressure are applied to the mat to produce a composite product.

[0154] The composite product may undergo post-processing steps such as cutting and laminating to form a useful product. The thermoplastic may undergo at least one of pre-treatment (e.g., washing or sorting) and / or characterization steps. Example 10 demonstrates the preparation of wood fiber board using a combination of functionalized PE and an organic peroxide crosslinker.

[0155] As shown in Figure 6B, the thermoplastic does not have to be functionalized in the extruder. The thermoplastic may already be functionalized, or may not require functionalization to obtain a useful composite product. Figure 6B illustrates one example of a method described herein, in which: at least a portion of the thermoplastic is sufficiently melted in the extruder and mixed with water to form a thermoplastic dispersion; The dispersion is mixed with a crosslinker and a base material in a mixer to form a binder mix; The binder mix is ​​formed into a mat for pressing in a press. Heat and pressure are applied to the mat to produce a composite product.

[0156] The composite product may undergo post-processing steps such as cutting and laminating to form a useful product. The thermoplastic may undergo at least one of pre-processing (e.g., cleaning or sorting) and / or characterization steps.

[0157] Examples 2, 3, 5, and 6 show various examples of thermoplastic dispersions that can be produced for the preparation of composite boards.

[0158] As shown in Figure 6C, thermoplastics can be both functionalized (to form a functionalized thermoplastic) and dispersed (to form a thermoplastic dispersion). Figure 6C shows an example of a method described herein, in which: the thermoplastic is functionalized in the extruder to form a functionalized thermoplastic; at least a portion of the functionalized thermoplastic is sufficiently melted in an extruder and mixed with water to form a thermoplastic dispersion; The thermoplastic dispersion is mixed with the crosslinker and the base material in the mixer to form a binder mix; The binder mix is ​​formed into a mat for pressing in a press. Heat and pressure are applied to the mat to produce a composite product.

[0159] The composite product may undergo post-processing steps such as cutting and laminating to form a useful product. The thermoplastic may undergo at least one of pre-processing (e.g., cleaning or sorting) and / or characterization steps.

[0160] Examples 6, 7, 8, and 10 demonstrate the effective preparation of binders and their use in making composite boards.

[0161] It will be understood that the binder mixes referred to herein can be used in the manufacture of various composite materials or adhesives, such as those described below. In one embodiment, the substrate comprises a lignocellulosic material / substrate.

[0162] sensualization The methods described herein can include functionalizing thermoplastics to improve their reactivity with crosslinkers in preparing binders that can be used in a variety of applications, including combining them with lignocellulosic materials / substrates to form plastic composite products.

[0163] The methods described herein can produce a composite material including: Introducing the thermoplastic into the extruder; · reacting a thermoplastic with a coupling agent to form a functionalized thermoplastic; blending the functionalized thermoplastic with a crosslinker to form a binder; and · Mixing a binder with a cellulosic substrate to form a composite mixture.

[0164] The process may further include applying heat and pressure to the binder mix to produce a composite product.

[0165] Most plastic waste, especially PP and PE, is hydrophobic. Lignocellulosic fibers are hydrophilic. Therefore, it can be difficult to mix the two. Coupling agents, such as grafted compatibilizers, can be used that have both hydrophobic and hydrophilic functional groups, thereby allowing the crosslinker to bond to the thermoplastic.

[0166] The thermoplastic introduced into the extruder can be fully melted in the melt zone of the extruder. The coupling agent can be added to the melted thermoplastic in the melt zone. The functionalization of the thermoplastic waste with the coupling agent can be carried out simultaneously in the extruder or sequentially in multiple extruders or modular extruders.

[0167] Without wishing to be bound by theory, differences exist in the chemical structure and / or polarity of thermoplastic polymers and lignocellulosic fibers. These differences are believed to result in weak interfacial adhesion. For example, polyolefins are hydrophobic, while lignocellulosic fibers are hydrophilic, meaning they repel each other. Poor interfacial adhesion can result in reduced tensile strength, reduced strength of thermoplastic composite products, and potentially reduced strength of final products, such as plastic-lignocellulosic composite boards. Coupling agents can add functional groups that provide available hydrogen or can be grafted onto the polymer to change polarity and form favorable interactions with lignocellulosic materials. These favorable interactions with lignocellulosic materials can strengthen interfacial adhesion. When a crosslinking agent is used, the coupling agent can form bonds with the crosslinking agent.

[0168] At least one coupling agent can be added to the extruder with the thermoplastic. One or more coupling agents can be added before the extruder is heated and running. One or more coupling agents can be added after the extruder is initially heated and running.

[0169] The amount of each coupling agent added may be about 1 wt%, 2 wt%, 3 wt%, 4 wt%, or 5 wt% of the thermoplastic, and a suitable range can be selected from any of these values ​​(e.g., about 1 wt% to about 5 wt%, about 1 wt% to about 4 wt%, about 1 wt% to about 3 wt%, about 2 wt% to about 5 wt%, about 2 wt% to about 4 wt%, about 3 wt% to about 5 wt%, or about 3 wt% to about 4 wt% of the thermoplastic).

[0170] When different types of coupling agents are added, the total amount of coupling agents added may be 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, or 10% by weight of the thermoplastic, and a suitable range may be selected between any of these values ​​(e.g., about 2% to about 10% by weight of the thermoplastic, about 2% to about 8% by weight, about 2% to about 9% by weight, about 2% to about 10 ... About 7% by weight, about 3% to about 10% by weight, about 3% to about 9% by weight, about 3% to about 7% by weight, about 3% to about 6% by weight, about 4% to about 10% by weight, about 4% to about 9% by weight, about 4% to about 8% by weight, about 5% to about 10% by weight, about 5% to about 9% by weight, about 5% to about 8% by weight, about 6% to about 10% by weight, about 6% to about 8% by weight, about 7% to about 10% by weight, or about 7% to about 9% by weight.

[0171] The degree of functionalization of a polymer backbone refers to the extent to which functional groups are attached to the main chain of the polymer. In polymer chemistry, functional groups are specific atomic groups present in a molecule that are responsible for the chemical reactions characteristic of that molecule. The "degree of functionalization" quantifies how many of these groups are attached to the polymer. For example, in a functionalized polymer, not all repeat units have functional groups attached. The degree of functionalization referred to herein refers to the percentage of repeat units of the polymer that are modified with functional groups. The degree of functionalization is controlled during the reactive extrusion process.

[0172] Methods of preparing functionalized thermoplastics or using thermoplastics functionalized according to the methods described herein are described where the degree of functionalization is in the range of 0.5%, 1%, 2%, 3%, 4%, 5%, or 6%, and a suitable range can be selected between any of these values ​​(e.g., about 0.5% to about 6%, about 0.5% to about 5%, about 0.5% to about 4%, about 0.5% to about 2%, about 1% to about 6%, about 1% to about 5%, about 1% to about 4%, about 2% to about 6%, about 2% to about 5%, about 3% to about 6%, or about 3% to about 4%). The functionalized thermoplastic can include PE or PP, or a blend of PE and PP. Methods of measuring the degree of functionalization will be known to those skilled in the art. For example, the method can include the use of FTIR and / or acid-base titration.

[0173] In one example, the coupling agent comprises the monomer GMA. The GMA can be added to the extruder via a feed, either simultaneously with the thermoplastic or sequentially. In one example, the GMA is added to the melt zone of the extruder via an injector. The amount added depends on the degree of functionalization desired. GMA can be added in the range of 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, or 10% by weight of the thermoplastic, and a suitable range can be selected from any of these values ​​(e.g., about 2% to about 10% by weight of the thermoplastic, about 2% to about 8%, about 2% to about 7%, about 3% to about 10% by weight, about 3% to about 9%, about 3% to about 7%, about 4% to about 10% by weight, about 4% to about 9%, about 4% to about 8%, about 5% to about 10% by weight, about 5% to about 8%, or about 6% to about 10% by weight). Addition of high proportions of coupling agent can result in undesirable phase separation, where contrasting hydrophilic and hydrophobic reactants prevent effective mixing. This can result in undesired homopolymerization, resulting in self-reaction of the monomers, or in degradation of the polymer, resulting in loss of monomer mixing / miscibility.

[0174] Example 8 describes the functionalization of recycled polypropylene with GMA. Analysis showed that the particle size of the treated polypropylene functionalized with GMA was smaller than the unfunctionalized material. When this material is processed in an extruder to emulsify and produce a thermoplastic dispersion, this smaller particle size is expected to result in smaller particle size in the resulting thermoplastic dispersion, which in turn will improve the strength of wood fiberboards containing dispersions containing crosslinkers such as isocyanates.

[0175] The coupling agent may be added to the extruder in the form of a powder or other solid. The coupling agent may be selected from a grafted compatibilizer, a reactive hydrogen donor, or a combination thereof.

[0176] Grafting comonomers can be used to increase the compatibility of the coupling agent with the thermoplastic. Styrene has an affinity for both the monomer and polymer and acts as a cosolvent, so it can be used to crosslink the monomer and polymer.

[0177] Grafted compatibilizers promote adhesion between immiscible or incompatible components of a blend or composite. Without compatibilization, the mechanical properties of the final product would be impaired. For example, grafted compatibilizers can improve the cohesion between inherently hydrophilic wood chips and inherently hydrophobic PP / PE. Grafted compatibilizers work by grafting chemical groups onto the polymer backbone, altering the basic characteristics of the polymer chain and thereby increasing its "compatibility" with the components of the composite. Grafted compatibilizers possess functional groups compatible with each component in the composite. They can thus "lock" the two incompatible components together, lowering the interfacial tension and promoting finer dispersion and better adhesion between the components.

[0178] The coupling agent or grafted compatibilizer can be selected from maleic anhydride, acrylic acid, glycidyl methacrylate, N-vinylformamide, bismaleimide, or silane. The use of N-vinylformamide can improve flexural strength and modulus. The silane-based grafted compatibilizer can be selected from vinyltriethoxysilane or r-aminopropyltriethoxysilane. The grafted compatibilizer can be selected from titanate coupling agents.

[0179] Maleic anhydride (MA) can be used as a grafting compatibilizer or coupling agent to form maleated polyethylene or maleated polypropylene. Maleated polyethylene is formed by reacting polyethylene with maleic anhydride. Maleated polypropylene is formed by reacting polypropylene with maleic anhydride. The anhydride functional groups of MA can interact with the surface hydroxyl groups of wood or lignocellulosic polymers during composite board manufacturing. Also, during composite board manufacturing, the carbon chains of maleic acid copolymers can crosslink with unfunctionalized polymer matrices due to their similar polarity. Adding sufficient amounts of maleic anhydride can form maleated thermoplastics. Without wishing to be bound by theory, maleic anhydride can form bonds with hydroxy groups on lignocellulosic fibers during composite board manufacturing. The hydroxy group can react with one of the carbonyls on the maleic anhydride, forming a covalent bond between the oxygen of the lignocellulose and one of the carbonyl carbons on the maleic anhydride. This causes ring opening, allowing the formation of a carboxylic acid moiety at the other carbonyl. The resulting carboxylic acid can then form further bonds with hydroxyls of other lignocellulosic materials or crosslinkers such as diisocyanates. The polymer chains attached to maleic acid can then form favorable interactions with the non-maleic plastic matrix through chain entanglement, resulting in stronger interfacial adhesion. Hydrogen bonding between the lignocellulose hydroxyls and the carboxylic acid hydroxyls is also thought to contribute to the favorable interactions.

[0180] Example 6 outlines an experiment in which maleic anhydride-functionalized polyethylene (MAPE) was used with Luperox 231 as a crosslinker to form wood fiber composite boards. The binder was prepared by blending and emulsifying LDPE to form a thermoplastic dispersion. As a result, boards with MAPE exhibited significantly higher strength (MoE) compared to boards without MAPE. This example demonstrates that MAPE improved the adhesion of LDPE to wood fiber in the fabrication of composite boards.

[0181] The amount of grafted compatibilizer added may be about 1 wt%, 2 wt%, 3 wt%, 4 wt%, or 5 wt% of the thermoplastic, and a suitable range can be selected from any of these values ​​(e.g., about 1 wt% to about 5 wt%, about 1 wt% to about 4 wt%, about 1 wt% to about 3 wt%, about 2 wt% to about 5 wt%, about 2 wt% to about 4 wt%, about 3 wt% to about 5 wt%, or about 3 wt% to about 4 wt% of the thermoplastic).

[0182] In one embodiment, glycidyl methacrylate is used as a grafted compatibilizer or coupling agent to form a functionalized thermoplastic.

[0183] An initiator may be added along with the grafting compatibilizer or functionalizing agent. The initiator is added to promote thermal dissociation and generate free radicals to promote grafting. In one example, the initiator includes a free radical-generating initiator.

[0184] The combined use of initiators and functionalization of thermoplastics has been investigated. Thermoplastics can be functionalized with glycidyl methacrylate (GMA), where the thermoplastics can be high-melting point thermoplastics such as polypropylene, low-melting point thermoplastics such as polyethylene, or a combination thereof. As described in Example 8, processing high-melting point thermoplastics such as PP in the presence of an initiator was found to increase the melt flow, which facilitated size reduction and better emulsification of the waste plastic.

[0185] The methods described herein can include an initial step of treating a high-melting-point thermoplastic, such as PP, in the presence of an initiator, followed by combining the high-melting-point thermoplastic, such as PP, with a low-melting-point thermoplastic, such as PE, prior to emulsification in an extruder to prepare a thermoplastic dispersion described herein. The high-melting-point thermoplastic, such as polypropylene, or the low-melting-point thermoplastic, such as polyethylene, or both, can optionally be functionalized. The ratio of high-melting-point thermoplastic (such as polypropylene) to low-melting-point thermoplastic (such as polyethylene) can be from 1:4 to 4:1, and suitable ranges can be selected between any of these values ​​(e.g., about 4:1, about 3:1, about 2:1, about 1:1, about 1:2, about 1:3, or about 1:4).

[0186] For emulsion-based processes, it has been found preferable to minimize the viscosity difference between phases such as polymer and water, as this results in smaller particle sizes in the emulsion. Adding a high-melting-point thermoplastic, such as polypropylene, to form a thermoplastic composition is one example, as illustrated in Examples 3 and 4. High-melt-flow thermoplastics also offer advantages during board formation because they melt and spread more effectively, enhancing the mechanical anchorage between the plastic and the lignocellulosic material. Additionally, the hydrophilic nature of GMA enhances its adhesion to the lignocellulosic material and promotes uniform mixing.

[0187] The benefits of GMA grafting extend beyond the emulsion process. GMA's hydrophilic nature reduces the surface tension between immiscible phases, resulting in smaller droplets and finer dispersions. In addition, GMA and maleic anhydride (MAH) can function as potential compatibilizers, improving the homogeneity of blended plastics, which can positively impact properties such as melt flow.

[0188] The initiator may be selected from organic peroxides such as benzoyl peroxide, dicumyl peroxide, octanoyl peroxide, lauroyl peroxide, stearoyl peroxide, cumene hydroperoxide, tert-butyl peroxide, cert-butyl peroxylaurate, tert-butylperoxyisopropyl carbonate, tert-butyl peroxyacetate, and diisopropylbenzene hydroperoxide. Initiation may involve exposing the thermoplastic to ultraviolet or electron beam light.

[0189] The initiator may be selected from dicumyl peroxide.

[0190] Additionally, functionalization can be achieved using groups that provide "available hydrogen." The reactive hydrogen donor is a coupling agent and can be selected from acids such as acrylic acid or itaconic acid, or alcohols such as polyvinyl alcohol. The reactive hydrogen donor can be grafted onto the polymer backbone to form bonds with the lignocellulosic fiber or covalent bonds with the crosslinker (if included), as shown in Figures 3 and 4.

[0191] The amount of reactive hydrogen donor or coupling agent added may be about 1 wt %, 2 wt %, 3 wt %, 4 wt %, or 5 wt % of the thermoplastic, and a suitable range can be selected from any of these values ​​(e.g., about 1 wt % to about 5 wt %, about 1 wt % to about 4 wt %, about 1 wt % to about 3 wt %, about 2 wt % to about 5 wt %, about 2 wt % to about 4 wt %, about 3 wt % to about 5 wt %, or about 3 wt % to about 4 wt % of the thermoplastic).

[0192] Suitable reactive hydrogen donors can be selected from compounds containing at least one isocyanate-reactive functional group and a functional group suitable for grafting to a polyolefin backbone, where the isocyanate-reactive functional group contains a reactive hydrogen, an active hydrogen, or a Zerewitinoff-reactive hydrogen.

[0193] If a compound having an isocyanate-reactive functional group is not suitable for grafting to a polyolefin, one skilled in the art will understand that it can be modified to make it suitable for grafting, such as by introducing an alkene functional group or a short-chain alkene side chain. Examples of coupling agent compounds containing an isocyanate-reactive hydrogen atom include alcohols, glycols, mercaptans, carboxylic acids such as polybasic acids, amines, ureas, silanes, and amides.

[0194] The reactive hydrogen donor can be selected from compounds that provide acidic, alcoholic, or amine functional groups. Without wishing to be bound by theory, the groups with available hydrogens can hydrogen bond with the hydroxyls on the wood fibers, creating weak but favorable interactions. The groups with available hydrogens also provide the hydrogen and subsequent interaction necessary to form a urethane bond with the diisocyanate.

[0195] Preferred reactive hydrogen donors or coupling agents are selected from short to medium chain compounds containing an alkene and at least one of an alcohol, a carboxylic acid, or an amine functional group, which may include vinyl alcohol, acrylic acid, or itaconic acid.

[0196] Examples of suitable reactive hydrogen donors or coupling agents containing carboxylic acid functionality suitable for grafting include methacrylic acid, acrylic acid, maleic acid or its monoesters (such as monomethyl maleate), maleic anhydride, ethacrylic acid, fumaric acid or its monoesters (such as monomethyl maleate), crotonic acid, itaconic acid or its monoesters (such as monomethyl itaconate), itaconic anhydride, vinyl sulfonic acid, 2-methacryloyloxy-ethanesulfonic acid, styrene sulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid (AMPS), vinylphosphonic acid, 2-(methacryloyl)-2-methylpropanesulfonic ... hydroxyethyl phosphate, mesaconic acid, citraconic acid or its monoester (such as monomethyl citraconic acid), glutaconic acid or its monoester (such as monomethyl glutaconic acid), methylmaleic acid or its monoester (such as monomethyl methylmaleate), methylmaleic anhydride, citraconic anhydride, glutaconic anhydride, endobicyclo-[2,2,1]-5-heptene-2,3-dicarboxylic acid or its monoester (such as monomethyl ester of heptene-2,3-dicarboxylic acid), and endobicyclo-[2,2,1]-5-heptene-2,3-dicarboxylic acid anhydride.

[0197] Reactive hydrogen donors that may be suitable for grafting include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol and other pentanediols, 2-ethyl-1,3-hexanediol, 2-ethyl-1,6-hexanediol and other 2-ethyl-hexanediols, 1,6-hexanediol and other hexanediols, 2,2,4-hexanediol ... alkene derivatives of glycols such as trimethylpentane-1,3-diol, decanediol, dodecanediol, bisphenol A, hydrogenated bisphenol A, 1,4-cyclohexanediol, 1,4-bis(2-hydroxyethoxy)cyclohexane, 1,3-cyclohexanedimethanol, 1,4-cyclohexanediol, 1,4-bis(2-hydroxyethoxy)cyclohexane, 1,3-cyclohexanedimethanol, 1,4-cyclohexanediol, 1,4-bis(2-hydroxyethoxy)benzene, and Esterdiol 204 (propanoic acid, 3-hydroxy-2,2-dimethyl-, 3-hydroxy-2,2-dimethylpropyl ester, available from TCI America).

[0198] Amines that may be suitable for grafting include N-methylethanolamine, N-methylisopropylamine, 4-aminocyclohexanol, 1,2-diaminotheane, 1,3-diaminopropane, diethylenetriamine, toluene-2,4-diamine, and toluene-1,6-diamine. Aliphatic compounds containing 2 to 8 carbon atoms are preferred. Ethylenediamine, monomethanolamine, and propylenediamine.

[0199] Other acids that may be suitable for grafting include bis(hydroxymethyl)propionic acid, diaminobenzoic acid, bis(hydroxymethyl)acetic acid, 2,2,2-tri(hydroxymethyl)acetic acid, 2,2-bis(hydroxymethyl)propionic acid, 2,2-bis(hydroxymethyl)butyric acid, 2,2-bis(hydroxymethyl)pentanoic acid, 2,5-dihydroxy-3-methylpentanoic acid, 3,5-dihydroxy-3-methylpentanoic acid, 4,5-dihydroxy-3-methylpentanoic acid, 3,4-dihydroxy-3-methylpentanoic acid, 2,3-dihydroxy-3-methyl ... hydroxy-3-methylpentanoic acid, 2,4-dihydroxy-3-methylpentanoic acid, 2,3-dihydroxybenzoic acid, 2,4-dihydroxybenzoic acid, 2,5-dihydroxybenzoic acid, 2,6-dihydroxybenzoic acid, 3,4-dihydroxybenzoic acid, 3,5-dihydroxybenzoic acid, 2,3-dihydroxysuccinic acid, 2,5-diaminopentanoic acid, 3,5-diaminopentanoic acid, 4,5-diaminopentanoic acid, 2,3-dihydroxybenzenesulfonic acid, 3,4-dihydroxybenzenesulfonic acid, 2,4-dihydroxybenzenesulfonic acid, 2 ,5-Dihydroxybenzenesulfonic acid, 3,5-dihydroxybenzenesulfonic acid, 2,3-diaminobenzenesulfonic acid, 3,4-diaminobenzenesulfonic acid, 2,4-diaminobenzenesulfonic acid, 2,5-diaminobenzenesulfonic acid, 3,5-diaminobenzenesulfonic acid, 3,4-dihydroxy-2-toluenesulfonic acid, 3,4-diamino(xiamino)-2-toluenesulfonic acid, 4,5-dihydroxy-2-toluenesulfonic acid, 4,5-diamino-2-toluenesulfonic acid, 5,6-dihydroxy-2-toluenesulfonic acid Acid, 5,6-diamino-2-toluenesulfonic acid, 3,5-dihydroxy-2-toluenesulfonic acid, 3,5-diamino-2-toluenesulfonic acid, 3,6-dihydroxy-2-toluenesulfonic acid, 3,6-diamino-2-toluenesulfonic acid, 4,6-dihydroxy-2-toluenesulfonic acid, 4,6-diamino-2-toluenesulfonic acid, 2,4-dihydroxy-3-toluenesulfonic acid, 2,4-diamino-3-toluenesulfonic acid, 2,5-dihydroxy-3-toluenesulfonic acid, 2,5-diamino-3-toluenesulfonic acid, 2,6-Dihydroxy-3-toluenesulfonic acid, 2,6-diamino-3-toluenesulfonic acid, 4,5-dihydroxy-3-toluenesulfonic acid, 4,5-diamino-3-toluenesulfonic acid, 4,6-dihydroxy-3-toluenesulfonic acid, 4,6-diamino(dDiamino)-3-toluenesulfonic acid, 5,6-dihydroxy-3-toluenesulfonic acid, 5,6-diamino-3-toluenesulfonic acid, 2,3-dihydroxy-4-toluenesulfonic acid, 2,5 alkene derivatives of 2,5-dihydroxy-4-toluenesulfonic acid, 2,6-dihydroxy-4-toluenesulfonic acid, 2,6-diamino-4-toluenesulfonic acid, 3,5-dihydroxy-4-toluenesulfonic acid, 3,5-diamino-4-toluenesulfonic acid, 3,6-dihydroxy-4-toluenesulfonic acid, 3,6-diamino-4-toluenesulfonic acid, 5,6-dihydroxy-4-toluenesulfonic acid, and 5,6-diamino-4-toluenesulfonic acid.

[0200] An initiator may be added together with the reactive hydrogen donor. After addition, the initiator undergoes thermal dissociation to generate free radicals, which promote and facilitate grafting. In one embodiment, the initiator is selected from organic peroxides such as benzoyl peroxide, dicumyl peroxide, octanoyl peroxide, lauroyl peroxide, stearoyl peroxide, cumene hydroperoxide, tert-butyl peroxide, cert-butyl peroxylaurate, tert-butyl peroxyisopropyl carbonate, tert-butyl peroxyacetate, and diisopropylbenzene hydroperoxide.

[0201] The initiator may be selected from dicumyl peroxide. The initiator may be mixed with the materials before they enter the extruder. Alternatively or additionally, the initiator may be injected into the extruder in the melt zone or after the melt zone. The initiator is preferably injected after effective mixing of the polymer and coupling agent to ensure uniform dispersion and efficient radical generation. The initiator may be dissolved in the coupling agent (e.g., GMA) or in a suitable organic solvent (as in the case of maleic anhydride, which is solid at room temperature).

[0202] The methods described herein produce thermoplastic dispersions or emulsions. The emulsions can be prepared from different portions of thermoplastic, where one portion of the thermoplastic has been functionalized with a coupling / functionalizing agent to form a functionalized thermoplastic portion, and another portion may be unfunctionalized thermoplastic that has not been subjected to the functionalization treatment. The resulting thermoplastic dispersions or emulsions can include particulate thermoplastic, where about 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 100% by weight of the particulate thermoplastic in the emulsion is functionalized thermoplastic, with the remaining thermoplastic, if present, being unfunctionalized thermoplastic. Thus, only a portion of the waste material used for downstream binder manufacturing purposes may be functionalized, which has been found to have beneficial effects in terms of processing speed and efficiency, as well as the cost of the functionalizing agent.

[0203] The functionalized thermoplastics processed in the emulsification zone of the extruder or TSE can be prepared by the first module of the extruder or TSE melting and functionalizing the thermoplastic.

[0204] Some or all of the functionalized thermoplastic can be derived from commercially available compatibilized thermoplastics, such as compatibilized PE functionalized with maleic anhydride, etc. Examples 6 and 10 demonstrate the preparation of composite boards containing functionalized thermoplastics.

[0205] A commercially available compatibilized thermoplastic can be mixed with a non-functionalized thermoplastic processed in the first module (melt zone), a functionalized thermoplastic processed in the first module (melt zone containing one or more coupling agents), or a combination thereof, and then emulsified.

[0206] A dispersant may be added to promote the formation of a stable dispersion or emulsion. In selected embodiments, the dispersant may be a surfactant, a polymer, or a mixture thereof. In certain embodiments, the polymer may be a polar polymer having a polar group as either a comonomer or a grafted monomer. In a preferred embodiment, the dispersant may include a stabilizer comprising one or more polar polyolefins having a polar group as either a comonomer or a grafted monomer.

[0207] The dispersant may comprise at least one carboxylic acid, at least one salt of a carboxylic acid, or a carboxylic acid ester or salt of a carboxylic acid ester. The carboxylic acid, salt of a carboxylic acid, or the carboxylic acid moiety of the carboxylic acid ester or salt of such an ester may have up to 60, or up to 50, or up to 40, or up to 30, or up to 25 carbon atoms. The carboxylic acid, salt of a carboxylic acid, or the carboxylic acid moiety of the carboxylic acid ester or salt of such an ester may have at least 12, or at least 15, or at least 20, or at least 25 carbon atoms. When in salt form, the dispersant comprises a cation selected from the group consisting of an alkali metal cation, an alkaline earth metal cation, or an ammonium or alkylammonium cation. The dispersant may be an olefin (e.g., ethylene) carboxylic acid polymer, or a salt thereof, such as an ethylene acrylic acid copolymer or an ethylene methacrylic acid copolymer.

[0208] For example, the dispersant can include an ethylene / α-β unsaturated carboxylic acid copolymer. In some embodiments, the ethylene / α-β unsaturated carboxylic acid copolymer can include an ethylene-acid copolymer, such as an ethylene-acrylic acid copolymer or an ethylene-methacrylic acid copolymer. Typical copolymers include ethylene-acrylic acid (EAA) copolymers and ethylene-methacrylic acid copolymers, such as those available under the trademarks PRIMACOR™ (a trademark of The Dow Chemical Company), NUCREL™ (a trademark of EI DuPont de Nemours), and ESCOR™ (a trademark of ExxonMobil). Other copolymers include ethylene ethyl acrylate (EEA) copolymer, ethylene methyl methacrylate (EMMA), and ethylene butyl acrylate (EBA). Other ethylene-carboxylic acid copolymers can also be used.

[0209] Alternatively, the dispersant may be selected from alkyl ether carboxylates, petroleum sulfonates, sulfonated polyoxyethylenated alcohols, sulfated or phosphated polyoxyethylenated alcohols, polymeric ethylene oxide / propylene oxide dispersants, primary and secondary alcohol ethoxylates, alkyl glycosides, and alkyl glycerides.

[0210] Combinations of the above dispersants may also be used.

[0211] For certain dispersants or compatibilizers, it may be desirable to include a neutralizing agent to improve the effectiveness of the dispersant. For example, if the polar groups of the thermoplastic polymer are acidic or basic, the dispersant can be partially or fully neutralized with a neutralizing agent to form the corresponding salt. In certain embodiments, the neutralization of a dispersant, such as a long-chain fatty acid or EAA, can be 25% to 200% on a molar basis, and in other embodiments, can range from 50% to 110% on a molar basis. For example, for EAA, the neutralizing agent is a base, such as ammonium hydroxide or potassium hydroxide. Other neutralizing agents can include, for example, lithium hydroxide or sodium hydroxide. Those skilled in the art will understand that the selection of an appropriate neutralizing agent depends on the specific composition being formulated, and such a selection is within the knowledge of those skilled in the art.

[0212] Described herein are methods for forming plastic-containing polymer-water dispersions, optionally emulsions. The dispersions can be formed in one or more extruders, such as single-screw or twin-screw extruders (TSEs). The single-screw or twin-screw extruders include a housing having an inlet end and an outlet end and one or two rotating screws disposed within the housing between the inlet and outlet ends. A thermoplastic is introduced into the inlet end of the one or more single-screw or twin-screw extruders. The one or more single-screw or twin-screw extruders sufficiently melt the thermoplastic to form a melt zone. In one example, at least a portion of the thermoplastic is reacted with a coupling agent selected from at least one of a grafted compatibilizer, a reactive hydrogen donor, and a functionalizing agent to form a functionalized thermoplastic.

[0213] Particle size reduction in extruders is achieved by capillary rupture. The melt zone contains molten polymer. This can be followed by a molten polymer seal. Past the seal, water and optional surfactants are present and undergo high shear mixing to produce metastable particles called striata (fine fibers). The energy required to reduce particle size using these methods is much lower than standard particle size reduction techniques.

[0214] In some embodiments, at least 10% by weight of the thermoplastic may be functionalized. Another portion, comprising up to 90% by weight of the thermoplastic, may be unfunctionalized. Other ratios of functionalized and unfunctionalized material may be used. The degree of functionalization of the functionalized thermoplastic portion may vary depending on the reaction conditions and availability of reactants. In some embodiments, the degree of functionalization of the thermoplastic polymer in the functionalized thermoplastic portion may range from 0.5% to 6%, as previously described.

[0215] A twin-screw extruder (TSE) consists of two screws attached to a barrel with a "figure-eight" cross section. The "figure-eight" cross section is derived from machining two cylindrical holes with centers less than two radii apart. Twin-screw extruders typically use segmented screws attached to high-torque splined shafts or solid screws machined from round bar stock. The barrel of a TSE may be modular. TSEs may also use liquid cooling. The TSE motor inputs energy into the process through the rotating screws. A feeder meters material into the TSE. The screw speed can be set to optimize processing efficiency because it can be independent of other process conditions. Segmented screws and barrels, combined with the controlled pumping and wiping characteristics of co-rotating screws, allow the screw / barrel geometry to be tailored to the process task.

[0216] The TSE or other extruder may be modular, with a first module containing at least the melt zone of the TSE or other extruder and a second module containing at least the emulsification zone of the TSE or other extruder.

[0217] As shown in FIG. 5A, in a single, non-modular twin-screw extruder, thermoplastic 7 proceeds directly from inlet 3 to outlet 4, passing through various zones of the TSE, such as melting zone 5 and emulsification zone 6. Similar zones and modes of operation are found in other extruders, and references to twin-screw extruders herein may refer to these. In one example, all of the extruded thermoplastic undergoes a functionalization reaction to make the thermoplastics compatible. Those skilled in the art will understand that this does not mean that all of the thermoplastic polymer groups are actually functionalized. In many cases, only a small percentage of the groups, e.g., 0.5% to 6%, are functionalized. There are various reasons why not all of the polymer's functional groups are functionalized, including blocking of the functional groups by other chemical moieties, incomplete melting, mixing, or atomization of the thermoplastic.

[0218] In some cases, it may be desirable to provide an emulsion containing a blend of micronized functionalized thermoplastics and micronized non-functionalized thermoplastics. In some cases, micronization can be achieved in the extruder and does not need to be performed as a pretreatment step. One way to accomplish this is to batch process the thermoplastics in a single modular or non-modular extruder, with one batch 8 containing one or more coupling and / or crosslinking agents and a second batch 9 containing no coupling or crosslinking agents. The two resulting thermoplastic dispersions or emulsions can then be mixed to form a composite thermoplastic dispersion or emulsion containing the desired blend of functionalized and non-functionalized micronized thermoplastics. Alternatively, as shown in FIG. 5B, the functionalized thermoplastic 8 and the non-functionalized thermoplastic 9 can be batched separately in a single melt zone 5 and then passed through the extruder / TSE emulsification zone 6 to produce emulsion 17.

[0219] Alternatively, an extruder / TSE module, or a combination of extruder or TSE, can be used. For example, as shown in FIG. 5C, the method can include multiple first modules (51 and 52) containing melt zones. The thermoplastic in one melt zone module 51 can react with one or more coupling agents, while the thermoplastic in the second melt zone module 52 cannot react with the coupling agents. The molten thermoplastics from both modules are fed to a second module 6 (i.e., an emulsification module) to provide a thermoplastic dispersion or emulsion 17 containing a mixture of functionalized and non-functionalized thermoplastics.

[0220] Alternatively, as shown in Figure 5D, thermoplastic 7 can be fed into an extruder / TSE module having a melting zone 5 and reacted with one or more coupling agents to produce a molten functionalized thermoplastic 8. The molten functionalized thermoplastic 8 can then be fed, along with unmolten, unfunctionalized thermoplastic 1, into a second module including an emulsification zone 6.

[0221] The functionalized molten thermoplastic can be emulsified in an emulsification zone of a twin-screw extruder by subjecting the functionalized molten thermoplastic to water, surfactant, and sufficient shear to form a functionalized thermoplastic having an average particle size (Dv50) of less than 0.5 mm to produce a dispersion or emulsion of the functionalized thermoplastic in which water is the continuous phase. The functionalized thermoplastic dispersion or emulsion is then extruded from one exit end of one or more twin-screw extruders, the emulsion comprising functionalized plastic particles having an average particle size (Dv50) of less than 0.5 mm.

[0222] Example 11 provides examples of making wood fiber boards from various recycled thermoplastic feedstocks.

[0223] The method may further include adding a crosslinking agent in liquid form, and optionally water, to the functionalized thermoplastic emulsion in one or more extruders or a twin-screw extruder at a temperature insufficient to chemically activate the crosslinking agent.

[0224] The thermoplastic dispersion / emulsion resulting from the emulsification / TSE process can be used as a binder, which can then be mixed with lignocellulosic fibers to form a composite mixture and placed in a press to apply heat and pressure to the composite mixture to form a lignocellulosic-thermoplastic composite.

[0225] The extruder or twin screw extruder may be modular, i.e., a first module may include a twin screw extruder melt zone that includes the addition of a coupling agent, and a second module may include an extruder or twin screw extruder emulsification zone that includes the addition of at least water and surfactant.

[0226] In one example shown in Figures 7a-e, the extruder is equipped with zones suited to specific processing steps.

[0227] TSE Zone An extruder or TSE is composed of different zones that process thermoplastics. In one example, the transport and melting of the thermoplastic occurs in the first section of the extruder or TSE, called the "melt zone." The melt zone may also include a zone for functionalizing the thermoplastic, located downstream of where the thermoplastic melts. The functionalization zone includes at least the addition of one or more coupling agents to functionalize the thermoplastic, so that the coupling agents functionalize the thermoplastic after it melts. The coupling agent may be mixed with the thermoplastic before it is fed into the extruder or TSE, or it may be added to the extruder or TSE through an inlet during or after the thermoplastic melts in the melt zone.

[0228] 7a-7e illustrate an example of processing a thermoplastic 7 in an extruder. In FIG. 7a, the thermoplastic 7 is fed into the extruder via feeder 3 and passes through melting zone 5 to provide a molten thermoplastic 8. The molten thermoplastic proceeds to functionalization zone 5A, where it is mixed with a coupling agent. This coupling agent may be injected through inlet 5Ai or may be added simultaneously or sequentially with the thermoplastic 7 via feeder 3. In one example, functionalization zone 5A is controlled to provide an optimal temperature for functionalizing the thermoplastic. The functionalized thermoplastic then enters mixing zone 5B, where it is mixed before being extruded through outlet 4 to provide the functionalized thermoplastic. The functionalized thermoplastic can then be passed through another extruder and emulsified to provide a thermoplastic dispersion.

[0229] In a further example shown in Figure 7b, the mixing zone of 7a can be replaced by or combined with emulsification zone 6. In this example, water and optional surfactant are injected through inlet 6Ai and mixed throughout the emulsification zone to provide a functionalized thermoplastic dispersion that is extruded through outlet 4.

[0230] In a further example shown in Figure 7c, the thermoplastic passes through melting zone 5 and proceeds to emulsification zone 6. In this example, water and optional surfactant are injected through inlet 6Ai and mixed throughout the emulsification zone to provide a thermoplastic dispersion that is extruded through outlet 4.

[0231] In a further example shown in Figure 7d, the thermoplastics pass through melting zone 5 and into mixing zone 5B where they are mixed. In this example, water and optional surfactant are injected through inlet 6Ai and mixed throughout emulsification zone 6 to provide a thermoplastic dispersion that is extruded through outlet 4.

[0232] In one example, the extrusion process described in Figure 7d is performed after the process described in Figure 7a.

[0233] The extruder may include multiple mixing zones and injection zones.

[0234] In a further example shown in FIG. 7e, thermoplastic 7 is fed into the extruder via feeder 3 and proceeds through melting zone 5 8 to provide a molten thermoplastic. The molten thermoplastic proceeds to functionalization zone 5A, where it is mixed with a coupling agent. This coupling agent may be injected through inlet 5Ai or added simultaneously or sequentially with thermoplastic 7 via feeder 3. In one example, functionalization zone 5A is controlled to provide an optimal temperature for functionalizing the thermoplastic. The functionalized thermoplastic then enters mixing zone 5B, where it is mixed before being sent to emulsification zone 6. Water and optional surfactant are injected through inlet 6Ai and mixed throughout the emulsification zone to provide a dispersion of functionalized thermoplastic. This dispersion may be sent to a further mixing zone (not shown) or conveying zone (not shown) before being extruded through outlet 4.

[0235] The sequential combination of the melting zone, mixing zone, and emulsification zone provides particularly effective size reduction and dispersion preparation. This is believed to be due to the placement of inlet 6Ai after the mixing zone. The effect of inlet 6Ai is a temperature reduction due to the addition of liquids (i.e., water and surfactant) that are significantly cooler than the molten material. Without effective melting and mixing prior to inlet 6Ai, it is believed that the material would not be sufficiently reduced in size or mixed.

[0236] The temperature configuration of the extruder may vary depending on the reaction requirements. The melt zone is defined as a zone requiring a temperature setpoint higher than the melt temperature of the thermoplastic being processed. This temperature may be above 130°C for LDPE and 160-220°C for PP. The mixing zone is configured at a temperature approximately equal to the melt temperature to maintain the thermoplastic in a molten state. After the mixing zone, an optional vent zone is provided to evaporate unreacted monomers and purify the thermoplastic output. The temperature of the vent zone is set to allow for volatilization of the coupling agent and may be up to 20°C higher than the melt zone, e.g., above 200°C. Before exiting the extruder, the temperature may be reduced to reduce the viscosity of the extruded material.

[0237] The above definitions of the zones will be clear to those skilled in the art. However, as an example, the melt zone is a zone of the extruder having a temperature setpoint that achieves substantially complete melting of the polymeric raw materials. The melt zone can be formed by an aggressive melt zone design. For example, neutral / wide kneading block elements are used. Reverse elements may also be used in the melt zone. The reverse elements can achieve complete melting of the thermoplastic polymer. Alternatively, the melt zone can be formed by an expansion screw design using narrow disc kneading block elements. The narrow disc kneading block elements reduce the concentrated input of shear stress to the thermoplastic polymer, resulting in a more gradual melting of the polymer.

[0238] The screw elements of the extruder are selected to perform different unit operations as the ingredients pass along the length of the screw. One example includes an initial melting zone, followed by a mixing / conveying zone, then an emulsification zone, and finally a dilution / cooling zone. Vapor pressure at the feed end is reduced by placing kneading blocks and blister elements between the melt-mixing zones and is also reduced and controlled by the use of backpressure regulators. The polyolefin, dispersant, compatibilizer, and water are melt-kneaded within the extruder.

[0239] The melt zone can be heated to about 140°C to about 240°C, or to any temperature necessary to melt the thermoplastic in the melt zone. For some low melting point thermoplastics, the melt zone can be set at 95°C to 140°C. During start-up, the extruder temperature is increased to a set point higher than the operating temperature. In one example, the start-up temperature is increased to at least about 150°C. In another example, where the thermoplastic has a higher melting temperature, the temperature is increased to about 180°C.

[0240] The melt zone may use an external heating element to heat the melt zone. It will be understood that when the extruder or TSE starts up, the extruder or TSE includes a heat input (such as a heating element or heating jacket). However, if the extruder or TSE runs for a sufficient period of time, the extruder or TSE will generate heat due to friction. As the frictional heat increases, the external heat input may be reduced (or even eliminated) to prevent overheating. Overheating can result in degradation of the thermoplastic, as indicated by smoke and discoloration. The extruder or TSE may include a cooling element in the melt zone to prevent overheating. The cooling element may be in the form of a cooling passage. A cooling liquid, such as water, may be passed through the cooling passage to cool the extruder or TSE.

[0241] During operation, the extruder or twin screw extruder is maintained at a set temperature for the zone along the barrel. In one example, the barrel is equipped with one or more water-cooled zones.

[0242] The barrel temperature setpoint may be automatically adjusted to maintain it at or near the barrel zone temperature setpoint. This automatic feedback mechanism is achieved using a temperature control device, which senses the temperature using a temperature sensor located in or near the barrel and then sends the data to a temperature controller. The controller adjusts the temperature using a portion of the temperature control device based on the barrel zone temperature setpoint. The temperature can be adjusted by a water chiller adjusted to cool the barrel. The temperature can be adjusted by a heating element adjusted to heat the barrel.

[0243] There may be multiple extruder zones, each equipped with a temperature control device. Example 2.1 discusses initial experiments using waste polymer, which showed that to achieve effective emulsification of the waste polymer, it is preferable to set the extruder temperature setpoint higher, e.g., 20% higher, than the melt temperature of the polymer being processed.

[0244] The melt zone is free or substantially free of water. The presence of water may interfere with the activity of any coupling agents that may be present. The melt zone may contain less than 5%, less than 4%, less than 3%, less than 2%, or less than 1% water by weight of the thermoplastic, with suitable ranges selected between any of these values.

[0245] After passing through the melt zone, the thermoplastic is processed in another section of the extruder or TSE. In one example, the next zone comprises a mixing zone. The mixing zone can comprise kneading and mixing elements.

[0246] The examples provided herein also include an emulsification zone, which includes the addition of water and optional surfactant.

[0247] Upon entering the emulsification zone of the extruder or TSE, water and an optional surfactant are added to the thermoplastic, which may be functionalized. Upon addition of water and surfactant, the thermoplastic may form a bicontinuous phase in the first section of the emulsification zone. The bicontinuous phase is an interphase between a water-in-oil and an oil-in-water mixture. The bicontinuous phase may also be an interphase between a water-in-polymer and a polymer-in-water mixture. Upon further addition of water to the emulsification zone, the emulsion forms a water-continuous emulsion.

[0248] The emulsion is formed in the emulsification zone of the extruder or TSE under shear forces provided by the extruder design, for example, by a screw in the emulsification zone of the extruder or TSE that imparts shear forces (or shear stress).

[0249] The emulsification zone may include a water mixing zone, where water and surfactant are initially mixed, and a shear zone, which applies shear forces downstream of the water mixing zone. In one example, the water (and optional surfactant) mixing zone and the shear zone are combined to form a dispersion zone. The dispersion zone precedes the dilution zone.

[0250] The emulsification zone may include a dilution zone with a port for adding additional water. That is, an initial amount of water is added, optionally with a surfactant, before the mixing zone. As the material moves downstream of the water mixing zone, additional water is injected in the dilution zone. The additional water may be where the bicontinuous phase changes to an oil-in-water phase or a polymer-in-water phase (with water as the continuous phase).

[0251] The surfactant can be blended into the feed mixture before it enters the extruder, which is particularly effective when using a solid surfactant such as PVOH, or the surfactant can be injected into the extruder at a location downstream of the feed, preferably downstream of the melt zone.

[0252] Water can be injected through a water inlet, such as 6Ai, and optionally additional inlets, i.e., a water injection line terminating in the inlet, which can include a flow meter and a valve to control the amount of water added to the extruder or TSE.

[0253] The water flow rate can be adjusted to achieve a desired water content for the thermoplastic dispersion being produced. The amount is scale-dependent and typically expressed as a resin:water ratio (w / v). In the methods described herein, the resin comprises a thermoplastic. In some embodiments, the resin:water ratio ranges from 1:1 to 5:1. The resin:water ratio in the post-mix zone can be between 2:1 and 5:1. This allows for the water to be fed while maintaining a high resin throughput during the particle breakage stage. The water input to the dilution zone can be adjusted to achieve a resin:water ratio in the dilution zone of about 0.8:1 to 1.8:1. Increasing the amount of water added to the dilution zone, optionally in combination with a surfactant, disperses the particles to form a thermoplastic dispersion.

[0254] The plastic-to-water ratio can be adjusted to achieve a target moisture content for the thermoplastic dispersion. Moisture content is a critical parameter in the production of composite boards, such as lignocellulosic composite boards, because too much moisture can weaken the board. Similarly, too little moisture can impair the ability of certain crosslinkers to effectively bond to the lignocellulosic material.

[0255] The moisture content of the thermoplastic dispersion may be between 25 and 75%. The moisture content can be adjusted to ensure that the moisture content of the board made using the thermoplastic dispersion is within the desired range. Thus, the moisture content of the thermoplastic dispersion is preferably in the range of 35% to 55%. The moisture content of the dispersion can be adjusted, for example, by dilution in a dilution zone of the extruder. Alternatively, it can be further adjusted by drying after extrusion. Achieving a specific desired moisture content reduces the need for drying the dispersion, with corresponding benefits in reduced energy use and preparation time. In this example, the moisture content of the thermoplastic dispersion is approximately 40 to 50%.

[0256] The water injection system may be a high-pressure, low-volume system. For example, the system may include an injector, which may be based on a spring-loaded ball mounted in the inlet chamber of the extruder, a manifold, and a pump. The manifold may include a gate valve, a regulating needle valve, and a flow meter.

[0257] The inventors have found that the properties of the thermoplastic dispersion obtained after emulsification can affect the properties of materials made with binders that include the thermoplastic dispersion, particularly properties including particle size, particle size distribution, and melt flow index.

[0258] Additionally, the properties of the thermoplastic introduced into the extruder also affect the properties of the thermoplastic dispersion produced after emulsification. The inventors have found that using a thermoplastic with a higher melt flow index results in a thermoplastic dispersion with smaller particle size. The smaller the particle size, the easier it is to mix with the lignocellulosic material to form a composite panel. Furthermore, the smaller the particle size, the better the integration of the binder with the lignocellulosic material.

[0259] A method is described for treating a thermoplastic to increase its melt flow index, followed by steps to produce a thermoplastic dispersion and, optionally, a board. The dispersion and board are produced according to the methods described herein. A thermoplastic dispersion with a higher melt flow index can be correlated with a smaller particle size and a smaller particle size distribution.

[0260] The crosslinking agent is added prior to the production of the composite board. The crosslinking agent can be added in the extruder / TSE, in the extruded thermoplastic dispersion / emulsion, or in both the extruder / TSE and the extruded emulsion.

[0261] The crosslinker can be selected from a participatory crosslinker or a non-participatory crosslinker. A participatory crosslinker is a crosslinker that directly participates in the bond between the two compounds being linked. That is, one end of the participatory crosslinker forms a bond with one compound, and the other end of the participatory crosslinker forms a bond with the other compound.

[0262] A non-participating crosslinker is a crosslinker that does not directly participate in the bonding between two compounds; i.e., it does not form a bond with the two compounds being linked. Instead, a non-participating crosslinker interacts with one or more compounds to provide an active site on at least one compound. This active site then provides a site for bonding between the two compounds.

[0263] The temperature of the extruder or TSE can be changed before or during the addition of the participatory crosslinker. The temperature of the extruder / TSE can be reduced by a water-based cooling system such as a high-pressure water cooling system, barrel cooling, or a water jacket. The temperature of the extruder / TSE can be reduced by adding water. The temperature of the extruder / TSE can be reduced by a combination of both adding water and an active cooling system.

[0264] The participative crosslinker may be an isocyanate. Without wishing to be bound by theory, it is believed that the addition of an isocyanate also has the effect of reducing the hydrophilicity of the lignocellulosic fibers / materials.

[0265] The temperature of the extruder / TSE may be changed before or during the addition of the non-participating crosslinker. The temperature of the extruder / TSE can be reduced by a water-based cooling system such as a high-pressure water cooling system, barrel cooling, or a water jacket. The temperature of the extruder / TSE can be reduced by adding water. The temperature of the extruder / TSE can be reduced by a combination of both adding water and using an active cooling system.

[0266] The non-participative crosslinker may be an organic peroxide.

[0267] When a non-participating crosslinking agent such as an organic peroxide is added, it can be added at about 0.1%, 0.5%, 1%, 2%, 3%, 4%, or 5% by weight of the thermoplastic dispersion / emulsion, and a suitable range can be selected between any of these values. The non-participating crosslinking agent such as an organic peroxide may be added when the grafted compatibilizer or reactive hydrogen donor is added.

[0268] Example 6 demonstrates the preparation of wood fiber composite boards using an organic peroxide crosslinker. Specifically, 1,1-di-(tert-butylperoxy)-3,3,5-trimethylcyclohexane improved the strength of wood fiber composite boards prepared using a thermoplastic dispersion of LDPE in water. The organic peroxide crosslinker can be added to the thermoplastic dispersion to form a binder containing 1-10% organic peroxide to improve strength. In some embodiments where lower strength may be acceptable, the organic peroxide crosslinker is added at 2-8%.

[0269] As stated, the binder may include the following components: Organic peroxides (e.g. luprox) 3-5% MAPE 10-20% Thermoplastic dispersion 75-87%

[0270] As stated, the composite board of the present invention may be comprised of the following composition (w / w): Lignocellulosic materials (e.g. wood fibers) 95% Thermoplastic dispersion 4% MAPE 0.75% Organic peroxides (e.g. luprox) 0.25%

[0271] The organic peroxide can be supplied in powder or liquid form. Experiments conducted by the inventors have shown that the powder form is easier to mix. The powdered organic peroxide can contain 40% benzoyl peroxide.

[0272] If a participating crosslinker such as an isocyanate is added, it may be added at about 0.1%, 0.5%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, or 15% by weight of the thermoplastic dispersion / emulsion, with suitable ranges selected between any of these values. (For example, about 0.1% by weight to about 15% by weight, about 0.1% by weight to about 13% by weight, about 0.1% by weight to about 10% by weight, about 0.1% by weight to about 8% by weight, about 0.1% by weight to about 5% by weight, about 0.5% by weight to about 20% by weight, about 0.5% by weight to about 19% by weight, about 0.5% by weight to about 17% by weight, about 0.5% by weight to about 12% by weight, about 0.5% by weight to about 9% by weight, about 0.5% to about 5% by weight, about 1% to about 20% by weight, about 1% to about 18% by weight, about 1% to about 16% by weight, about 1% to about 14% by weight, about 1% to about 10% by weight, about 2% to about 20% by weight %, about 2% to about 18% by weight, about 2% to about 16% by weight, about 2% to about 14% by weight, about 2% to about 10% by weight, about 3% to about 20% by weight, about 3% to about 17% by weight, about 3% to about 1 5% by weight, about 3% to about 11% by weight, about 3% to about 9% by weight, about 4% to about 20% by weight, about 4% to about 18% by weight, about 4% to about 16% by weight, about 4% to about 10% by weight, about 5% by weight ~20% by weight, approximately 5% by weight ~ approximately 18% by weight, approximately 5% by weight ~ approximately 17% by weight, approximately 5% by weight ~ approximately 11% by weight, approximately 6% by weight ~ approximately 20% by weight, approximately 6% by weight ~ approximately 18% by weight, approximately 6% by weight ~ approximately 16% by weight, approximately 6 Weight% to about 12% by weight, about 6% to about 10% by weight, about 7% to about 20% by weight, about 7% to about 18% by weight, about 7% to about 15% by weight, about 7% to about 12% by weight, about 7% to about 10% by weight %, about 8% to about 20% by weight, about 8% to about 17% by weight, about 8% to about 15% by weight, about 8% to about 13% by weight, about 8% to about 10% by weight, about 9% to about 20% by weight, about 9% to about 1 6% by weight, about 9% to about 13% by weight, about 10% to about 20% by weight, about 10% to about 16% by weight, about 11% to about 20% by weight, about 11% to about 17% by weight, about 12% to about 20% by weight, about 12% to about 17% by weight, about 13% to about 20% by weight, about 13% to about 18% by weight, about 14% to about 20% by weight, about 14% to about 18% by weight, or about 15% to about 20% by weight. When a reactive hydrogen donor is added as a coupling agent, a participating crosslinking agent such as isocyanate can be added.

[0273] The inventors have derived a preferred stoichiometric ratio of isocyanate to thermoplastic dispersion that achieves effective reaction rate and composite board strength. As a result, the binder can contain 5-20% isocyanate. In other words, the isocyanate is added at 5-20% by weight of the binder. In one specific example, the composite board can be comprised of the following composition (w / w): · lignocellulosic materials (e.g. wood fibers) 90%; · Thermoplastic dispersion 9%; · eMDI 1%;

[0274] Another composite board composition may include: · Lignocellulosic materials 90%; · Thermoplastic dispersion 8%; · eMDI 2%.

[0275] Another composite board composition may include: · Lignocellulosic materials 90%; · Thermoplastic dispersion 9.5%; · eMDI 0.5%.

[0276] Example 12 provides various additional examples of the composite board compositions described.

[0277] Without wishing to be bound by theory, it is believed that isocyanates react with natural fibers to change their polarity. Urethane bonds are formed between the isocyanate functional groups and the hydroxyl groups of the natural fibers, which can block the hydrophilic hydroxyl sites, thereby reducing the hydrophilicity of the wood fibers and improving their compatibility with hydrophobic thermoplastics. As mentioned above, the use of diisocyanates allows for the formation of bonds with reactive sites on the functionalized polymer. One isocyanate group of the diisocyanate can react with the hydroxyl groups of the wood fibers, while the other isocyanate group reacts with the reactive sites on the functionalized polymer. This allows for the formation of covalent bonds between the reactive sites on the functionalized polymer and the diisocyanate.

[0278] Isocyanates can also react with other hydroxyl groups on lignocellulosic fibers, such as wood fibers, masking their hydrophobicity. In this case, diisocyanates can be used to block polar, hydrophobic hydroxyl groups on the fibers or to form covalent bonds with reactive sites on functionalized polymers, thereby increasing the compatibility of plastic polymers with wood fibers.

[0279] Emulsified isocyanate compounds, such as emulsified methylene diphenyl diisocyanate (eMDI), can be used as crosslinkers in combination with thermoplastic dispersions to produce composite boards. Example 5 demonstrates that when an isocyanate is combined with a thermoplastic dispersion (e.g., one prepared according to the methods described herein), eMDI achieves superior mixing properties and enhanced strength compared to pMDI.

[0280] Binder Compound Thermoplastic dispersions can be formulated as binders by mixing the dispersion with one or more crosslinkers, as detailed above. To form a composite board, the binder is then mixed with the lignocellulosic material. The binder can comprise 1% to 50% of the composite mixture. However, providing more than 20% binder in the board can compromise board properties by reducing the fiber content, which provides a physical matrix that improves strength.

[0281] Thus, the binder formulation can comprise 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, or 20% by weight of the composite board, and suitable ranges can be selected between any of these values ​​(e.g., about 1% to about 20% by weight of the composite board, about 1% to about 18% by weight, about 1% to about 20% by weight of the composite board ... % to about 16% by weight, about 1% to about 14% by weight, about 1% to about 10% by weight, about 2% to about 20% by weight, about 2% to about 18% by weight, about 2% to about 16% by weight, about 2% to about 14% by weight, about 2% to about 10% by weight, about 3% to about 20% Amount%, about 3% to about 17% by weight, about 3% to about 15% by weight, about 3% to about 11% by weight, about 3% to about 9% by weight, about 4% to about 20% by weight, about 4% to about 18% by weight, about 4% to about 16% by weight, about 4% to about 10% by weight, about 5% by weight % to about 20% by weight, about 5% to about 18% by weight, about 5% to about 17% by weight, about 5% to about 11% by weight, about 6% to about 20% by weight, about 6% to about 18% by weight, about 6% to about 16% by weight, about 6% to about 12% by weight, about 6% to about 10 Weight%, about 7% to about 20% by weight, about 7% to about 18% by weight, about 7% to about 15% by weight, about 7% to about 12% by weight, about 7% to about 10% by weight, about 8% to about 20% by weight, about 8% to about 17% by weight, about 8% to about 15% by weight, about 8 The binder content may be in the range of about 13% to about 13% by weight, about 8% to about 10% by weight, about 9% to about 20% by weight, about 9% to about 16% by weight, about 9% to about 13% by weight, about 10% to about 20% by weight, about 10% to about 16% by weight, about 11% to about 20% by weight, about 11% to about 17% by weight, about 12% to about 20% by weight, about 12% to about 17% by weight, about 13% to about 20% by weight, about 13% to about 18% by weight, about 14% to about 20% by weight, about 14% to about 18% by weight, or about 15% to about 20% by weight. If the formulation contains too little binder, the lignocellulosic particles will not be sufficiently coated to form effective bonds between the particles, which can cause the board to fall apart under load.Thus, the lignocellulosic material:binder ratio can range from about 80% lignocellulosic material:20% binder to 95% lignocellulosic material:5% binder. In another example, the lignocellulosic material:binder ratio can range from about 85% lignocellulosic material:15% binder to 92% lignocellulosic material:8% binder.

[0282] Example 12 shows that composite boards with less lignocellulosic material swell less and are therefore more suitable for outdoor or humid environments. Thus, for boards that swell less than 20% in 24 hours, the lignocellulosic material:binder ratio ranges from about 90:10 to 85:15.

[0283] Composite boards can be designed to achieve specific minimum strength standards. Example 12 shows exemplary binder compositions containing varying levels of crosslinker, thermoplastic dispersion, and lignocellulosic material. Composite boards made using thermoplastic dispersions prepared according to the methods described herein have a modulus of elasticity of at least 1000 MPa, as measured according to ASTM D1037 or EN310. This results in boards suitable for lightweight applications. In other examples where higher strength boards are required, the composite boards can have MoEs of greater than 1200, 1400, or 1600, depending on the end-use requirements. Examples 15 and 16 show examples of composite boards meeting these strength requirements with varying levels of crosslinker. In some examples, the binder contains 85-94% thermoplastic dispersion and 6-15% crosslinker. When composite boards are made according to the methods described herein, the binder can comprise approximately 5-20% of the composite mix used to make the composite board, with the remainder consisting of lignocellulosic material. In another example, the binder comprises approximately 8-15% of the composite mixture, with the remainder being comprised of lignocellulosic materials such as wood chips.

[0284] Mixing of the binder with the appropriate lignocellulosic material can be accomplished in a variety of ways, including paddle mixing, tumbling, and / or spraying the binder during mixing. The preparation of the thermoplastic dispersions described herein improves mixability and the properties of the resulting board compared to simply mixing a reduced-size thermoplastic with a crosslinker and a lignocellulosic substrate.

[0285] Isocyanates are highly reactive compounds. Blocking agents can be used to control reactivity by blocking the isocyanate functionality to form blocked isocyanates. However, blocking may not be necessary if the isocyanate is added to the emulsion immediately prior to mixing with the lignocellulosic material to form the thermoplastic composite product.

[0286] When a blocked isocyanate is heated to a certain temperature, the blocking agent separates from the isocyanate, thereby restoring the isocyanate functionality. The blocking agent allows the components to be mixed without reacting the isocyanate. If it is desired to restore the isocyanate functionality, the components can be heated to react the isocyanate. The isocyanate functionality can be blocked until the waste plastic has sufficiently wetted the wood chips. This prevents the isocyanate from reacting with water before the plastic melts. The use of a blocking agent creates a compound that is seemingly inactive at room temperature but generates reactive isocyanate functionality at elevated temperatures.

[0287] Examples of blocking agents include phenol, cardanol, cresol, xylenol, nitrophenol, ethylphenol, hydroxydiphenyl, butylphenol, isopropylphenol, nonylphenol, octylphenol, methyl hydroxybenzoate, and similar phenolic compounds; ε-caprolactam, δ-valerolactam, γ-butyrolactam, β-propiolactam, and similar lactam compounds; methanol, ethanol, propyl alcohol, butyl alcohol, amyl alcohol, lauryl alcohol, and similar aliphatic alcohol compounds; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol monomethyl ether, methoxymethanol, and similar ether compounds; benzyl alcohol; glycolic acid; methyl glycolate, ethyl glycolate, butyl glycolate, and similar glycolic acid esters; lactic acid, methyl lactate, milk, and similar ether compounds. ethyl lactate, butyl lactate, and similar lactic acid esters; methylol urea, methylol melamine, diacetone alcohol, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, and similar alcohol compounds; formamide oxime, acetamide oxime, acetoxime, methyl ethyl ketoxime, diacetyl monooxime, benzophenone oxime, cyclohexane oxime, and similar oxime compounds; dimethyl malonate, diethyl malonate, ethyl acetoacetate, methyl acetoacetate, acetylacetone, and similar active methylene compounds; butyl mercaptan, t-butyl mercaptan, hexyl mercaptan, t-dodecyl mercaptan, 2-mercaptobenzothiazole, thiophenol, methylthiophenol, ethylthiophenol, and similar mercaptan compounds; acetanilide, acetanisidide, acetotoluide, acrylamide, methacrylamide, acetic amide, stearic amide, benzamide, and similar acid amide compounds; succinimide, phthalimide, maleimide, and similar imide compounds;Examples of suitable functionalizing agents include diphenylamine, phenylnaphthylamine, xylidine, N-phenylxylidine, carbazole, aniline, naphthylamine, butylamine, dibutylamine, butylphenylamine, and similar amines; imidazole, 2-ethylimidazole, and similar imidazole compounds; 3,5-dimethylpyrazole and similar pyrazole compounds; urea, thiourea, ethyleneurea, ethylenethiourea, diphenylurea, and similar urea compounds; phenyl N-phenylcarbamate and similar carbamate compounds; ethyleneimine, propyleneimine, and similar imine compounds; and sodium bisulfite, potassium bisulfite, and similar sulfite compounds. In some embodiments, crosslinking agents such as isocyanates and organic peroxides can be added to the functionalized plastic emulsion immediately before adding the lignocellulosic substrate / material.

[0288] The temperature of the extruder or TSE when the blocked isocyanate is added must be reduced to below the unblocking temperature of the isocyanate, for example, by adding water and / or using cooling channels in the extruder / TSE. A table showing the unblocking temperatures of various isocyanate blocking agents is provided below.

[0289] [Table 1]

[0290] The crosslinking agent can be added in powder form or other solid form. The crosslinking agent is typically added to the TSE in liquid form, i.e., dissolved in water, since small amounts are added to the extruder / TSE.

[0291] After addition of the cross-linking agent, additional water may be added to the TSE.

[0292] If the crosslinking agent is a non-participating crosslinking agent, such as an organic peroxide, the emulsion may be dried to a moisture content of less than about 3% by weight.

[0293] When the crosslinker is a participatory crosslinker such as an isocyanate, drying may not be necessary. That is, isocyanates have higher water resistance than organic peroxide-based crosslinkers. The presence of a high amount of water may be advantageous in terms of heat transfer during the board manufacturing process. The isocyanate-containing emulsion may have a solids content of approximately 30%, 40%, 50%, 60%, or 70% by weight, with a suitable range selected from any of these values. In some preferred embodiments, the isocyanate-containing emulsion may have a solids content of approximately 50%, 55%, 60%, 65%, or 70% by weight, with a suitable range selected from any of these values. In some embodiments, additional water may be used. For example, additional water may be added to dilute the emulsion immediately prior to board manufacturing. Viscosity can be controlled by adding water.

[0294] The binder mix comprises at least a thermoplastic dispersion and a crosslinker and can be used to produce plastic composites such as panels and boards. When the plastic composite is mixed with a lignocellulosic substrate / material, the board can be selected from fiberboard, oriented strand board, waferboard, particleboard, softboard, MDF, and / or hardboard.

[0295] In another example, the binder material is used in the manufacture of a composite material selected from the group consisting of fiber reinforced polymers (FRP), glass fiber reinforced polymers (GFRP or glass fiber), carbon fiber reinforced polymers (CFRP), aramid fiber reinforced polymers (AFRP, e.g., Kevlar), particle reinforced composites, polymer cements and concrete, metal matrix composites (MMC), laminated composites, plywood, laminated glass, adhesive-based composite joints or laminates. In another embodiment, the binder can be used as an adhesive, with or without a substrate.

[0296] The composite boards described address the industry's need to utilize recycled and waste plastic materials. Furthermore, these composite boards also offer greater durability and water resistance. In particular, the use of an isocyanate-based crosslinker incorporated into a thermoplastic polymer matrix results in a bond formed through an essentially irreversible reaction. This results in a more durable and moisture-resistant bond, which is particularly advantageous in applications where exposure to wet or humid conditions is anticipated. The isocyanate-thermoplastic binder improves water and moisture resistance, ensuring the longevity and integrity of the bond in harsh environments.

[0297] The crosslinking agent can be added in powder or other solid form. If added directly to the extruder / TSE, the crosslinking agent is typically added in a small amount of liquid form, i.e., dissolved in water. Additional water may be added to the extruder / TSE after the addition of the crosslinking agent.

[0298] If the crosslinking agent is a non-participating crosslinking agent, such as an organic peroxide, the emulsion may be dried to a moisture content of less than about 3% by weight.

[0299] When the crosslinker is a participatory crosslinker such as an isocyanate, drying is not believed to be necessary. That is, isocyanates have higher water resistance than organic peroxide-based crosslinkers. The presence of a high amount of water is believed to favor heat transfer during the board manufacturing process. The isocyanate-containing emulsion can have a solids content of about 30%, 40%, 50%, 60%, or 70% by weight, and a suitable range can be selected from any of these values. In some preferred embodiments, the isocyanate-containing emulsion can have a solids content of about 50%, 55%, 60%, 65%, or 70% by weight, and a suitable range can be selected from any of these values. In some embodiments, additional water can be used. For example, additional water can be added to dilute the emulsion immediately before board manufacturing. The addition of water can control viscosity.

[0300] Achieving a target moisture content in binders and composite boards produced according to the methods described herein is believed to be critical in determining bond and strength. Crosslinkers, such as isocyanates and organic peroxides, are highly reactive chemicals that can react with or be inhibited by hydroxyl groups present in lignocellulosic fibers. For example, isocyanate (-NCO) groups react with hydroxyl (-OH) groups to form urethane linkages (-NHCOO-). The moisture content in the wood fibers affects the availability of these OH groups. If the wood fibers are too dry, there will not be enough moisture to promote reaction with the isocyanates, resulting in poor adhesion and reduced board quality. Therefore, matching the moisture content of the board to the type of crosslinker used is particularly important.

[0301] The moisture content of the pre-press composite mixture containing the isocyanate may be greater than about 5%, which is useful to ensure that the isocyanate has sufficient bonding capacity.

[0302] Example 11 describes the preparation of composite mixtures with moisture contents of about 8% to 14%.

[0303] Furthermore, experimental testing has shown that boards containing composite mixtures produced in a press should have a total moisture content of less than approximately 15% before pressing. This minimizes the risk of problems such as excessive swelling and warping of the board during pressing and curing. Excessive steam generation within the board can cause bubbles to form, potentially leading to breakage. Therefore, the total moisture content of the composite mixture before pressing can be approximately 5% to approximately 15%.

[0304] A composite material mixture is described that includes an isocyanate-based crosslinker, a lignocellulosic substrate, and a thermoplastic dispersion as described herein, where the board has a moisture content of 5-15%.

[0305] Unconditioned lignocellulosic materials, such as wood chips, often have a moisture content of 8-12%, so binders containing a crosslinker and a thermoplastic dispersion preferably have a moisture content of less than 45%.

[0306] As shown in Examples 6 and 10, where organic peroxides were used, the inventors have found that high moisture content can compromise bonding. Thus, when the crosslinker includes an organic peroxide, the total moisture content of the board can be less than 10%. If a binder is used in 10% of the composite mix and an organic peroxide is used in 5% of the binder formulation, the moisture content of the thermoplastic dispersion is preferably reduced to less than 1% to obtain effective bonding.

[0307] The method for manufacturing a thermoplastic composite board generally involves placing a composite mixture into a press or mold containing a binder and fibrous or particulate lignocellulosic material. The composite mixture can contain about 4% to about 30% by weight of binder, with the remainder provided by the fibrous or particulate lignocellulosic material. Examples 6 and 11 provide several examples with different binder to composite mixture ratios.

[0308] It will be understood by those skilled in the art that a press or mold may include any device that applies heat and / or pressure to produce a flat or shaped solid product. Non-limiting examples of presses or molds may include 3D molds, injection molds, compression molds, transfer molds, or rotational molds that are capable of producing complex three-dimensional products.

[0309] In another example, the thermoplastic dispersions or binders described herein can be used as resins in other applications such as 3D printing.

[0310] The lignocellulosic material or fibrous or particulate substrate may include wood (e.g., sawdust, wood fibers, wood particles, wood chips, or wood sheets), coconut shells, rice straw or rice husks, barley straw, or bamboo. The choice of lignocellulosic material or fibrous or particulate substrate dictates the properties and applications of the composite product.

[0311] The examples provided herein describe several examples of composite board preparation using wood fibers, and Example 7 describes the preparation of composite boards using various other lignocellulosic materials.

[0312] In plywood and laminated wood type wood products, the wood may be in sheet form, which are glued together using a binder, and in this case the wood sheets may have a length of more than about 1 meter in at least one dimension.

[0313] In other products, such as oriented strand board, waferboard, particleboard, softboard, MDF, or hardboard, the lignocellulosic material / substrate may have a length of less than 500 mm in at least one dimension (e.g., a major dimension). For example, oriented strand board may include a lignocellulosic material / substrate having a major dimension of about 50 mm to about 500 mm. Waferboard may include a lignocellulosic material / substrate having a major dimension of about 10 mm to about 50 mm. Particleboard may include a lignocellulosic material / substrate having a major dimension of about 1 mm to about 15 mm. Softboard, MDF, and hardboard may include a lignocellulosic material / substrate having a major dimension ranging from about 1 mm to about 5 mm.

[0314] With respect to lignocellulosic materials / substrates, the substrate can be derived from various lignocellulosic material products. For example, fine-grade lignocellulosic materials / substrates can have an average particle size of about 0.5 mm, 1 mm, 1.5 mm, or 2 mm, and suitable ranges can be selected from any of these values ​​(e.g., about 0.5 mm to about 2 mm, about 0.5 mm to about 1.5 mm, about 0.5 mm to about 1 mm, about 1 mm to about 2 mm, about 1 mm to about 1.5 mm, or about 1.5 mm to about 2 mm). For example, fine-grade lignocellulosic materials / substrates can be derived from sawdust or wood flour. It will be understood that any raw material that yields a lignocellulosic material / substrate having the average particle size defined above is considered suitable for use. For example, comminution can be used, such as by using a hammer mill. The size of the particles produced in the mill system can be controlled by the use of a grinder screen, which is a screen with a mesh having a predetermined hole size.

[0315] The lignocellulosic material / substrate may be a coarser grade substrate having an average particle size of about 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, or 15 mm, and a suitable range may be selected between any of these values ​​(e.g., about 1 mm to about 15 mm, about 1 mm to about 13 mm, about 1 mm to about 10 mm, about 1 mm to about 8 mm, about 1 mm to about 5 mm, about 2 mm to about 15 mm, about 2 mm to about 14 mm, about 2 mm to about 10 mm). , about 2 mm to about 6 mm, about 3 mm to about 15 mm, about 3 mm to about 12 mm, about 3 mm to about 9 mm, about 4 mm to about 15 mm, about 4 mm to about 11 mm, about 4 mm to about 8 mm, about 5 mm to about 15 mm, about 5 mm to about 13 mm, about 5 mm to about 10 mm, about 6 mm to about 15 mm, about 6 mm to about 12 mm, about 6 mm to about 10 mm, about 6 mm to about 8 mm, about 7 mm to about 15 mm, about 7 mm to about 11 mm, about 8 mm to about 15 mm, about 8 mm to about 13 mm, about 9 mm to about 15 mm, about 9 mm to about 12 mm, or about 10 mm to about 15 mm). For example, coarser grade wood-based substrates can be made from wood chips and wood pellets.

[0316] When defining the size of lignocellulosic material particles as "average particle size," it will be understood that lignocellulosic material particles are not uniform in size. Recognizing that lignocellulosic material particles are often irregularly shaped, the average particle size represents the length of the longest axis.

[0317] The traditional method for obtaining particle size distribution is mechanical sieving. The American Society of Agricultural and Biological Engineers (ASABE Standard S424.1, 2007) developed mechanical sieving as the standard method for particle size analysis of biomass particles. Mechanical sieving determines the mass percentage of particles that remain on each sieve. However, since particles pass through the sieve based on their width, the sieving process does not take into account the length of the particle. Considering that particles are largely irregular and non-uniform in size and shape, two particles passing through the same sieve may have different shapes.

[0318] Rather than relying on traditional mechanical sieving methods, advanced technologies such as machine vision can be used to analyze particle size and shape using image analysis techniques. Image analysis is a practical method for determining the actual size and shape of a single particle. Image analysis is not subjective and can be performed repeatedly on the same image.

[0319] Another way to characterize the particle size of lignocellulosic materials is to examine the bulk density of the product. Smaller particles rearrange into more efficient packing, resulting in increased bulk density. For example, the bulk density of wood sawdust is approximately 370 kg / m 3 ~Approx. 415kg / m 3 is.

[0320] When a lignocellulosic-composite product is desired, the substrate can include both fine-grained and coarse-grained wood substrates, as described above. The board is formed by first preparing a fine-grained mixture and a coarse-grained mixture. The fine-grained mixture is prepared by mixing fine-grained wood fibers with a binder comprising a functionalized thermoplastic and a crosslinking agent. The coarse-grained mixture is prepared by mixing coarse-grained lignocellulosic fibers with a binder comprising a functionalized thermoplastic and a crosslinking agent.

[0321] To form a board, a layer of the fine-grained composite mixture may be first laid on the bottom of a mold, followed by a layer of the coarse-grained composite mixture, and then a layer of the fine-grained composite mixture on top of the coarse-grained composite mixture. The resulting composite is then pressed under pressure and heat. In some embodiments, the ratio of the fine-grained composite mixture to the coarse-grained composite mixture is about 20:80 to 80:20. It will be appreciated that the fine-grained composite mixture may be split into layers for use as the top and bottom layers when prepared. The split ratio is typically 40:60:60:40, with a ratio of about 50:50 being preferred.

[0322] The ratio of the coarse composite mixture to the fine composite can be 20:80 to 80:20 as previously mentioned, with ratios of 40:60 to 60:40 also being contemplated.

[0323] In one preferred embodiment, the board is formed from 20% by weight fine composite mixture, followed by 60% by weight coarse composite mixture, followed by 20% by weight fine composite mixture.

[0324] For plywood-type composite products, the binder is placed between the sheets, for example, by spraying or painting the binder.

[0325] The composite is formed into a mat in a press. The mat may be pre-compressed in a continuous press to make the mat more compact before being placed in the hot press, or it may go through another step in a discontinuous press. The thickness of the composite is reduced by pressing, so that the final cured product can be about 10%, 15%, 20%, 25%, 30%, or 35% of the thickness of the original composite mixture before pressing and heating.

[0326] The pressure applied to the composite material mixture may be about 3 MPa, 4 MPa, 5 MPa, 6 MPa, 7 MPa, 8 MPa, 9 MPa, or 10 MPa, and a suitable range can be selected from between any of these values ​​(e.g., about 3 MPa to about 10 MPa, about 3 MPa to about 9 MPa, about 3 MPa to about 7 MPa, about 3 MPa to about 6 MPa, about 3 MPa to about 5 MPa, about 4 MPa to about 10 MPa, about 4 MPa to about 8 MPa, about 4 MPa to about 6 MPa, about 5 MPa to about 10 MPa, about 5 MPa to about 8 MPa, about 5 MPa to about 7 MPa, about 6 MPa to about 10 MPa, about 6 MPa to about 9 MPa, or about 7 MPa to about 10 MPa).

[0327] The temperature of the press or mold is such that the composite material is heated to about 100 to about 220°C. This is a temperature sufficient to melt the binder and allow it to coat and bond the substrate to form the product. In some embodiments, some of the thermoplastic in the binder may not melt, which is believed to be the case when the binder contains contaminant thermoplastic. That is, while the thermoplastic in the binder melts sufficiently to form a continuous phase that coats the substrate, some of the thermoplastic in the binder may not melt and remain as particulates in the composite material.

[0328] Several factors can affect the hot pressing process, including press temperature, mat moisture content (MC), press closure speed, resin properties, and wood chip particle type. The rate at which the press temperature is increased particularly affects the adhesive cure rate. This not only affects the total press time, but also plays an important role in creating vertical density gradients within the material. Among these factors, the mat moisture content has a significant impact on heat transfer within the mat. The rate at which heat penetrates the mat determines the required press time. The higher the MC of the mat, the more energy is required for water evaporation.

[0329] It will be appreciated that the upper and lower fine particle mixture layers may be exposed to greater heat than the inner coarse particle mixture layers. With this in mind, the functionalized thermoplastic used in the binder for the fine particle mixture may be comprised of a functionalized thermoplastic having a higher melting point than the plastic used in the binder for the coarse particle mixture (used in the middle layer of the board).

[0330] Each fine grain layer may comprise 5%, 10%, or 15% of the total thickness of the mat, and a suitable range may be selected between any of these values.

[0331] The functionalized thermoplastic may be a blend of low-density or high-density PE and PP. The functionalized thermoplastic may contain a small amount of mixed thermoplastic. The composite mixture is subjected to sufficient pressure to reduce the thickness of the composite mixture, after which the composite mixture is heated to approximately 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, 180°C, 190°C, 200°C, 210°C, or 220°C to form a wood composite panel, with a suitable range being selected between any of these values.

[0332] A release agent may be applied to the press surfaces to prevent the composite from sticking to the press platens. In some embodiments, the outer layer of the composite, such as the UF granule composite mixture layer described above, may contain urea formaldehyde to prevent the composite from sticking to the press.

[0333] The particle size of the functionalized thermoplastic may be smaller for fine fibers compared to coarse fibers, i.e., to effectively coat the fine fibers, it is believed that it is best to utilize thermoplastic particles with a smaller average particle size to ensure good coating of the fine lignocellulosic fibers.

[0334] The cross-linking agents used in the fine and coarse mixtures may be different, for example, the cross-linking agent used in the fine mixture may be selected based on its performance at high temperatures, while the cross-linking agent used in the coarse layer may be selected based on its performance at low temperatures.

[0335] The fine layer may have a higher moisture content than the coarse layer.

[0336] The composite mixture may also include additives, which may be present in the binder. a) accelerators, b) modifiers; c) an activator, and / or d) Catalyst You can choose from one or more of the following:

[0337] Regarding the accelerator, the accelerator may be an amine-based accelerator. More specifically, the accelerator may be a toluidine-based accelerator. Specifically, the accelerator may be selected from N-(2-hydroxyethyl)-N-methyl-para-toluidine, ethoxylated para-toluidine, N,N-dimethyl-para-toluidine, N,N-dihydroxyethyl-para-toluidine, diisopropoxy-para-toluidine, or a combination thereof.

[0338] The binder may include 0.5%, 1.0%, 1.5%, 2.0%, 2.5%, or 3.0% by weight of the binder of the accelerator, and a suitable range may be selected between any of these values.

[0339] Without wishing to be bound by theory, the accelerator increases the amount of free radicals produced by the crosslinker, increasing the rate of polymerization of the functionalized thermoplastic material to a thermoset material.

[0340] The resulting boards can have a modulus of elasticity (MoE) of approximately 1000 MPa, 1500 MPa, 2000 MPa, 2500 MPa, 3000 MPa, 3500 MPa, or 4000 MPa, with an appropriate range selected between any of these values. Static bending tests are often used for mechanical stress rating (MSR) of wood-based products. MSR is currently the most common dynamic mechanical loading procedure. The board is passed lengthwise in a flat state through a machine and bent into two sections, one above the other, by rollers. The distance between the rollers is typically approximately 1.2 m. Depending on the design, the machine either bends the board to a fixed deflection and measures the force required, or it bends the board at a fixed force and measures the deflection. Using the load-deflection relationship, the local MOE can be directly determined at all points on the board except for the first and last approximately 500 mm, using equations derived from the fundamental mechanics of materials. This test method allows the stiffness profile of the board to be determined.

[0341] The resulting composite board has a modulus of rupture (MOR) of approximately 5, 10, 15, 20, or 25 MPa, with suitable ranges selected between any of these values. MOR (sometimes called flexural strength) is a measure of the strength of a test specimen before fracture. It differs from modulus of elasticity, which measures wood deflection and can be used to determine the overall strength of wood-based products, but not their ultimate strength. MOR "sigma" can be calculated using the formula σr = 3Fx / yz2, where F is the load and the material's three dimensions (x, y, and z). In this case, the load is the external force acting on the material. The load force is applied to the center of the composite product, with the material elevated slightly above ground level.

[0342] In some embodiments, the surface screw retention force of the composite product is about 200 N, 250 N, 300 N, 350 N, 400 N, 450 N, or 500 N, and a suitable range can be selected between any of these values ​​(e.g., about 200 N to about 500 N, about 200 N to about 400 N, about 200 N to about 300 N, about 250 N to about 500 N, about 250 N to about 450 N, about 250 N to about 350 N, about 300 N to about 500 N, about 300 N to about 450 N, about 350 N to about 500 N, about 350 N to about 450 N).

[0343] The density of the composite board can be controlled by the amount of compression applied in the press or mold. For example, about 550 kgm 3 , 560kgm 3 , 570kgm 3 , 580kgm 3 , 590kgm 3 , 600kgm 3 , 610kgm 3 , 620kgm 3 , 630kgm 3 , 640kgm 3 , or 650 kgm 3 Lower pressures can be used to obtain low density composite boards having densities of 0.1 to 0.5 mm, and a suitable range can be selected between any of these values.

[0344] Approximately 650 kgm 3 , 700kgm 3 , 750kgm 3 , or 800 kgm 3 Higher pressures can be used to obtain medium density composite boards having densities of 0.1 to 0.5, and a suitable range can be selected between any of these values.

[0345] Approximately 800 kgm 3 , 850kgm 3 , 900kgm 3 , 950kgm 3 , 1000kgm 3 , 1050kgm 3 , or 1100 kgm 3 Higher pressures can be used to obtain high density composite boards having densities of 0.1 to 0.5, and a suitable range can be selected between any of these values. [Example]

[0346] standard method Unless otherwise indicated, the following test methods and board properties were used in the examples presented below:

[0347] [Table 2]

[0348] Example 1 - Characterization of Thermoplastic Polymers the purpose Analyses were conducted to characterize the composition and properties of various plastics, which is an important first step when using unknown waste / recycled plastics, especially when downstream processes (e.g., functionalization and emulsification) are sensitive to the properties and composition of the feedstock.

[0349] method FTIR analysis LDPE (Astron) recycled from industrial waste was analyzed to assess the amount of LDPE and other polymers. Four different blends were prepared from recycled PP pellets and recycled LDPE pellets from industrial waste as calibration standards. The pellets were homogeneously mixed and fed into a twin-screw extruder using a gravimetric feeder. After the extrudate output stabilized, it was pelletized and recovered. The pellets were dried overnight in an oven at 40°C to remove any moisture present. Measurements were performed using a PerkinElmer Spectrum Two FT-IR equipped with a diamond ATR accessory according to the manufacturer's instructions. The wavelengths were measured over a range of 400-4000 wavenumbers (cm). -1 ) averaged over four scans, with a resolution of 4 cm -1 For each blend, six pellets were randomly selected and measured. Data were processed using PerkinElmer Spectrum IR software and analyzed at 1377 cm -1 and 1462 cm -1 The peak areas of the PP and PE were analyzed. The quantification method uses the ratio between the CH umbrella in-phase bending mode (mainly PP) and the CH and CH bending modes present in both PE and PP.

[0350] Differential scanning calorimetry Differential scanning calorimetry (DSC) was performed according to the manufacturer's instructions.

[0351] Analyzed samples The following samples were analyzed:

[0352] [Table 3]

[0353] result The results and conclusions for each plastic are given below:

[0354] 1a - Results - Industrial waste LDPE FIG. 8A shows the DSC analysis results for Sample 1a (industrial waste pelletized LDPE).

[0355] [Table 4]

[0356] 1a-Conclusion The first melting peak at 106°C in the DSC curve is indicative of LDPE. This peak is broad, indicating heterogeneity of chain lengths. The second melting peak at 125°C is sharp, indicating medium density PE with uniform chain lengths. No HDPE or PP contamination is observed.

[0357] 1b-Results-Analysis of agricultural waste film

[0358] [Table 5]

[0359] [Table 6]

[0360] Figure 8b shows the melt flow index at different temperatures. Figure 8c shows the DSC analysis of Sample 1b, showing distinct peaks corresponding to different compounds.

[0361] 1b-Conclusion The first melting peak in the DSC curve is at 111°C and is broad in nature. This peak is indicative of LDPE with heterogeneous chain lengths. The second melting peak at 123°C is sharp and indicative of medium-density PE with homogeneous chain lengths. No HDPE or PP contamination is observed.

[0362] 1c - Results - Analysis of industrial waste film

[0363] [Table 7]

[0364] Figure 8d shows the DSC analysis results for sample 1c.

[0365] 1c-Conclusion The broad, single melting peak at 111.23°C in the DSC curve indicates LDPE with heterogeneous chain lengths. No MDPE, HDPE, or PP contamination is observed.

[0366] 1d - Results - Analysis of virgin LDPE A

[0367] [Table 8]

[0368] Figure 8e shows the DSC analysis of sample 1d, showing a clear peak corresponding to LDPE.

[0369] 1d-Conclusion The DSC curve of sample 1d shows a sharp single peak at 113.14°C, suggesting that it is a high-quality LDPE.

[0370] 1e - Results - Analysis of virgin LDPE B

[0371] [Table 9]

[0372] 1e-Conclusion Analysis shows a relatively high melt flow index.

[0373] Example 2 - Preparation of the binder This example demonstrates the production of wood fiber boards from thermoplastic dispersions using a variety of LDPE feedstocks and processing conditions.

[0374] method

[0375] [Table 10]

[0376] The three LDPE samples were processed through a twin screw extruder at the temperature settings indicated above.

[0377] The polymer samples were premixed with polyvinyl alcohol pellets (5% w / w and 10% w / w) and fed to the extruder feed to increase processing efficiency. The PVOH increased the flow of the sample through the twin-screw extruder. No breakage due to high pressure / torque was observed. Water was added to achieve a final water content of 50-70% in the thermoplastic dispersion.

[0378] The thermoplastic dispersion was collected from the twin-screw extruder and mixed with eMDI and wood fiber using a paddle mixer. Composite mixtures and boards were prepared according to the protocol described in Example 3.

[0379] result

[0380] [Table 11]

[0381] Physical test results of different binder materials for wood fiberboards

[0382] [Table 12]

[0383] [Table 13]

[0384] [Table 14]

[0385] conclusion Virgin LDPE B has an MFI of 21.4, while virgin LDPE A has an MFI of 2g / 10min.

[0386] Both LDPE A and LDPE B provided thermoplastic dispersions that were used to make wood fiber boards with excellent board properties.

[0387] The level of PVOH in the binder affected the mechanical strength of the boards produced with that binder. In particular, 5% PVOH resulted in stronger boards compared to 10% PVOH. Furthermore, the addition of 5% PVOH improved the melt flow of the thermoplastic through the extruder. The addition of PVOH is believed to provide additional hydroxyl groups to bond with the isocyanate functional groups. Supersaturation with 10% PVOH adversely affected the strength of the wood fiber board.

[0388] Example 3 - Preparation of Mixed Waste Polymer Binder This example demonstrates the production of binders made from recycled polypropylene and recycled polyethylene, which represent a high melting point thermoplastic (PP has a melting point of approximately 171°C) and a low melting point thermoplastic (LDPE has a melting point of approximately 106°C). Three thermoplastic processes were tested: a. Recycled PP (Yuplene): Recycled industrial waste LDPE (Astron) 1:1 b. Recycled PP (Yuplene): Recycled industrial waste LDPE (Astron) 1:4 c. 100% recycled industrial waste LDPE (Astron)

[0389] The three raw materials were processed using a twin-screw extruder to prepare a thermoplastic dispersion, which was then used to manufacture wood fiberboards and tested for strength properties.

[0390] Three mechanical tests were performed to determine the effect of varying the thermoplastic ratio on the modulus of elasticity (MOE), modulus of rupture (MOR), and internal bond strength (IB). This example provides insight into the potential use of high-melting recycled thermoplastics, such as PP, and low-melting recycled thermoplastics, such as LDPE, as sustainable alternatives to improve the processability and / or tailor the mechanical performance of wood fiber composite boards.

[0391] method Preparation of binder The raw materials were homogenized through a twin-screw extruder to mix the different plastic sources and produce thermoplastic pellets. The thermoplastic pellets were passed through the twin-screw extruder while adding water to promote emulsification and particle size reduction to produce a thermoplastic dispersion.

[0392] Three identical boards were produced using binders prepared from the three thermoplastic dispersions, using identical twin-screw extruder emulsification conditions.

[0393] [Table 15]

[0394] The twin screw extruder temperature profile shown in the table above incorporates a higher initial temperature to melt the thermoplastics prior to mixing.

[0395] The extruder contained two water injection stations. Two surfactants were used, Dowfax 2A-1, an anionic surfactant, and Teric 463, a nonionic surfactant, at the first and second injection stations, respectively. The surfactant loading was adjusted to a 4% w / w surfactant to resin ratio. Water was injected at injection station 1 (post-melt zone) and injection station 2 (dilution zone). The water flow was adjusted to achieve a resin:water ratio of 3.5 after injection station 1 and a resin:water ratio of 1.3 after injection station 2.

[0396] During processing, the torque (current in amps) measurements of the twin-screw extruder were evaluated and rated on a scale ranging from 1 (lowest processability / highest current) to 5 (highest processability / lowest current), which indicates the processability of the recycled material and correlates with energy consumption. Initial tests using recycled industrial waste LDPE failed due to high torque / current values ​​that caused the extruder to stall.

[0397] After processing in the extruder, the moisture content of the dispersion was adjusted by drying for 24 hours so that the moisture content of the composite mixture was 8-12%. The thermoplastic dispersion was mixed with emulsified methylene diphenyl diisocyanate (eMDI) for 10 minutes. 1% by weight of the composite mixture was eMDI. 500 g of coarse wood chips were added in two portions and mixed for 10 minutes each to prepare the composite mixture.

[0398] Making the board The mixed formulation was dispensed into a mold on a platen and flattened to create a mat with consistent height and uniform material distribution. The mat was pre-compressed with a force of 5 tons and then hot pressed with a press factor of 12 and a target density of 620 to produce a compressed wood fiber board.

[0399] Board Exam To investigate the differences in the effects of different combinations of recycled PP and PE on mechanical strength, MOE, MOR, and IB tests were carried out on four strips from three replicate boards per treatment.

[0400] During processing, torque measurements were evaluated for each sample to provide an indication of processability.

[0401] result

[0402] [Table 16]

[0403] MOE - The table above shows the average modulus of elasticity for the three treatment groups. 50% recycled PP had the lowest average MOE at 1774 MPa, while LDPE alone had an MOE of 1811 MPa. The MOE did not trend significantly (P>0.1), indicating that the more LDPE, the higher the MOE.

[0404] MOR - The table above shows the average MOR for the three treatment groups. The average modulus of rupture for the three treatment groups was 11.817 MPa (50 / 50 = recycled PP / recycled LDPE), 12.82 MPa (20 / 80 = recycled PP / recycled LDPE), and 13.140 MPa (100% recycled LDPE). There was no significant trend (P > 0.05) for a higher MOR with higher LDPE content.

[0405] IB - The table above shows the average IB for the three treatment groups. The average internal bond strength for the three different board compositions was negatively correlated with the percentage of recycled LDPE. However, there were no significant differences in the average values ​​between treatment groups (p>0.05).

[0406] Processability - With increasing PP content, the processability of the samples improved, i.e., the energy consumption required for processing decreased and the likelihood of clogging decreased.

[0407] Melt Flow Index - The table below shows that as the percentage of LDPE in the blend increases, the melt flow index (measured at 190°C) clearly increases.

[0408] [Table 17]

[0409] conclusion The results show that recycled high melting point thermoplastics and recycled low melting point thermoplastics, including blends of PP and LDPE, can be used to produce wood fiber boards without adversely affecting MOE or MOR. With increasing PP content, the processability of the blends improved. This testing demonstrates that the described method allows for the processing of high melting point materials to produce binder and wood fiber boards with improved processability, reduced energy consumption, and consistently high strength.

[0410] Recycled PP has a high melting point of about 171°C. Recycled LDPE has a low melting point of about 106°C. Increasing the PP content in the blend increased the melt flow index, which resulted in advantageous torque reduction and improved processability in a twin-screw extruder. This example demonstrates that blends of recycled PP and LDPE can provide usable wood fiber boards after processing in an extruder. It also demonstrates that adding recycled PP to the blend can improve the melt flow index; for example, adding at least 50% recycled PP to a blend of LDPE and PP improves processability and mixability.

[0411] Example 4 - Characterization of recycled thermoplastic materials for improved processability This example demonstrates a preprocessing characterization step used in some embodiments to customize extrusion parameters in the methods and apparatus described herein. Specifically, this example provides a numerical model for characterizing waste thermoplastic polymers to determine the PP:LDPE ratio and adjust processing parameters. This allows for the determination of unknown thermoplastic properties, followed by adjustment of extrusion parameters, and optionally process functionalization parameters, to prepare reinforced thermoplastic dispersions for board manufacturing, thereby improving the processing and energy efficiency of the extrusion process. Waste polypropylene (PP) was blended with waste low-density polyethylene (LDPE), and the melt flow index was measured at temperatures between 190°C and 230°C according to ASTM D1238.

[0412] result

[0413] [Table 18]

[0414] Figures 9a-9e are calibration curves showing experimental results of varying the recycled PP:LDPE composition as a function of the natural logarithm of the average MFI at different set temperatures from 190°C to 230°C.

[0415] [Table 19]

[0416] Consideration A linear regression was obtained between the percentage of polypropylene (PP) and the melt flow index at various temperatures (190°C, 200°C, 210°C, 220°C, and 230°C) during the melt flow index test. This linear relationship provides a method for determining the PP level in waste thermoplastic polymer blends. Determining the PP and LDPE composition allows for the preparation of thermoplastic dispersions and modification of extrusion emulsions to enhance the mechanical properties of wood fiberboards.

[0417] Example 5 - Preparation of Composite Boards Using Isocyanates This experiment describes the production of wood fiber composite boards made using thermoplastic dispersions and the isocyanate variant polymeric methylene diphenyl diisocyanate (PMDI) and an aqueous emulsion of PMDI (EMDI).

[0418] method A thermoplastic dispersion was prepared by twin-screw extrusion processing from virgin LDPE A blended with 5% PVOH according to the method and twin-screw configuration outlined in Example 3. Wood fiber boards were made according to the mixing and board pressing procedures outlined in Example 3. Duplicate runs were made.

[0419] result

[0420] [Table 20]

[0421] [Table 21]

[0422] Figures 10a-10c show the average MOE, MOR, and IB of boards manufactured using eMDI and pMDI. eMDI exhibited higher average MOE (2247.07 MPa), MOR (14.23 MPa), and IB (0.825 MPa) compared to the MOE (2077.5 MPa), MOR (13.63 MPa), and IB (0.7 MPa) of pMDI.

[0423] conclusion High-quality wood fiber boards were produced using eMDI and pMDI using LDPE thermoplastic dispersions. eMDI provided boards with higher strength compared to pMDI.

[0424] Example 6 - Use of maleic anhydride functionalized PE to make wood fiber composite boards Composite boards containing wood fibers and maleic anhydride-functionalized PE were formed using Luperox 231 (1,1-di-(tert-butylperoxy)-3,3,5-trimethylcyclohexane), an organic peroxide-based crosslinker.

[0425] method The binder was prepared by blending virgin LDPE A (Exxon) and polyvinyl alcohol in a twin-screw extruder and then emulsifying to form a thermoplastic dispersion. Dispersion preparation and board testing were as described above in Example 3. The thermoplastic dispersion was dried overnight in an oven to achieve a moisture content of approximately 50%.

[0426] The composite mixture contained: Coarse wood chips 90% (moisture content 8-12% by weight) Binder 10%

[0427] Two replicates of each binder composition were made according to the following binder compositions: Samples 1a and 1b: Thermoplastic dispersion prepared using LDPE 87% PMDI 10% ·Organic peroxide crosslinker (Luperox231) 3% w / w. Samples 2a and 2b: Thermoplastic dispersion prepared using LDPE 62% PMDI 10% Organic peroxide crosslinker (Luperox231) 3% w / w Maleic anhydride grafted PE 25% (grafted with 1% MA).

[0428] The binder was mixed in, then wood chips were added and further mixed. The material was transferred to a mold and flattened. After pre-compression, the boards were hot pressed at 200°C with a press modulus of 12 seconds / mm.

[0429] result

[0430] [Table 22]

[0431] FIG. 11 shows that when functionalized PE is used as a component in wood fiber boards, the average board strength, as measured by MOE, is significantly higher.

[0432] conclusion MAPE is thought to promote bonding between LDPE and wood particles. Functionalization of PE with MA strengthens the adhesion of LDPE to wood fibers within particleboard. The results indicate that polyethylene functionalized with maleic anhydride provides composite boards with higher strength than those without MAPE.

[0433] Example 7 - Alternative lignocellulosic materials the purpose This example explores several lignocellulosic substrates that can be included in composite boards containing the thermoplastic dispersions described herein.

[0434] method For comparison with pine wood chips, two other lignocellulosic substrates were tested: bean straw and barley straw, which have a coarse, fibrous texture and are often used for water retention in horticultural and agricultural applications.

[0435] The mechanical strength was tested according to standard methods.

[0436] pMDI was used as the crosslinker at 10 wt% of the binder. A thermoplastic dispersion containing LDPE (Exxon) was used. The biaxial setup for dispersion preparation was as described in Example 3. The polymer melt flow index was 2 g / 10 min at 190 °C. The moisture content of the lignocellulosic substrate was normalized to 10 wt%. 10 wt% of the board composition was accounted for by the binder. For testing, 10 mm thick 620 kg / m 3 A board was created.

[0437] result Table 17 below shows the results of the mechanical strength tests for each board:

[0438] [Table 23]

[0439] Consideration The mechanical strength of boards made with barley straw was highest as measured by MOR and MOE. Barley straw typically has a high lignin content compared to other crop residues. The lignin content of barley straw is estimated to be in the range of 15%-20%, while that of legume straw is in the range of 5-15%.

[0440] This experiment demonstrates that a variety of lignocellulosic substrates can be used to manufacture composite boards.

[0441] Example 8 - Effect of GMA Grafted PP on Processing and Board Performance GMA was grafted onto recycled polypropylene thermoplastics, and the processability during the extrusion process and the mechanical strength of the resulting boards were evaluated.

[0442] method Recycled PP (rPP) was gravimetrically fed at 2 kg / h before the melt zone. Glycidyl methacrylate, styrene monomer, and dicumyl peroxide solution (1:1:0.1) were premixed and then injected into the twin-screw extruder at 6.5 ml / min. The barrel temperature was maintained above 180°C, and the screw speed was maintained at 200 rpm. After exiting the die, the extrudate was immediately cooled and pelletized.

[0443] For characterization, 1 g of the product was dissolved in xylene, precipitated in acetone, and then dried for 24 hours at 60° C. Grafting was confirmed by FTIR.

[0444] These pellets of rPP-g-St-GMA were fed into another extruder at 1.5 kg / hr. The extruder configuration was identical to that of Example 3, except that the melt zone was hotter (>160°C) to ensure complete melting of the polypropylene. The resin / water ratio after injection 1 was 1.2 and after injection 2 was 0.5. Unfunctionalized recycled polypropylene was used as a control and sized in the same manner.

[0445] result Figure 12a shows a typical FTIR spectrum of polypropylene, with no apparent carbonyl or epoxide peaks. Figure 12b shows the peak at approximately 1730 cm -1 Strong absorption of the C=O carbonyl stretching and approximately 900 cm -1 The much smaller COC epoxide peak located at 1000 nm indicates successful grafting of glycidyl methacrylate.

[0446] The emulsified pellets were dried and analyzed under a 1.0 mm optical microscope. Figures 12c and 12d show microscopic images of rPP and rPP-St-GMA, respectively. These results indicate that the average particle size is reduced when rPP-St-GMA is used as the feed for the SFEE process instead of rPP. The inclusion of GMA significantly reduces the large agglomerates that make up the entire thermoplastic dispersion.

[0447] conclusion We successfully functionalized recycled PP with GMA using a solvent-free melt grafting method in a co-rotating twin-screw extruder. The presence of peaks typical of carbonyl compounds is evidence of successful GMA grafting. The introduction of hydrophilic monomers into the hydrophobic polymer backbone reduced the surface tension at the resin-water interface, decreasing the frequency of particle aggregation and the average particle size of the dispersion.

[0448] PP is a hydrophobic polymer and is insoluble in water. This prevents the homogeneous mixing of the two phases during emulsification. Improved dispersibility and stability can be achieved by incorporating hydrophilic moieties (e.g., GMA) into the backbone. A more hydrophilic thermosetting plastic reduces the contact angle between the hydrophilic lignocellulosic material and water in the composite board, thereby enhancing mechanical anchoring and resulting in improved MOE and MOR. The reactive epoxide in GMA provides reactive functionalization of the thermoplastic material to form an effective binder.

[0449] Example 9 - Use of Carboxylic Acids to Functionalize Recycled PE This example demonstrates how grafting functional groups onto the rLDPE backbone prior to the SFEE process can improve the emulsion stability of recycled LDPE (rLDPE) and enhance the bond strength of thermoplastic dispersions produced by SFEE technology. Performance evaluation of methacrylic acid-grafted rLDPE particleboard is performed.

[0450] method synthesis Recycled LDPE, water, methacrylic acid, and styrene are placed in a round-bottom flask in a ratio of 3.3:2.3:1:0.1. The mixture is gently stirred and heated to 93°C. After reaching the reaction temperature, the initiator dicumyl peroxide is added at 1.5% relative to the LDPE, and the system is continuously stirred for three hours. The grafted LDPE is washed three times: first with 0.1M caustic solution, then with 0.1M hydrochloric acid, and finally with deionized water.

[0451] A dispersion is then prepared from the resulting functionalized polymer, for example, as described in Example 3 above.

[0452] Oven Stability The viscosity of the polymer is measured 72 hours after preparation using a Brookfield RVT viscometer. It is then placed in a 200 mL screw-cap glass bottle and artificially aged in a 60°C oven for two weeks. After the accelerated aging is complete, the sample is evaluated for roughness and viscosity.

[0453] Particleboard adhesive performance A series of boards are manufactured and tested to the EN312 standard for P3 particleboard, with half of the boards using a grafted rLDPE adhesive and the other half using a similar adhesive that is not grafted.

[0454] result Oven Stability Grafting reduces particle concentration and also reduces viscosity drift that occurs during accelerated aging.

[0455] Crosslink density and performance evaluation An improvement in modulus is expected to be observed, suggesting improved compatibility of the components within the recycled LDPE and / or improved adhesion between the wood fiber particles and the polymer. While the acid functionality provides sites for isocyanate to react with the polymer, the pMDI is expected to react more with water in the system than the acid groups along the polyolefin backbone.

[0456] conclusion This experiment demonstrates that acid-grafted rLDPE dispersions have excellent storage stability and provide improved adhesion properties in particleboard applications, allowing composite boards with lower pMDI:rLDPE ratios to be produced that meet the P3 particleboard specification as outlined in EN312.

[0457] Example 10 - Preparation of functionalized PE for wood fiber board production using peroxide crosslinker This example illustrates the use of a maleic anhydride compatibilizer to increase crosslinking in making wood fiber boards from thermoplastics.

[0458] method Two different waste LDPE raw materials (AXM1 and V plas) were used. AXM1 and V plas were produced by different mechanical processes. Isopropyl alcohol was used as a tackifier in the binder preparation.

[0459] Wood fiber boards were prepared and hot pressed at a press modulus of 22 seconds / mm, and the mechanical properties of the boards of each formulation were analyzed.

[0460] Wood fiber board manufacturing Crosslinking agent (Luperox231) Maleic anhydride grafted PE (grafted with 1% MA) Isopropyl alcohol (IPA) Wood chips: coarse and fine wood chips Pressing rate: 22 sec / mm

[0461] Binder, crosslinker (Luperox 231), MAPE, and IPA were mixed. 20% of the total board volume was fine wood chips, and 80% of the total volume was coarse chips. A three-layer wood fiber board mattress composition was formed containing 10% by volume of fine chips, 80% by volume of coarse chips, and the remaining 10% by volume of fine chips. The material was pre-compressed in a mini-press to form a mattress, which was then pressed in a hot press at a press modulus of 22 mm / sec to produce a 15 mm board. The board was cooled and tested.

[0462] result

[0463] [Table 24]

[0464] Figure 13a shows the results for 20% AXM1, 5% P231, IPA, 10:80:10, F / C / F, press time 4.5+1 min 680 kg / m3, SP temperature 190 °C.

[0465] [Table 25]

[0466] Figure 13b shows the results for 20% AXM1, 25% MAPE, IPA, 10:80:10, F / C / F, press time 4.5+1 min 680 kg / m3, SP temperature 190 °C.

[0467] [Table 26]

[0468] Figure 13c shows the results for 20% V Plas, 25% MAPE, IPA, 10:80:10, F / C / F, press time 4.5+1 min 660 kg / m3, SP temperature 190 °C.

[0469] Consideration High strength wood fiber boards were obtained with various concentrations of peroxide crosslinker. Waste LDPE binder treated with both Vplas and AXM1 showed similar mechanical strength at all peroxide crosslinker concentrations.

[0470] Effect of MAPE Compatibilizer on Wood Fiber Boards - As shown in Figure 13a, adding functionalized PE at concentrations greater than 0% improved the strength of the board. The addition of MAPE increased the MoE strength by 700-1000 MPa and the MoR strength by 3-6 MPa. MAPE acts as a bridge between the hydrophobic LDPE matrix and the hydrophilic wood fibers. It has both polar and non-polar components in its molecular structure. This dual nature allows MAPE to improve the adhesion and bonding between LDPE and wood fibers, making the interface more compatible.

[0471] It was observed that MAPE has a shorter half-life when in contact with water, so optimal results were obtained by using dry lignocellulosic fibers with a moisture content of less than 5 wt% in the composite mixture.

[0472] Example 11 - Recycled Thermoplastic Dispersion Used in the Production of Wood Fiber Boards This example describes the preparation of thermoplastic dispersions from four different waste thermoplastics (low-density polyethylene and polypropylene) and one virgin LDPE. The fabrication of composite boards containing wood fibers is described.

[0473] method Thermoplastic samples were prepared as pellets and fed into a twin-screw extruder of the configuration outlined below. The water flow rate was adjusted to achieve a water content of 45% to 55% in the thermoplastic dispersion.

[0474] To improve the processability of the extruded thermoplastic dispersion and reduce particle size, two samples were prepared using a 1:1 PE / PP blend. The first sample contained a 1:1 mixture of industrial waste LDPE (Astron) and recycled PP. The second sample contained a 1:1 mixture of agricultural waste LDPE film and recycled polypropylene. Each blend was passed through a twin-screw extruder for mixing and then through a second twin-screw extruder to prepare the thermoplastic dispersion.

[0475] [Table 27]

[0476] The TSE temperature profile was kept constant for all samples.

[0477] [Table 28]

[0478] Two identical boards were prepared for each treatment, and the moisture content of the resulting binders was evaluated.

[0479] result

[0480] [Table 29]

[0481] [Table 30]

[0482] 14a-14d show the results of the MoE, MoR, IB, and 24-hour swelling tests.

[0483] conclusion The torque and current data for the twin-screw extruder indicate the processability of the binder for each process. The torque measured in the twin-screw extruder reflects the shear forces that can induce mixing within the TSE. Polymers with high melt flow index (MFI), such as virgin LDPE A and recycled PP, exhibit lower torque. Polymer blends, especially Astron / rePP and Bale Wrap / rePP, reduce torque when combined with the high MFI of recycled PP.

[0484] The MoE and MoR showed that all processed thermoplastic dispersions provided binder compositions with acceptable board properties. Post-industrial LDPE (Astron) showed superior performance compared to dispersions of other types of post-industrial thermoplastics.

[0485] Virgin LDPE produced stronger composite boards, likely due to additives or contaminants in the waste thermoplastic interfering with the bonding properties of the crosslinker.

[0486] The internal bond strength determines the bond between the wood fibers and the polymer binder. The four different waste polymer binders showed similar internal bond strengths of approximately 0.2–0.3 MPa.

[0487] The internal bond strength of virgin LDPE A binder was 0.5 MPa, which is two times greater than that of binder boards based on waste thermoplastic polymers, suggesting that waste thermoplastics may lose bond strength due to additives or contaminants.

[0488] The swelling rates observed over 24 hours in water suggest that recycled polypropylene boards have a significant tendency to absorb water. This swelling rate appears to depend on the moisture content of the board both before and during the manufacturing process. Interestingly, and contrary to expectations, boards with lower initial moisture contents exhibited higher water absorption rates and were more prone to swelling. Experimental results show that recycled polypropylene boards with a moisture content of 9.14% exhibited swelling rates of over 60% within 24 hours. Furthermore, Astron with a moisture content of 8% and Astron / PP with a moisture content of 9.53%, both of which are considered to have low moisture contents, exhibited elevated swelling rates within 24 hours.

[0489] Example 12 - Optimization of binder content in wood fiber boards using recycled thermoplastic dispersions This example explores various ratios of binder and crosslinker to produce composite boards containing wood fibers.

[0490] method Thermoplastic dispersions were prepared in a twin-screw extruder. The thermoplastics included virgin LDPE B (MFI: 20 g / 10 min, 190 °C) blended with 5% (wt%) PVOH in the twin-screw feed before emulsification to improve processability. Wood fiber boards had a density of 620 kg / m 3 It was compounded with.

[0491] [Table 31]

[0492] [Table 32]

[0493] The binder ratio and isocyanate (eMDI) content were varied to determine the optimum ratio.

[0494] result

[0495] [Table 33]

[0496] Figure 15A shows the change in modulus of elasticity (MoE) for different board treatments.

[0497] Figure 15b shows the variation of modulus of rupture (MoR) for different board treatments.

[0498] Figure 15c shows the internal bond strength (IB) for different board treatments.

[0499] Figure 15d shows the swelling ratio (SB) at 24 h for different board treatments.

[0500] Consideration The results show that the highest concentration of isocyanate (Sample 4) gave the best mechanical performance (MoE and MoR). This board contained 90% by weight of lignocellulosic material. The mixing of the thermoplastic dispersion with the isocyanate gave excellent dispersion throughout the board, resulting in high strength.

[0501] The internal bond strength is determined by the interaction between the lignocellulosic fibers and the binder containing the thermoplastic dispersion. Optimum performance, a strength of 1.19 MPa, was achieved with 10% binder and 2% isocyanate. A relatively high isocyanate content improves adhesion between the wood fibers and the binder.

[0502] The swelling ratio of wood particleboards depends on the wood chip content. Figure 15d shows that the swelling ratio increases with increasing wood chip content and decreasing binder. This is partly because the binder reduces porosity and therefore increases water resistance within the board. The isocyanate content significantly contributes to the mechanical strength of the board.

Claims

1. 1. A method for producing a thermoplastic binder, comprising: as a functionalized thermoplastic that has been processed by sufficiently melting a thermoplastic in an extruder to form an extruder melt zone and reacting the thermoplastic with a coupling agent in the extruder; or as a thermoplastic dispersion processed by sufficiently melting a thermoplastic in an extruder to form an extruder melt zone, followed by dispersing the thermoplastic in water with agitation in an extruder emulsification zone; or ・ The thermoplastic is sufficiently melted in the extruder to form an extruder melt zone; reacting said thermoplastic with a coupling agent in an extruder to form a functionalized thermoplastic; Then, dispersing the functionalized thermoplastic in water with stirring in an emulsification zone of the extruder. as a dispersion of functionalized thermoplastics treated by Obtaining a treated thermoplastic; and thereafter adding a crosslinking agent to the treated thermoplastic to produce a binder; A method comprising:

2. providing a source of thermoplastic; introducing said thermoplastic into the inlet end of one or more extruders; melting said thermoplastic sufficiently in said one or more extruders to form a melt zone; 1. A method for producing a thermoplastic composite product, comprising: a) reacting at least a portion of the thermoplastic with a coupling agent to form a functionalized thermoplastic; or b) dispersing the thermoplastic in water with stirring to form a thermoplastic dispersion; or c) performing (a) followed by (b) to produce a dispersion of a functionalized thermoplastic; and thereafter adding a crosslinking agent to the functionalized thermoplastic or the thermoplastic dispersion by adding a crosslinking agent to the extruder or to the extruded functionalized thermoplastic or thermoplastic dispersion to form a binder; and mixing the binder with a substrate in fibrous form to form a composite mixture, and applying heat and pressure to the composite mixture in a press or mold to form a thermoplastic composite article; A method comprising:

3. 3. The method of claim 1 or 2, wherein the extruder is a twin-screw extruder.

4. 4. The method of any one of claims 1 to 3, wherein the thermoplastic source comprises a high melting point thermoplastic, such as polypropylene, and a low melting point thermoplastic, such as polyethylene, or a combination thereof.

5. 5. The method of claim 4, wherein the ratio of high melting point thermoplastic to low melting point thermoplastic is from 1:4 to 4:

1.

6. The method of any one of claims 1 to 5, wherein the source of thermoplastic comprises waste thermoplastic.

7. For the thermoplastic plastic, a) increasing the melt flow index of said thermoplastic; b) washing said thermoplastic; c) milling the thermoplastic to reduce particle size variation of the thermoplastic; d) standardizing the particle size and / or density; e) pelletizing to a particle size of 2-8 mm; or f) Any combination of one or more of (a) to (e). The method according to any one of claims 1 to 6, wherein a pretreatment step comprising:

8. 8. The method of any one of claims 1 to 7, wherein the thermoplastic is subjected to a characterization step in which one or more physical properties of the thermoplastic are analyzed.

9. 9. The method of any one of claims 1 to 8, wherein the thermoplastic is subjected to a pre-treatment step, and increasing the melt flow index of the thermoplastic comprises processing the thermoplastic through an extruder.

10. 10. The method of any one of claims 1 to 9, including the pre-treatment step, wherein increasing the melt flow index of the thermoplastic comprises adding a melt flow increasing additive to the extruder.

11. 11. The method of claim 10, wherein the melt flow increasing additive is selected from plasticizers, initiators, and combinations thereof.

12. 12. The method of any one of claims 1 to 11, including the pre-treatment step, wherein increasing the melt flow index of the thermoplastic comprises adding another thermoplastic having a higher melt flow index.

13. 13. The method of any one of claims 1 to 12, comprising the characterization step, wherein the physical property of the thermoplastic is selected from the melt flow index, melting point, viscosity, glass transition temperature, density, tensile strength, or crystallinity of the thermoplastic.

14. The method of any one of claims 1 to 13, wherein the coupling agent is selected from a grafted compatibilizer or a reactive hydrogen donor.

15. The method of any one of claims 1 to 14, wherein the coupling agent is selected from glycidyl methacrylate, maleic anhydride, acrylic acid, glycidyl methacrylate, N-vinyl formamide, bismaleimide, or a silane.

16. 16. The method of any one of claims 1 to 15, wherein at least a portion of the thermoplastic is reacted with an initiator in the extruder.

17. A method according to any one of the preceding claims, wherein the thermoplastic is dispersed in water by the addition of a surfactant.

18. The method according to any one of claims 1 to 17, wherein the crosslinking agent is selected from an organic peroxide or an isocyanate.

19. The method of claim 18, wherein the isocyanate is added in an amount of 5% to 20% by weight of the binder.

20. 20. The method of claim 18 or 19, wherein the isocyanate is a blocked isocyanate.

21. The method of any one of claims 18 to 20, wherein the isocyanate is a diisocyanate.

22. 21. The method of claim 20, wherein the blocked isocyanate is added to the extruder cooled to a temperature below the unblocking temperature of the isocyanate blocking agent.

23. The method of any one of claims 1 to 22, wherein the moisture content of the binder is from about 25% to about 75%.

24. 24. The method of any one of claims 1 to 23, wherein the emulsification zone includes a dilution zone for adding additional water to provide a thermoplastic to water ratio of about 0.8:1 to 1.8:

1.

25. The method of any one of claims 2 to 24, wherein the binder and the substrate fibers are mixed in a mixer to form a substantially homogeneous mixture.

26. 26. The method of any one of claims 2 to 25, wherein the substrate fibers are selected from glass fibers, carbon fibers, aramid fibers, and combinations thereof.

27. 27. The method of any one of claims 2 to 26, wherein the substrate fibers are selected from lignocellulosic materials selected from sawdust, wood fibers, wood particles, wood chips, wood sheets, coconut shells, rice or rice straw, barley straw, bamboo, and combinations thereof.

28. 28. The method of any one of claims 2 to 27, further comprising forming a thermoplastic composite article, wherein the composite mixture has a moisture content of about 5% to about 15%.

29. 29. A method according to any one of the preceding claims, wherein the plastic particles in the thermoplastic dispersion or binder have a particle size in any direction or axis of less than 0.5 mm in length.

30. 30. The method of any one of claims 1 to 29, wherein the temperature of the melt zone is from about 140°C to about 240°C and the temperature of the subsequent zone is lower than the temperature of the melt zone.

31. 32. The method according to any one of claims 1 to 31, wherein the degree of functionalization of the binder is between 0.5% and 6%.

32. The characteristic evaluation step a) establishing a predetermined range of the melt flow index of the thermoplastic; b) processing said thermoplastic through said extruder; c) measuring the melt flow index of the treated thermoplastic; d) comparing the measured melt flow index with a predetermined range of melt flow indices; e) adjusting one or more conditions of the extruder so that the melt flow index of the processed thermoplastic is within the predetermined range, the one or more conditions comprising: - the ratio of different types of thermoplastics, - processing said thermoplastics in an extruder; - the proportion of PP in the thermoplastic; the amount of plasticizer added to the thermoplastic; - extruder zone temperatures, the degree of agitation within the extruder, or the residence time of the thermoplastic in the extruder; Any combination of, or selected from one or more of; 33. The method of any one of claims 1 to 32, comprising:

33. a) lignocellulosic thermoplastic composite products; b) Synthetic fiber composite products; or c) Concrete composite products The method according to any one of claims 2 to 32 in the manufacture of

34. a) an elastic modulus of about 1,000 to about 4,000 MPa b) a modulus of rupture of about 10 to about 25 MPa c) a screw retention force of about 200 to about 500 N d) Approximately 550 to approximately 1,100 kg / m ３ density of, or e) any combination of one or more of (a) to (d).

34. The method of any one of claims 2 to 33 in the manufacture of a lignocellulosic thermoplastic composite board having

35. a) waste thermoplastics; b) lignocellulosic material; and c) Crosslinking Agent 1. A composite board comprising: A composite board, wherein the lignocellulosic material comprises at least 75% of the composite board.

36. 36. The composite board of claim 35, wherein the crosslinking agent comprises an organic peroxide or an isocyanate-based crosslinking agent.

37. 37. The composite board of claim 35 or 36, wherein the waste thermoplastic comprises at least one of waste polyethylene or waste polypropylene.

38. a) MoR greater than 1000 MPa; b) MoE greater than 8 MPa; c) an IB greater than 0.2; d) a moisture content greater than about 5%; or e) a moisture content of less than about 15% 38. A composite board according to any one of claims 35 to 37, comprising at least one of:

39. A thermoplastic dispersion comprising a functionalized waste thermoplastic and water, the thermoplastic comprises at least one of a high melting point thermoplastic, such as polypropylene, and a low melting point thermoplastic, such as polyethylene; the water is present in the dispersion at about 25% to 75%; Thermoplastic dispersions.

40. 40. The thermoplastic dispersion of claim 39, further comprising at least one surfactant.

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