Home compostable colour masterbatch

Abstract

A home compostable colour masterbatch and a process for making the same are provided. The colour masterbatch includes a colorant and an amphiphilic biodegradable polymer matrix selected from the group consisting of PBAT-PEG, PHA-PEG, PCL-PEG, TPS-PHA, PBSA- PEG, TPS-PBAT, and TPS-PBS. The colour masterbatch does not contain polylactic acid. The colorant and the amphiphilic biodegradable polymer matrix to form a mixture. The mixture is heated and torqued at a processing temperature sufficient to melt the amphiphilic biodegradable polymer matrix to make the colour masterbatch.

Description

HOME COMPOSTABLE COLOUR MASTERBATCHTechnical Field

[0001] The present invention relates to relates in general to a home compostable colour masterbatch and a process for making the same.Background

[0002] A masterbatch is typically a granular, dust-free concentrate of a plastomeric or elastomeric polymer comprising a fraction of a colorant. Masterbatches are used to colour plastics, being added to the plastic to be colored prior to or during processing. Colour masterbatches are commonly employed for colouration when processing plastics because they provide better colorant dispersion than powdery colorant. In addition, the use of powdery colorant in plastics can lead to airborne dispersion, potentially affecting operator’s health and environmental cleanliness during mixing and addition processes.

[0003] The following steps are standard in the production of colour masterbatches: (i) mixing a carrier (polymers) with a colorant; (ii) extruding and kneading with subsequent grinding of the mixture; or (iii) extrusion and subsequent fine spraying, hot chopping, or strand pelletizing.

[0004] A colour masterbatch generally includes a colorant, a carrier (polymer), a dispersant, and optionally one or more additives. A typical formulation of a masterbatch may include about 30% by weight of a colorant, about 55% by weight of a carrier, about 5% by weight of dispersant, and about 10% by weight of additive.

[0005] The carrier is often conventional polymers, such as linear low-density polyethylene and low-density polyethylene, which would render the end product non-biodegradable and / or non-compostable. To ensure the biodegradability and / or compostablity of the end product, both the colorant and its carrier need to be biodegradable. The development of efficient and user-friendly colouration methods for bio-based degradable plastics remains an ongoing consideration.

[0006] The foregoing examples of the related art and limitations related thereto are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specification and a study of the drawings.Summary

[0007] The following embodiments and aspects thereof are described and illustrated in conjunction with systems, tools and methods which are meant to be exemplary and illustrative, not limiting in scope. In various embodiments, one or more of the above-described problems have been reduced or eliminated, while other embodiments are directed to other improvements.

[0008] The present invention has a number of aspects. These aspects include without limitation:• a colour masterbatch; and• a method of making a colour masterbatch.

[0009] In one aspect, a new and useful colour masterbatch is provided. Without being bound by theory, some advantages that may be provided by some embodiments of the biodegradable polymer composite include that:• the colour masterbatch contains no PLA;• the colour masterbatch is home compostable;• the colour masterbatch exhibits chemical and physical interaction with a wide range of polar, non-polar, hydrophilic, and hydrophobic polymers;• the colour masterbatch is universally compatible with polar, non-polar, hydrophilic, and hydrophobic polymers, enabling its integration into diverse polymer matrices;• the colour masterbatch includes a pH-sensitive and temperature-responsive colorant, resulting in observable colour changes; and• the colour masterbatch includes a self-healing mechanism.

[0010] Another aspect provides a method for making a colour masterbatch. A colorant is mixed with an amphiphilic biodegradable polymer matrix to form a mixture, wherein the amphiphilic biodegradable polymer matrix is selected from the group consisting of PBAT- PEG, PHA-PEG, PCL-PEG, TPS-PHA, PBSA-PEG, TPS-PBAT, and TPS-PBS. The mixture is heated and torqued at a processing temperature sufficient to melt the amphiphilic biodegradable polymer matrix to make the colour masterbatch. The colour masterbatch does not contain polylactic acid (PLA) is home compostable.

[0011] In some embodiments, a grafted polymer selected from the group consisting of maleic anhydride grafted PBAT, PBS, PHA, and PBSA is also added to the mixture.

[0012] The colorant and the amphiphilic biodegradable polymer matrix may be mixed with a mixing speed of about 40-100 rpm and at a mixing temperature not exceeding 80°C.

[0013] The mixture may be extruded via a twin-screw extruder with a screw speed of about 150-450 rpm and having a screw with a length-to-diameter ratio ranging from 37:1 to 50:1 and a diameter ranging from 18 mm to 120 mm. In addition, the mixture may pass through the twin-screw extruder from a first zone with a temperature of about 85-95°C, to a second zone with a temperature of about 170-180°C, to a third zone with a temperature of about 180- 200°C, to a fourth zone with a temperature of about 180-210°C, and to a fifth zone with a temperature of about 170-200°C.

[0014] The colour masterbatch may be cooled and pelletized.

[0015] The colorant may be anthocyanin, thermochromic pigment, hydrochromic ink, fluorescein, leuco dye, or polydiacetylene with the ability to change colour in response to variations in pH and temperature.

[0016] The mixture may include modified nanoparticles. Nanoparticles, such as silver nanoparticles, single-walled carbon nanotubes, carbon nanofibers, nanohydroxyapatite, nanocellulose, nanolignin, montmorillonite, graphene oxides, silica, kaolin clay, calcium carbonate, bentonite clay, cloisite clay, mica, wollastonite, or halloysite, may react with a grafting agent so that surfaces of nanoparticles are modified. The grafting agent may becetyltrimethylammonium bromide (CTAB), hexadecylpyridinium chloride (HPC), sodium dodecyl sulfate (SDS), sodium oleate, Triton X-100™, polysorbate 80 (Tween 80™), dodecyldimethylamine oxide (DDAO), cocamidopropyl betaine, aminopropyltriethoxysilane (APTES), methacryloxypropyltrimethoxysilane (MPS), mercaptosilanes, epoxysilanes, citric acid, acrylic acid, oleic acid, organic acid, stearic acid, tetraalkoxy titanates, aluminum alkoxides, zirconium alkoxides, hexamethylene diisocyanate (HDI), maleic anhydride, aryl diazonium salts, glycidyl methacrylate (GMA), mercaptosilanes, or phosphonic acid derivatives.

[0017] The mixture may include a cross-linking agent, an enzyme, an anti-microbial agent, an anti-microbial agent, and / or a UV stabilizer.

[0018] The mixture may include a microcapsule containing a healing agent to the mixture. The healing agent may be chitosan, alginate, a cellulose derivative, gelatin, or a combination thereof. When the microcapsule ruptures, the healing agent is released and interacts with the amphiphilic biodegradable polymer matrix to initiate a self-repair process.

[0019] Another aspect provides a colour masterbatch that contains a colorant and an amphiphilic biodegradable polymer matrix selected from the group consisting of PBAT-PEG, PHA-PEG, PCL-PEG, TPS-PHA, PBSA-PEG, TPS-PBAT, and TPS-PBS. The colourmasterbatch does not contain polylactic acid (PLA) and the colour masterbatch is home compostable.

[0020] The colour masterbatch may include a grafted polymer selected from the group consisting of maleic anhydride grafted PBAT, PBS, PHA, and PBSA.

[0021] The colorant may be anthocyanin, thermochromic pigment, hydrochromic ink, fluorescein, leuco dye, or polydiacetylene with the ability to change colour in response to variations in pH and temperature.

[0022] The colour masterbatch may include a nanoparticle whose surfaces are modified using a grafting agent. The nanoparticle may be silver nanoparticles, single-walled carbon nanotubes, carbon nanofibers, nanohydroxyapatite, nanocellulose, nanolignin, montmorillonite, graphene oxides, silica, kaolin clay, calcium carbonate, bentonite clay, cloisite clay, mica, wollastonite, or halloysite, the surfaces of which are modified using a grafting agent selected from the group consisting of cetyltrimethylammonium bromide (CTAB), hexadecylpyridinium chloride (HPC), sodium dodecyl sulfate (SDS), sodium oleate, Triton X-100™, polysorbate 80 (Tween 80™), dodecyldimethylamine oxide (DDAO), cocamidopropyl betaine, aminopropyltriethoxysilane (APTES), methacryloxypropyltrimethoxysilane (MPS), mercaptosilanes, epoxysilanes, citric acid, acrylic acid, oleic acid, organic acid, stearic acid, tetraalkoxy titanates, aluminum alkoxides, zirconium alkoxides, hexamethylene diisocyanate (HDI), maleic anhydride, aryl diazonium salts, glycidyl methacrylate (GMA), mercaptosilanes, and phosphonic acid derivatives.

[0023] The colour masterbatch may include a cross-linking agent, an enzyme, an antimicrobial agent, an anti-microbial agent, and / or a UV stabilizer.

[0024] The colour masterbatch may include a microcapsule containing a healing agent. The healing agent may be chitosan, alginate, a cellulose derivative, gelatin, or a combination thereof. When the microcapsule ruptures, the healing agent is released and interacts with the amphiphilic biodegradable polymer matrix to initiate a self-repair process.

[0025] Another aspect provides a method for making a colourized biodegradable polymer. A colour masterbatch is introduced to a melt-processible biodegradable polymer to form a processable polymer composition, wherein the colour masterbatch comprises a colorant and an amphiphilic biodegradable polymer matrix selected from the group consisting of PBAT- PEG, PHA-PEG, PCL-PEG, TPS-PHA, PBSA-PEG, TPS-PBAT, and TPS-PBS. The processable polymer composition is processed, to form the colourized biodegradable polymer.

[0026] In addition to the exemplary aspects and embodiments described above, further aspects and embodiments will become apparent by reference to the drawings and by study of the following detailed descriptions.Brief Description of the Drawings

[0027] Exemplary embodiments are illustrated in referenced figures of the drawings. It is intended that the embodiments and figures disclosed herein are to be considered illustrative rather than restrictive.

[0028] FIG. 1 A is morphological analysis of hemp residue, FIG. 1 B is a FTIR spectra for hemp residue, FIG. 1C is thermogravimetric data of hemp residue, and FIG. 1 D is derivative weight loss data of the hemp residue.

[0029] FIG. 2 is FTIR spectra of PBAT before (lower) and after (upper) MA grafting.

[0030] FIGS. 3A-3B depict DSC thermograms of the PBAT and its biodegradable polymer composites at different hemp residue content levels and the presence of MA. FIG. 3A depicts heating curves and FIG. 3B depicts Cooling curves.

[0031] FIG. 4A-4B depict the results of TGA study of the biocomposites in accordance with embodiments of the present invention. FIG. 4A depicts percent weight loss of prepared specimens, without mPBAT against temperature, and FIG. 4B depicts percent weight loss of prepared specimens with mPBAT against temperature.

[0032] FIGS. 5A-5D depict the results of tensile testing of the exemplary biocomposites in accordance with embodiments of the present invention. FIG. 5A depicts mechanical strength and elongation at break; FIG. 5B depicts tensile modulus and toughness; and FIG. 5C depicts corresponding stress-strain curve of developed biocomposites, and FIG. 5D depicts effect of HP on heat deflection temperature of biocomposites.

[0033] FIGS. 6A-6D depict effect of temperature on specimen load bearing capability, wherein FIGS. 6A and 6B depict storage modulus of the biocomposite in accordance with an embodiment of the present invention without and with mPBAT, and FIGS. 6C and 6D depict tan delta of the biocomposite without and with mPBAT.

[0034] FIGS. 7A-7C depict rheological properties of PBAT and its biocomposites with and without the presence of MA in accordance with embodiments of the present invention. FIG. 7A depicts complex viscosity, FIG. 7B depicts storage modulus, and FIG. 7C depicts loss modulus.

[0035] FIG. 8A is SEM micrographs of hemp powder, FIG. 8B depicts fractured surfaces of neat PBAT, FIG. 8C depicts fractured surface of PBAT-10HP biocomposite in accordance with an embodiment of the present invention, and FIG. 8D depicts fractured surface of PBAT- 40HP biocomposite in accordance with an embodiment of the present invention.

[0036] FIGS. 9A-9D depict SEM micrographs of different magnifications of fractured surfaces of PBAT-40HP at (a) 500X and (b) 1000X; and fractured surfaces of PBAT-40HP-M at (c) 500X and (d) 1000X.

[0037] FIG. 10 depicts gel content in developed biocomposite due to the presence of mPBAT.

[0038] FIG. 11 depicts representative cutlery and flexible sheets prepared by compression molding using PBAT-40HP-M biocomposite in accordance with an embodiment of the invention.

[0039] FIGS. 12A-12E show the composting process of a film made from a biocomposite in accordance with an embodiment of the present invention.

[0040] FIG. 13 shows the temperature evolution during a composting process, wherein two control bins are labelled CDI-3 / 3-01 and CDI-3 / 3-02 and two test bins are labelled CDI-3 / 3- 03 and CDI-3 / 3-04.

[0041] FIG. 14 shows the CO2 production rate during the composting test as shown in FIG. 13.

[0042] FIG. 15 shows the oxygen concentration of the exhaust air during the composting test as shown in FIG. 13.

[0043] FIG. 16 shows the evolution of the pH during a composting test, wherein two control bins are labelled CDI-3 / 3-01 and CDI-3 / 3-02 and two test samples are labelled CDI-3 / 3-03 (Earth Edition) and CDI-3 / 3-04 (Earth Edition).

[0044] FIG. 17 shows the trend in NH4+-N for the different bins during the composting test as shown in FIG. 16.

[0045] FIG. 18 shows the trend in NOx'-N for the different bins during the composting test as shown in FIG. 16.

[0046] FIGS. 19 shows representative colour masterbatches (in white, blue, yellow, pink, or black) in accordance with an embodiment of the invention.

[0047] FIG. 20A-20E show representative cutlery and straws prepared by compression molding using the colour masterbatches shown in FIG. 19 and biodegradable polymer.Description

[0048] Throughout the following description specific details are set forth in order to provide a more thorough understanding of the present invention to persons skilled in the art. Well- known elements may not have been shown or described in detail to avoid unnecessarily obscuring the disclosure. The description and drawings are to be regarded in an illustrative, rather than a restrictive, sense.

[0049] Various chemical substances are described herein. Such chemical substances may not be absolute pure. Instead, such substances may have a purity of at least about 50%, at least about 60%, at least about 70%, at least about 80%, at least about 90%, at least about 95%, at least about 97%, at least about 98%, or at least about 99% pure. The expression “substantially pure” means a purity of greater than 95%. For example, “substantially pure” PBAT preparation means that the preparation having a chromatographic purity of greater than 95%, 96%, 97%, 98% or 99%.

[0050] As used herein, the terms “about” or “approximately” mean a value within + / - 10% of the stated value unless specified otherwise. Either one of these terms “about” or “approximately” connotes that strict compliance with the numeric value recited is not critical. Some variation is permissible and still within the scope of the various embodiments described herein.

[0051] As used herein, the term “bio-based” is used in contrast with “petroleum-derived” and the term “bio-based” refers to composites that are manufactured from biological resources instead of being made from fossil raw materials.

[0052] As used herein, the term "biodegradable" refers to a material that degrades or breaks down upon exposure to sunlight or ultra-violet radiation, water or dampness, microorganisms such as bacteria and fungi, enzymes or wind abrasion within 12 months in a compost environment and in a non-toxic, environmentally compatible manner with no heavy metal content, no PTFE content, and remaining soil safe. In some instances, rodent, pest, or insect attack can also be considered as forms of biodegradation or environmental degradation.

[0053] As used herein, the term “biopolymer” refers to polymers that are bio-based, biodegradable or both.

[0054] As used herein, the term “compostable” refers to a material that can decompose in industrial composting facilities. In order for a plastic to be labeled as commercially “compostable”, it would typically be broken down by biological treatment at a commercial or industrial composting facility in 180 days or less. Composting utilizes microorganisms,agitation, heat, and humidity to yield carbon dioxide, water, inorganic compounds, and biomass that is similar in characteristic to the rest of the finished compost product. ASTM Standards D6400 and D6868 outline the specifications that must be met in order to label a plastic as commercially “compostable.”

[0055] As used herein, the term “home compostable” refers to a material that meets the criteria of being biodegradable under home compost conditions (ambient temperature of 25±5° C) and decomposes to over 90% by weight into CO2 and water within 360 days, adhering to the Australian Standard AS 5810-2010 for "Biodegradable plastics suitable for home composting."

[0056] Biodegradable and compostable plastics may be made from biological resources or fossil raw materials.

[0057] As used herein, the term “hydrophobic” means a material having a water contact angle at room temperature greater than 90° and the “hydrophilic” means a material having a water contact angle at room temperature less than 90°.

[0058] As used herein, the term "nano-particle" refers to a particle wherein the particle size in the 1-500nm range. The term "micro-particle" refers to a particle wherein the particle size is in the 500-2, OOOnm range. A nano-particle may be a nano-filler and a micro-particle may be a micro-filler.

[0059] Terms indicating a high frequency, such as (but not limited to) “common”, “typical”, and “usual” as well as “commonly”, “typically,” and “usually” are used herein to refer to features that are often employed in the invention and, unless specifically used with reference to the prior art, are not intended to mean that the features are present in the prior art, much less that those features are common, usual, or typical in the prior art.Biodegradable Polymer Composites- General Embodiments

[0060] Some embodiments of the present invention relate to a biodegradable polymer composite which includes a filler, a polymer, and one or more additives, including an antioxidant, a compatibilizer, a chain extender, a friction modifier, a grafting agent, a lubricant, a heat stabilizer, a nucleating agent, a pigment, a plasticizer, a thermal stabilizer, and / or a UV resistant additive, wherein the biodegradable polymer composite excludes PLA.

[0061] Depending on the applicable use application, for example, whether the application requires that the biodegradable polymer composite to have temperature resistance, physical strength, and elongation properties, the biodegradable polymer composite may includedifferent components. For example, if the use application is for a low temperature environment, the biodegradable polymer composite may include polymers that possess inherent strength and flexibility at low temperatures. The biodegradable polymer composite may incorporate additives to enhance the mechanical and other properties. In some embodiments, the use application requires good heat-sealing characteristics and this may be achieved through the inclusion of certain fillers and additives, such as compatibilizers and chain extender. Certain fillers and additives may facilitate the adhesion between layers during heat sealing processes, resulting in reliable and efficient seals. In some embodiments, printability may be desirable. In such embodiments, the biodegradable polymer may have polar surface with high surface energy that permits ink adhesion and minimizes smudging or fading. The choice of polymers with good printability characteristics, such as suitable surface energy and smoothness, can also contribute to the printability of the material.

[0062] In addition to the selection of appropriate components, the manufacturing process can also impact the mechanical, physical, and chemical properties of the biodegradable polymer composite. For example, controlled extrusion conditions and precise blending methods may be used to control the dispersion of additives.

[0063] Some advantages that may be provided by some embodiments of the biodegradable polymer composite include that:• The biodegradable polymer composites can be used for flexible, semi-rigid, and rigid applications.• The biodegradable polymer composites may have a melt flow index of 0.5 to less than 5 g / 10 min.• The biodegradable polymer composites may have a moisture content of less than 0.1 %.• The biodegradable polymer composites may permit minimal migration, ensuring the integrity of the final use application.• The biodegradable polymer composites may have a shrinkage rate of less than 0.5, providing better dimensional stability during molding.• The biodegradable polymer composites and the products made thereof exhibit stability at ultra-low temperatures.• The biodegradable polymer composites and the products made thereof may meet the food safe requirements as set out by Health Canada.• The biodegradable polymer composites and the products made thereof may biodegrade completely within 12 weeks in under home composting conditions.• The biodegradable polymer composites and the products made thereof may not contain any heavy metals.• The biodegradable polymer composites exhibit an elongation capability of 342% and an impact strength of 323 j / m.• The biodegradable polymer composites do not contain PLA.

[0064] Filler refers to a material that interacts physically or chemically with the polymer when being incorporated with the polymer, thereby modifying the mechanical properties of the polymer. When used, the filler is typically selected to impart useful characteristics to the biodegradable polymer composites, such as, for example addition of the filler may allow for modification of the Young's modulus (psi), %-elongation, and stress at break (“psi”).

[0065] In some embodiments, the filler includes various waste materials. Some advantages that may be provided by such embodiments of the biodegradable polymer composites include that such embodiments provide a solution to address critical challenges in waste management and sustainable resource utilization, particularly in the context of environmental sustainability. By harnessing the potential of organic and / or inorganic waste materials as a filler, in combination with biodegradable polymers, such embodiments offer a sustainable approach to address environmental challenges. In this regard, the filler may be characterized as renewable, by-products from other industries.

[0066] In some embodiments, various waste materials, which may be inorganic and / or organic residues, are integrated with biodegradable polymers, resulting in the production of useful biodegradable polymer composites while simultaneously reducing the strain on landfills and promoting a circular economy. This can help reducing reliance on virgin resources and mitigating environmental impact, thereby paving the way for a more sustainable future. The various waste materials may include hemp stalks, seashells, lignin, sawdust, wood powder, tailings, and limestone.

[0067] For example, hemp stalks, despite possessing remarkable mechanical properties, are frequently overlooked or underutilized within the cannabis industry. Similarly, seashells, commonly considered as waste in the seafood industry, possess inherent properties and applications that have yet to be fully explored. Lignin, an intricate polymer abundant in plant cell walls, often goes to waste during pulp and paper manufacturing, despite its significant potential. Likewise, sawdust and wood powder, byproducts of timber processing, have beenlargely undervalued in terms of their inherent worth. Additionally, the agricultural sector generates substantial quantities of waste, including crop residues, fruit peels, and husks, which are frequently left unused. Furthermore, in the mining industry, tailings, and limestone are often discarded without recognizing their potential as reinforcing agents. Some embodiments of the present invention help unlock the untapped capabilities of these diverse waste materials, thereby creating valuable resources and contributing to sustainable practices across various industries.

[0068] In some embodiments, the waste materials includes hemp, pine, sawdust, eucalyptus, limestone, seashell, tailing, rice husk, and fly ash.

[0069] The inventors made certain observations about some waste materials as a filler as summarized in Table 1.Table 1. Certain Properties of Waste Materials as Fillers.

[0070] In some embodiments, the filler includes calcium carbonate, talc, milled glass, short glass fibers, diatomaceous earth, quartz, silica, kaolin clay, bentonite clay, cloisite clay, mica, or wollastonite.

[0071] The amount of the filler in the biodegradable polymer composite is in the range of about 0.5% to about 50% by weight (by wt), including any value therebetween, e.g. about 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, 10%, 10.5%, 11 %, 11.5%, 12%, 12.5%, 13%, 13.5%, 14%, 14.5%, 15%, 15.5%, 16%,16.5%, 17%, 17.5%, 18%, 18.5%, 19%, 19.5%, 20%, 20.5%, 21 %, 21.5%, 22%, 22.5%, 23%, 23.5%, 24%, 24.5%, 25%, 25.5%, 26%, 26.5%, 27%, 27.5%, 28%, 28.5%, 29%, 29.5%, 30%, 30.5%, 31 %, 31.5%, 32%, 32.5%, 33%, 33.5%, 34%, 34.5%, 35%, 35.5%, 36%, 36.5%, 37%, 37.5%, 38%, 38.5%, 39%, 39.5%, 40%, 40.5%, 41%, 41.5%, 42%, 42.5%, 43%, 43.5%, 44%, 44.5%, 45%, 45.5%, 46%, 46.5%, 47%, 47.5%, 48%, 48.5%, 49% and 49.5%.

[0072] The ratio of the filler to the polymer may vary depending on the desired use applications (e.g. flexible articles, including packaging, construction, transportation, consumer goods), the chemical and physical characteristics of the filler, the chemical and physical characteristics of the polymer, and the conditions used to prepare the biodegradable polymer composite. For example, the biodegradable polymer composite may be used in a transparent film application. The transparent film typically has a high degree of transparency and clarity. There might be a threshold for the amount of filler in the biodegradable polymer composite, wherein if the amount is above the threshold, the resulting transparent film may not have the desirable degree of clarity. In another example, the inventors have determined that the amount of filler in a biodegradable polymer composite can affect the cooling process. For example, the inventors have identified a specific range of the amount of filler in the biodegradable polymer composite, wherein adding fillers to that range helps with the cooling process, thereby reducing the cycle time. In a further example, the inventors have noticed that the amount of filler in a biodegradable polymer composite can affect processability during compounding and use applications. As a general observation, the inventors note that an increase in the filler content in a biodegradable polymer composite up to a threshold can improve the tensile and flexural property of the biodegradable polymer composite. However, beyond that threshold, depending on the method of processing, the adhesion between the polymer and the filler decreases resulting in the decrease in the strength of final products. The inventors note that filler percentage can affect crystallinity and biodegradation of the final product. In some cases, filler percentage can affect the overall appearance and quality of the final product.

[0073] Fillers may be of different shapes (e.g., spherical, rectangular, triangular, cylindrical, tubular, fibrous, platelet, flake).

[0074] Fillers may be of sizes. For example, fillers may have a median particle size of from 0.1 pm to 10 pm, optionally from 0.25 pm to 8 pm, optionally from 0.5 pm to 6 pm, optionally from 0.75 pm to 4 pm, or optionally from 0.8 pm to 2 pm (e.g., 1.5 pm). In some embodiments,the particle sizes of the filler are in the 1-500nm range. In some embodiments, the particle sizes of the filler are in the 500-2, OOOnm range.

[0075] With respect to the polymer, the polymer is biodegradable polymer, which may be PBAT, PBS, polycaprolactone (PCL), poly(butylene succinate-co-terephthalate) (PBST), Poly(butylene succinate-co-butylene adipate) (PBSA), polyglycolic acid (PGA), cellulose acetate (CA), thermoplastic starch (TPS), or polyhydroxyalkanoates (PHA). As used herein, the term "thermoplastic starch" (TP starch) refers to starch blended with suitable plasticizer(s).

[0076] The polymer may be a grafted polymer. In some embodiments, the grafted polymer is formed combining a polymer selected from a group consisting of polybutylene adipate terephthalate (PBAT), polybutylene succinate (PBS), polyhydroxyalkanoates (PHA), and polycaprolactone (PCL) with a compatibilizer selected from a group consisting of maleic anhydride, glycidyl methacrylate, pyromellitic anhydride, acrylic acid, polyacrylic acid, methylene diphenyl diisocyanate, poly(glycidyl methacrylate, copolymer(s) of glycidyl methacrylate and / or copolymers of acrylic acid to form a reaction mixture and melting the reaction mixture to form the grafted polymer.

[0077] In some embodiments, the grafted polymer may be about 30 to 99.5% by weight of a polymer selected from a group consisting of polybutylene adipate terephthalate (PBAT), polybutylene succinate (PBS), polyhydroxyalkanoates (PHA), and polycaprolactone (PCL) grafted with a compatibilizer selected from a group consisting of maleic anhydride, glycidyl methacrylate, pyromellitic anhydride, acrylic acid, polyacrylic acid, methylene diphenyl diisocyanate, poly(glycidyl methacrylate, copolymer(s) of glycidyl methacrylate and about 0.5 to 50 % by weight a nano-filler or a micro-filler. The composition does not contain polylactic acid (PLA).

[0078] In some embodiments, the polymer includes, one or more of PBAT, PBS, PBSA, PBST, BIO-PBS, BIO-PBSA, BIO-PBST, PCL, TPS, polyhydroxybutyrate (PHB), poly(3- hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), poly[(R)-3-hydroxybutyrate-co-4- hydroxybutyrate] (P3HB4HB), cellulose acetate, cellulose acetate butyrate, cellulose acetate proporiante, poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBH), poly(glycolic acid) (PGA), chitin, chitosan or combinations thereof.

[0079] The inventors have made certain observations about the tensile properties of polymers as set out in Table 2. The tensile properties with an elongation at break in tensile mode below15% was at test conditions of 10 mm / min. The input “n.o.” indicates that the specific property could not be measured. The standard deviation is given between brackets.Table 2. Tensile Properties of Certain Polymers.

[0080] In some embodiments, the polymer excludes PLA.

[0081] In some embodiments, the polymer excludes PLA and any petroleum-derived polymers.

[0082] The amount of the polymer in the biodegradable polymer composite is in the range of about 30% to about 99.5% (by weight), including any value therebetween, e.g. about 31 %, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39%, 40%, 41 %, 42%, 43%, 44%, 45%, 46%, 47%,48%, 49%, 50%, 51 %, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, 60%, 61 %, 62%, 63%,64%, 65%, 66%, 67%, 68%, 69%, 70%, 71 %, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%,80%, 81 %, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91 %, 92%, 93%, 94%, 95%,96%, 97%, 98%, and 99%.

[0083] In some embodiments, the biodegradable polymer composite includes one or more additives.

[0084] When a compatibilizer is blended with a polymer, generally the hydrolysis of the polymer will be suppressed. Compatibilizers are typically classified into two main categories: (i) reactive compatibilizers containing reactive functional groups (maleic anhydride, epoxy,etc.) that can interconnect different polymer phases by generating chemical bonds between functional groups (hydroxyl, carboxyl, etc.) of the polymer chains; and (ii) non-reactive compatibilizers (typically premade copolymer) that are miscible to all constituents in the polymer blends.

[0085] In some embodiments, the polymer is a home compostable polymer, wherein the polymer exhibits a 90% disintegration completion within 12 weeks in home composting conditions.

[0086] Non-reactive compatibilization involves the utilization of compatibilizing agents, typically in the form of grafted or block copolymers, strategically designed to engage in chemical interactions with the base polymers of the blend. The effectiveness of this technique arises from the dual functionality inherent in copolymers, allowing the compatibilizing agent to establish chemical bonds with both polymers in an otherwise immiscible blend. This interaction leads to the formation of bridges between the polymers, positively influencing their miscibility. Compatibilizers include maleic anhydride grafted PBAT (PBAT-g-MA), ethylene- glycidyl methacrylate copolymer (EGMA), and ethylene-methyl acrylate-glycidyl methacrylate (EMA-GMA) terpolymer. The incorporation of these compatibilizers significantly contributes to reducing domain sizes and enhancing interfacial adhesion, consequently improving the mechanical properties of the blends.

[0087] A chain extender refers to materials having terminal active groups (e.g., OH or NH) that can act as a spacer between one or more monomers to facilitate processing and impart the required properties (e.g., strength or electrical and frictional properties). Also, chain extenders can be used to activate the ending groups of polyesters to initiate the polymerization process so that increases the number of monomers being polymerized and the molecular weight of the polymers.

[0088] In some embodiments, the chain extender includes diphenylmethane diisocyanate (MDI), toluene diisocyanate (TDI), ethylene glycol, propylene glycol, butanediol, ethylenediamine, hexamethylenediamine, butanediol diglycidyl ether (BDGE), polycaprolactone diol (PCL diol), maleic anhydride, glycerol, sorbitol, polyethylene glycol (PEG), citric acid, dicumyl peroxide, t-amyl-2-ethylhexyl peroxycarbonate, 1 ,1-bis(t- butylperoxy)-3,3,5-trimethycyclohexane, 2,5-dimethyl-2,5-di(t-butylperoxy) hexane, 2,5-bis(t- butylperoxy)-2,5-dimethylhexane, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane-3, di-t-butyl peroxide, benzoyl peroxide, di-t-amyl peroxide, t-butyl cumyl peroxide, n-butyl-4,4-bis(t- butylperoxy)valerate, 1 ,1-di(t-butylperoxy)-3,3,5-trimethyl-cyclohexane, 1 , 1 -di(t-butylperoxy)cyclohexane, 1 ,1-di(t-amylperoxy)-cyclohexane, 2,2-di(t-butylperoxy)butane, ethyl-3,3-di(t-butylperoxy)butyrate, 2,2-di(t-amylperoxy)propane, ethyl-3,3-di(t- amylperoxy)butyrate, t-butylperoxy-acetate, t-amylperoxyacetate, t-butylperoxybenzoate, t- amylperoxybenzoate, and poly(ethylene-glycidyl methacrylate-co-methacrylate).

[0089] Nucleating agents function to expedite cycle times for polymers capable of crystallization. The solidification rate of plastic into different form is a determining factor in processing and cycle time. The acceleration of crystallization, facilitated by nucleation, contributes to faster molding cycles or the production of clearer extruded thin films. However, the rapid crystallization process, while economically advantageous, presents potential drawbacks. It is noteworthy that overly fast crystallization may result in small crystal sizes, which is desirable for clear film. However, for some polymers, an eventual increase in crystallite size and a shift in properties may occur over time.

[0090] In some embodiments, the nucleating agent includes carbon black, calcium carbonate, synthesized silicic acid and salts, silica, zinc white, clay, kaolin, basic magnesium carbonate, mica, talc, quartz powder, diatomite, dolomite powder, titanium oxide, zinc oxide, antimony oxide, barium sulfate, calcium sulfate, alumina, calcium silicate, metal salts of organophosphates, boron nitride, octylic acid, toluic acid, heptanoic acid, pelargonic acid, cyanuric acid , lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, cerotic acid, montanic acid, melissic acid, benzoic acid, p-tert-butylbenzoic acid, terephthalic acid, terephthalic acid monomethyl ester, isophthalic acid, isophthalic acid monomethyl ester, 3,3 dimethylbutene-1 ,3-methylbutene-1 ,3-methylpentene-1 ,3-methylhexene-1 , 3,5,5- trimethylhexene-1 , vinylcyclopentane, vinylcyclohexane, vinylnorbornane; diphenyl phosphate, diphenyl phosphite, metal salts of bis(4-tert-butylphenyl) phosphate, methylene bis-(2,4-tert-butylphenyl)phosphate, bis(p-methylbenzylidene) sorbitol and bis(p- ethylbenzylidene) sorbitol, thioglycolic anhydride, p-toluenesulfonic acid, and aluminum hydroxy diphosphate.

[0091] A pro-oxidant in polymer function to make the polymer susceptible to oxidative degradation. In some embodiments, the pro oxidant includes trimethylolpropane, iron stearate, dibismuth oxide, manganese salts, cobalt salts, iron salts, metal soaps, metal chelates, and oligosaccharides.

[0092] An antioxidant, when added to polymer, can slow down degradation caused by thermomechanical or thermos-oxidative conditions. Antioxidants may include amines, phenolics, phosphites, thioesters etc. Virtually all polymeric materials undergo oxidation reactions.Oxidation can occur at every stage of the life cycle of a polymer, i.e. during manufacturing and storage of the material or during processing and end-use. Typical manifestations of oxidation of polymers can be change of viscosity during processing, appearance, and loss of mechanical properties such as elongation, impact strength, tensile strength, and flexibility. Antioxidants protect polymers against oxidation by controlling molecular weight changes that lead to a loss of physical, mechanical, and optical properties. Among other factors heat, light and mechanical stress can result in the degradation of the polymer.

[0093] Antioxidants interrupt the degradation processes in different ways, depending on their structure. The two major classifications are: chain terminating primary antioxidants and hydroperoxide decomposing secondary antioxidants. Primary antioxidants react rapidly with free radicals and are sometimes referred to as “radical scavengers". The majority of primary antioxidants for polymers are sterically hindered phenols. Some of the primary antioxidants are Irganox™ 1010, Irganox™ 1076, Irganox™ 1098, Irganox™ 1330, Irganox™ 245, Irganox™ 1135. Part of primary antioxidants, are aromatic amines, mainly used in polyurethane applications. Irganox™ 5057 is such an aromatic amine for polyol stabilization. Secondary antioxidants, including phosphites and thioesters, react with hydroperoxides to yield non-radical products. They are particularly useful in synergistic combinations with primary antioxidants.

[0094] Phosphites can be effective during processing and protect both the polymer and the primary antioxidant. Thioesters can increase the long-term thermal stability in conjunction with phenolic antioxidants. Irgafos™ 168, Irgafos™ 126, Irganox™ PS 800 and Irganox™ PS 802 are secondary antioxidants. In multifunctional stabilizers, several functions are combined in the same molecule: the most widely used combination are sterically hindered phenols with sulfur substituents or sterically hindered phenols with copper chelating function (metal deactivators). Irganox™ 1035, Irganox™ 565, Irganox™ 1520 L, Irganox MD™ 1024 are examples of multifunctional additives.

[0095] A third class of antioxidants are the radical scavengers. Scavenging the radicals immediately stops the degradation. They are mainly used for extrusion processing. Irganox E™ 201 and the blend Irgastab FS™ 301 belong to this class of antioxidants.

[0096] With respect to anti-oxidants, a biodegradable polymer composite may include an antioxidant coating. Here, a polymer may be mixed and melted with an anti-oxidant to form an anti-oxidant mixture and the anti-oxidant mixture is then used to coat a biodegradable polymer composite. For example, the anti-oxidant may become ineffective under basic conditions,such as in sea water, to cause the grafted polymer to oxidatively degrade. To speed up the degradation process under basic conditions, the composite may include a pro-oxidant. See Example 8.

[0097] The additive may be a processing aid. When incorporated into polymers, a processing aid functions to reduce frictional forces and can enhance the processing and performance characteristics of the compounded material. By reducing the intermolecular interactions between polymer chains, processing aids can improve flowability, melt processing, and overall handling of the compounded material. Processing aids can help make the pellets easier to manipulate in downstream manufacturing processes (such as extrusion, blowing, casting). Adequate amounts of processing aids can help eliminate melt fractures during cast film, blown film, sheet extrusion, pipe extrusion etc. This can be particularly helpful for polymer pellets exhibiting relatively higher viscosity in extrusion processes. Melt fracture is a mechanically-induced melt flow instability which occurs, e.g., at the exit of an extrusion die and typically in conditions of high shear rate. Pinhole, linear, and annular die geometries are among those that can induce melt fracture.

[0098] In polymer compounding, processing aids can provide several benefits:• Improved Processing: processing aids reduce the resistance between polymer particles or melt and processing equipment surfaces, resulting in enhanced flow properties. This allows for easier and more efficient processing during extrusion, injection molding, or other shaping operations.• Enhanced Surface Finish: By minimizing internal friction, these additives can help reduce surface imperfections such as melt fracture, flow marks, or surface roughness, resulting in a smoother and more aesthetically pleasing finish.• Energy Savings: The reduced frictional forces achieved through the use of processing aid can lead to energy savings during processing. Lower energy requirements for melting, mixing, and shaping the polymer compound can translate into cost savings and increased efficiency.• Improved Mechanical Properties: processing aids can also influence the mechanical properties of the final product. By optimizing the polymer flow and reducing internal stresses during processing, they can contribute to improved material strength, impact resistance, and dimensional stability.

[0099] In some embodiments, the processing aids include Pluriol E™ 1500, Pluriol E™ 4000, Pluriol E™ 8000 available from BASF™, Carbowax™ 8000, Carbowax™ Sentry™ 8000 NF EP available from Dow™. HiTerra T5™ from Techmer PM , IP1170, IP 1123, IP 1130, IP 1142, IP 1153 by ingenia™, polysiloxanes, polyether modified siloxanes, and polyethylene glycols etc.

[0100] In some embodiments, the pigment includes titanium dioxide, carbon black, iron oxides, phthalocyanine blue / green, organic reds, quinacridone, inorganic blues, chrome yellow, cadmium, phosphorescent, and barium sulfate.

[0101] A plasticizer refers to a material that exchanges the intermolecular bonds among polymer chains to bonds between the macromolecules and the small molecular weight compound when being incorporated with polymers, thereby promoting conformational changes and resulting in deformability.

[0102] In some embodiments, the plasticizer includes dibutoxyethoxyethyl adipate , dioctyl adipate, diisooctyl adipate, di-n-octyl adipate, didecyl adipate, diisodecyl adipate, n-octyl n- decyl adipate, n-heptyl adipate, and n-nonyl adipate), dibutyl sebacate, dioctyl sebacate, diisooctyl sebacate, and butyl benzyl sebacate, triethyl citrate, acetyl triethyl citrate, tributyl citrate, acetyl tributyl citrate, and acetyl trioctyl citrate, methyl phthalyl ethyl glycolate, ethyl phthalyl ethyl glycolate, and butyl phthalyl ethyl glycolate, tri-n-octyl n-decyl trimellitate, dioctyl isophthalate and dioctyl terephthalate, methyl acetyl, recinoleate and butyl acetyl recinoleate, butane diol, ethylene glycol, propane 1 ,2 diol, propane 1 ,3 diol, polyethylene glycol, glycerol, adipic acid, succinic acid, succinic anhydride, hydroxystearic acid, epoxidized soy bean oil (EPSO), chlorinated paraffins, and chlorinated fatty acid esters.

[0103] A lubricant is a material, when introduced ono the friction surface to reduce the friction force and / or the wear rate.

[0104] In some embodiments, the lubricant includes zinc stearate, calcium stearate, magnesium stearate, stearic acid, oleamide, stearamide, erucamide, oalcium stearate, oil (mineral oil, castor oil, and soybean oil), lauric acid, myristic acid, palmitic acid, stearic acid, and oleic acid; fatty acid soaps such as sodium salts or potassium salts of the above aliphatic carboxylic acids; N-acyl-N-methylglycine salts, N-acyl-N-methyl-beta-alanine salts, N- acylglutamic acid salts, polyoxyethylene alkyl ether carboxylic acid salts, acylated peptides, alkylbenzenesulfonic acid salts, alkylnaphthalenesulfonic acid salts, alkyl sulfosuccinate disalts, polyoxyethylene alkylsulfosuccinic acid disalts, alkylsulfoacetic acid salts, (alphaolefinsulfonic acid salts, N-acylmethyltaurine salts, sodium dimethyl 5-sulfoisophthalate,sulfated oil, higher alcohol sulfuric acid ester salts, polyoxyethylene alkyl ether sulfuric acid salts, secondary higher alcohol ethoxysulfates, polyoxyethylene alkyl phenyl ether sulfuric acid salts, monoglysulfate, sulfuric acid ester salts of fatty acid alkylolamides, polyoxyethylene alkyl ether phosphoric acid salts, polyoxyethylene alkyl phenyl ether phosphoric acid salts, alkyl phosphoric acid salts, sodium alkylamine oxide bistridecylsulfosuccinates, sodium dioctylsulfosuccinate, sodium dihexylsulfosuccinate, sodium dicyclohexylsulfosuccinate, sodium diamylsulfosuccinate, sodium diisobutylsulfosuccinate, alkylamine guanidine polyoxyethanol, disodium sulfosuccinate ethoxylated alcohol half esters, disodium sulfosuccinate ethoxylated nonylphenol half esters, disodium isodecylsulfosuccinate, disodium N-octadeeylsulfosuccinamide, tetrasodium N- (1 ,2-dicarboxyethyl)-N-octadecylsulfosuccinamide, disodium mono- or didodecyldiphenyl oxide disulfonates, sodium diisopropylnaphthalenesulfonate, and sodium naphthalenesulfonate.

[0105] A UV resistant additive functions to improve the resistance of polymers to the damaging effects of UV radiation. UV resistant additives aim to protect the polymers from discolouration, and loss of mechanical properties caused by prolonged exposure to sunlight. By incorporating a UV resistant additive into the polymer during compounding, the compounded material can gain improved durability and longevity in outdoor applications. UV resistant additives typically work by absorbing or reflecting UV radiation, thereby preventing UV radiation from reaching the polymers.

[0106] In some embodiments, the UV resistant additives include UV-P, UV-326, UV-327, UV- 328, UV 531 , UV-329 UV-3896, UV-328, UV-119, SONGSORB 1000 and SONGSORB 2340, HALS 770, and Appolo 1164 etc.

[0107] Heat stabilizers are typically used in polymer compounding to protect the polymer from degradation due to exposure to heat, light, and other environmental factors. Some polymers can be sensitive to high temperatures, which can lead to chain scission, cross-linking, discolouration, and other detrimental effects that reduce the material's performance and lifespan. Heat stabilizers function to slow down these degradation processes, thereby enhancing the polymer's thermal stability and overall durability.

[0108] In some embodiments, the heat stabilizers include cyclohexylphosphonic acid, 1- cyclohexenylphosphonic acid, 1-hydroxycyclohexenylphosphonic acid, 1-hexanephosphonic acid, 1-hydroxyethylidene 1 ,1-diphosphonic acid, or dicyclohexylphosponic acid, 2,4,4- (trimethylpentyl)cyclohexylphosphonic acid, phosphoric acid, trimethylphosphate ortriethylphosphate; 2,6-di-t-butyl cresol, octadecyl-3- (4-hydroxy-3,5-di-t-butylphenyl) propionate, tetrabis [methylene-3- (3,5-di 4-butyl-4-hydroxyphenyl) propionate] methane, 1 ,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxy benzyl) benzene , 3,5-di -t- butyl-4- hydroxybenzyl phosphate diethyl ester, 4,4'-butylidene-bis (3-methyl -6-t- butylphenol), 4, 4 ' Hindered phen secondary primary oxidation such as thiobis P-methyl — 6-t-butylphenol) or Bis [3,3-bis- (4'-hydroxy-3'-tert-butyl-phenyl) butanoic acid] glycol .ester Inhibitors; Amines such as phenyl-a-naphthylamine, phenyl-p-naphthylamine, N, N'-diphenyl-P- phenylenediamine or N, N'-di-p-naphthyl-P-phenylenediamine Secondary antioxidant system; Dilauryl disulfide, dilaurylthiopropionate, distearylthiopropionate, mercaptobenzothiazole, B225 from BASF, CARSTAB DLTDP from Struktol, Naugard DLTDP etc.The thermal stabilizer can also comprise oxides, hydroxides, or carboxylic acid salts of a metals from Groups I to V of the Periodic Table. For example, calcium stearate, barium stearate, magnesium stearate, barium stearate, zinc stearate, and zinc oxide.

[0109] A grafting agent functions to modify surfaces of a nano-filler or a micro-filler.

[0110] The inventors have observed that the surface properties of nano-fillers and micro-fillers may impact their industrial applications. Depending on a specific industrial application, surfaces of a nano-filler or a micro-filler might need to be modified, e.g. to improve dispersion, stability, and compatibility with diverse matrices. For example, some industrial application may need increased solubility, biocompatibility, and resistance to agglomeration. The inventors have found that surface modification can facilitate the incorporation of nanoparticles into polymers, composites, coatings, and biomedical materials, enhancing mechanical, electrical, and thermal properties. In addition, the inventors have found that functionalizing nanoparticle surfaces can enable the introduction of specific chemical groups, enabling targeted applications such as drug delivery, catalysis, and sensing.

[0111] The inventors have tested surface modification of nano-fillers and micro-fillers using different chemical processes. For example, the inventors tested functional groups, including silane coupling agents, to verify the formation of covalent bonds between the nano-fillers or micro-fillers and grafted polymer. The inventors found that the formed covalent linkage provides a robust interface, thereby improving dispersion and adhesion within the polymer matrix.

[0112] The inventors also tested amphiphilic molecules, including surfactants or co-polymers (PEG-POL, PEG-PHA, PEG-PBS, PEG-PBSA, and PEG-PBAT). The inventors used a surfactant to impart steric stabilization and prevent nanoparticle agglomeration.

[0113] Overall, the inventors found that the chemical interactions between the modified nanofillers or micro-fillers and the polymer matrix can change the mechanical, thermal, and rheological properties of the composite. Without being bound by theory, the inventors believe that the interactions between the modified nano-fillers or micro-fillers and the polymer matrix include hydrogen bonding, van der Waals forces, and electrostatic attractions. The inventors believe that the tailored chemistry of the nano-filler or micro-filler-polymer interface can enhance material homogeneity and influence the overall performance and applicationspecific characteristics of the resulting composite.

[0114] Example grafting agents include: cetyltrimethylammonium bromide (CTAB), hexadecylpyridinium chloride (HPC), sodium dodecyl sulfate (SDS), sodium oleate, Triton X- 100, polysorbate 80 (Tween 80), dodecyldimethylamine oxide (DDAO), cocamidopropyl betaine, aminopropyltriethoxysilane (APTES), methacryloxypropyltrimethoxysilane (MPS), mercaptosilanes, epoxysilanes, citric acid, acrylic acid, oleic acid, organic acid, stearic acid, tetraalkoxy titanates, aluminum alkoxides, zirconium alkoxides, hexamethylene diisocyanate (HDI), maleic anhydride, aryl diazonium salts, glycidyl methacrylate (GMA), mercaptosilanes, and phosphonic acid derivatives.Biodegradable Polymer Composites- Grafted Polymer and Nanofillers

[0115] As used herein, the term "nano-filler" refers to a filler wherein the filler is ground and / or sliced into size particles in the 1-500nm range. The term "micro-filler" refers to a filler wherein the filler is ground and / or sliced into size particles in the 500-2, OOOnm range.

[0116] In one embodiment, the present invention provides a biodegradable polymer composite that has filler particulars in a matrix of a grafted polymer, wherein the filler articles are 500nm or less in size.

[0117] The biodegradable polymer composite may have about 30-99.5% by weight of the grafted polymer and about 0.5 to 50 % by weight of the filler particulars.

[0118] The grafted polymer is made using one or more compatibilizers selected from maleic anhydride, glycidyl methacrylate, pyromellitic anhydride, acrylic acid; polyacrylic acid; methylene diphenyl diisocyanate; poly(glycidyl methacrylate, copolymer(s) of glycidyl methacrylate and copolymers of acrylic acid, and / or about 0.1 to 50 % by weight of PBAT grafted with one or more compatibilizers selected from maleic anhydride, glycidyl methacrylate, pyromellitic anhydride, acrylic acid, polyacrylic acid, methylene diphenyldiisocyanate, poly(glycidyl methacrylate, copolymer(s) of glycidyl methacrylate and / or copolymers of acrylic acid.

[0119] The grafted polymer may be free of functional monomer.

[0120] The grafted polymer may be free of any PLA and any petroleum-derived polymer.

[0121] In some embodiment, the grafted polymer includes is polybutylene adipate terephthalate (PBAT) polymer, a mixture of PBAT, starch and a plasticizer, or a blend of PBAT and thermoplastic starch. In some embodiments, the PBAT component is polybutylene adipate terephthalate (PBAT).

[0122] In some embodiments, the grafted polymer is a mixture of PBAT, starch, and a plasticizer, wherein PBAT is about 50-65% by weight of the composition, the starch is about 15 to 35% by weight of the composition, and the plasticizer is about 10 to 15% by weight of the composition.

[0123] In some embodiments, the grafted polymer is a PBAT-thermoplastic starch blend, wherein PBAT is about 50-65% by weight of the composition, and the thermoplastic starch is about 30 to 40% by weight of the composition.

[0124] In some embodiments, the grafted polymer is a blend of a first polymer and a second polymer made using one or more compatibilizers selected from maleic anhydride, glycidyl methacrylate, pyromellitic anhydride, acrylic acid; polyacrylic acid; methylene diphenyl diisocyanate; poly(glycidyl methacrylate, copolymer(s) of glycidyl methacrylate and copolymers of acrylic acid, and / or about 0.1 to 50 % by weight of PBAT grafted with one or more compatibilizers selected from maleic anhydride, glycidyl methacrylate, pyromellitic anhydride, acrylic acid, polyacrylic acid, methylene diphenyl diisocyanate, poly(glycidyl methacrylate, copolymer(s) of glycidyl methacrylate and / or copolymers of acrylic acid.

[0125] In some embodiments, the composition and / or biocomposite of the present invention comprises one or more compatibilizers selected from maleic anhydride, pyromellitic anhydride, acrylic acid; polyacrylic acid, methylene diphenyl diisocyanate, and copolymers of acrylic acid.

[0126] In some embodiments, the composition and / or biocomposite of the present invention comprises one or more compatibilizers selected from maleic anhydride, glycidyl methacrylate, pyromellitic anhydride and methylene diphenyl diisocyanate.

[0127] In some embodiments, the composition and / or the biocomposite of the present invention further comprises about 20-40% of a plasticizer.

[0128] Non-limiting examples of suitable plasticizers include polyols (such as glycerol), ethylene glycol, polyglycerol, sorbitol, sucrose, fructose, glucose, urea, acetylated monoglycerides alkyl citrates, triethyl citrate (TEC), acetyl triethyl citrate (ATEC), tributyl citrate (TBC), acetyl tributyl citrate (ATBC), trioctyl citrate (TOC), acetyl trioctyl citrate (ATOC), trihexyl citrate (THC), acetyl trihexyl citrate (ATHC), butyryl trihexyl citrate (BTHC), trimethyl citrate (TMC), alkyl sulfonic acid phenyl ester (ASE), lignosulfonates, beeswax, oils, sugars, polyols such as sorbitol and glycerol, low molecular weight polysaccharides, diethylene glycol dibenzoate (DEGDB), 1 ,5-propanediol dibenzoate (1 ,5-PDB), propylene glycol dibenzoate (PGDB), dipropylene glycol dibenzoate (DPGDB), alkyl dibenzoates, succinates, maleates, fumarate, or a combination thereof.

[0129] In some embodiments, the plasticizer is selected from diethylene glycol dibenzoate (DEGDB), 1 ,5-propanediol dibenzoate (1 ,5-PDB), propylene glycol dibenzoate (PGDB), dipropylene glycol dibenzoate (DPGDB), alkyl dibenzoates, succinates, maleates, fumarate, or a combination thereof.

[0130] In some embodiments, the biodegradable polymer composite is manufactured by:• combining a polymer with one or more compatibilizers to form a reaction mixture;• melting the reaction mixture to form the grafted polymer;• modifying surfaces of a nano-filler or a micro-filler using a grafting agent;• mixing the grafted polymer with the surface modified nano-filler or micro-filler to form a mixture; and• extruding the mixture at a processing temperature sufficient to melt at least the polymer.

[0131] In some embodiments, the biodegradable polymer composite is manufactured by:• modifying surfaces of a nano-filler or a micro-filler using a grafting agent;• mixing a compatibilizer, an antioxidant, a heat stabilizer, a processing aid, a lubricant, a chain extender, a pigment, an UV stabilizer, an anti-blocking agent, a polymer, and the surface modified nano-filler or micro-filler to form a reaction mixture;• melting the reaction mixture to form the biodegradable polymer composite; and• extruding the mixture at a processing temperature sufficient to melt at least the polymer.Biodegradable Polymer Composites- PBAT and Hemp Residue

[0132] As used herein, the term "hemp residue" (HR), refers to ground hemp stalk wherein the hemp hurd and / or fibers are ground and / or sliced into micron size particles. The residue can be in the form of powder or dust.

[0133] Some embodiments of the present invention relate to novel compositions for making a biodegradable biocomposite, and the biodegradable biocomposites formed from these compositions.

[0134] The biocomposites exhibit enhanced tensile modulus, tensile strength, and heat deflection while maintaining sufficient toughness of biocomposites, and exhibit overall appealing material properties, and compostability compared to the neat PBAT, making it attractive for a range of single-use consumer goods, such as fast-food utensils, cosmetic containers, and food containers.

[0135] In one embodiment, the present invention provides a composition for use in making a biodegradable biocomposite, which comprises: a) about 30-99.5% by weight of a polybutylene adipate terephthalate (PBAT)-component; and about 0.5 to 50 % by weight hemp residue. The composition also optionally comprises about 0.1 to 50 % by weight one or more compatibilizers selected from maleic anhydride, glycidyl methacrylate, pyromellitic anhydride, acrylic acid; polyacrylic acid; methylene diphenyl diisocyanate; poly(glycidyl methacrylate, copolymer(s) of glycidyl methacrylate and copolymers of acrylic acid, and / or about 0.1 to 50 % by weight of PBAT grafted with one or more compatibilizers selected from maleic anhydride, glycidyl methacrylate, pyromellitic anhydride, acrylic acid, polyacrylic acid, methylene diphenyl diisocyanate, poly(glycidyl methacrylate, copolymer(s) of glycidyl methacrylate and / or copolymers of acrylic acid.

[0136] In another embodiment, the present invention provides a biodegradable biocomposite, which is made from a mixture of about 30-99.5% by weight polybutylene adipate terephthalate (PBAT)-component; and about 0.5 to 50 % by weight hemp residue. The mixture optionally comprises about 0.1 to 50 % by weight one or more compatibilizers selected from one or more maleic anhydride, glycidyl methacrylate, pyromellitic anhydride, acrylic acid; polyacrylic acid, methylene diphenyl diisocyanate, poly(glycidyl methacrylate, copolymer(s) of glycidyl methacrylate and copolymers of acrylic acid, and / or about 0.1 to 50 % by weight of PBAT grafted with one or more compatibilizers selected from maleic anhydride, glycidyl methacrylate, pyromellitic anhydride, acrylic acid, polyacrylic acid, methylene diphenyl diisocyanate; poly(glycidyl methacrylate, copolymer(s) of glycidyl methacrylate and / or copolymers of acrylic acid, wherein the mixture is heated.

[0137] In some embodiment, the PBAT-component of the present invention is polybutylene adipate terephthalate (PBAT) polymer, a mixture of PBAT, starch and a plasticizer, or a blend of PBAT and thermoplastic starch. In some embodiments, the PBAT component is polybutylene adipate terephthalate (PBAT).

[0138] In some embodiments, the PBAT-component is a mixture of PBAT, starch, and a plasticizer, wherein PBAT is about 50-65% by weight of the composition, the starch is about 15 to 35% by weight of the composition, and the plasticizer is about 10 to 15% by weight of the composition.

[0139] In some embodiments, the PBAT-component is a PBAT-thermoplastic starch blend, wherein PBAT is about 50-65% by weight of the composition, and the thermoplastic starch is about 30 to 40% by weight of the composition.

[0140] In some embodiments, the composition and / or biocomposite of the present invention comprises one or more compatibilizers selected from maleic anhydride, pyromellitic anhydride, acrylic acid; polyacrylic acid, methylene diphenyl diisocyanate, and copolymers of acrylic acid.

[0141] In some embodiments, the composition and / or biocomposite of the present invention comprises one or more compatibilizers selected from maleic anhydride, glycidyl methacrylate, pyromellitic anhydride and methylene diphenyl diisocyanate.

[0142] In some embodiments, the composition or biocomposite of the present invention comprises PBAT grafted with one or more of maleic anhydride, glycidyl methacrylate, pyromellitic anhydride and acrylic acid.

[0143] In some embodiments, the composition and / or the biocomposite of the present invention further comprises about 20-40% of a plasticizer.

[0144] Non-limiting examples of suitable plasticizers include polyols (such as glycerol), ethylene glycol, polyglycerol, sorbitol, sucrose, fructose, glucose, urea, acetylated monoglycerides alkyl citrates, triethyl citrate (TEC), acetyl triethyl citrate (ATEC), tributyl citrate (TBC), acetyl tributyl citrate (ATBC), trioctyl citrate (TOC), acetyl trioctyl citrate (ATOC), trihexyl citrate (THC), acetyl trihexyl citrate (ATHC), butyryl trihexyl citrate (BTHC), trimethyl citrate (TMC), alkyl sulfonic acid phenyl ester (ASE), lignosulfonates, beeswax, oils, sugars, polyols such as sorbitol and glycerol, low molecular weight polysaccharides, diethylene glycol dibenzoate (DEGDB), 1 ,5-propanediol dibenzoate (1 ,5-PDB), propylene glycol dibenzoate (PGDB), dipropylene glycol dibenzoate (DPGDB), alkyl dibenzoates, succinates, maleates, fumarate, or a combination thereof.

[0145] In some embodiments, the plasticizer is selected from diethylene glycol dibenzoate (DEGDB), 1 ,5-propanediol dibenzoate (1 ,5-PDB), propylene glycol dibenzoate (PGDB), dipropylene glycol dibenzoate (DPGDB), alkyl dibenzoates, succinates, maleates, fumarate, or a combination thereof.

[0146] The hemp residue of the present invention can be prepared by milling and / or grinding the hemp stalk to obtain micron size particles. In some embodiments, hemp residue comprises ground hemp hurd and bast fibers. In some embodiments, the hemp residue is primarily composed of the hemp core and residual bast fibers. In some embodiments, the hemp residue is composed of hemp hurd. In some embodiments, the residue is in the form of a powder.

[0147] In some embodiments, before milling or grinding, the hemp stalk is washed with about 2-10% solution of sodium hydroxide in water (1 part stalk per 10 parts solution by weight), and then dried.

[0148] In some embodiments, the hemp residue comprises particles having length about 75 to 150 pm, width about 15 to 40 pm, and an aspect ratio of about 3.5 to 5. In some embodiments, the hemp powder has density about 1.0 to 2.0 g / cm3.

[0149] In some embodiments, the hemp residue comprises about 60-75% cellulose, 5-15% hemicellulose and about 10-25% lignin.

[0150] In some embodiments, the hemp residue is pre-treated to remove tetrahydrocannabinol (THC) & cannabidiol (CBD).

[0151] In some embodiments, the composition and / or the biocomposite of the present invention comprises PBAT as the PBAT-component, hemp residue and a compatibilizer or PBAT grafted with one or more compatibilizers.

[0152] In some embodiments, the composition and / or the composite of the present invention comprises 30 to 99% of PBAT, about 5 to about 40% hemp residue, and about 0.1 to 20% PBAT grafted with one or more compatibilizers. In some embodiments, the compatibilizer is maleic anhydride.

[0153] In some embodiments, the composition comprises: about 50 to 70% by weight PBAT; about 25 to 30% by weight starch; about 10 to 15% by weight glycerol; about 0.2 to 0.7% by weight stearic acid; and about 0.2% to about 0.7 by weight hemp residue.

[0154] The starch can be any plant starch (root and / grain starch), such as potato starch, sweet potato starch, corn starch, bracken starch, wheat starch, cassava starch, sago palm starch, rice starch, tapioca starch, soybean starch, arrow root starch, lotus starch, buckwheat starch or any mixture thereof.

[0155] In some embodiments, starch is unprocessed (i.e. in a natural state thereof), wherein the starch has not been modified by chemical or any other means.

[0156] In some embodiments, composition and / or the biocomposite comprises about 1 to 3% by weight of a processing agent, such as glycerol monostearate and / or stearic acid.

[0157] In some embodiments, composition and / or the biocomposite comprise an inorganic filler (such as, talc, clay, wollastonite, montmorillonite, or carbonate bicarbonate, oxide or sulfate of alkali metal or alkali earth metal).

[0158] In some embodiments, the composition further comprises about 0.5-5% a colorant, such as mineral and / or dye. In some embodiments, the composition comprises about 1 % colorant.

[0159] In some embodiments, the present invention provides a method of preparing a biodegradable biocomposite of the present invention. The method comprises, admixing the PBAT-component with hemp residue, and optionally with a compatibilizer or compatibilizer- grafted PBAT described herein, and extruding the admixture at an extrusion temperature sufficient to melt at least the PBAT. In some embodiments, the admixture is extruded via a screw extruder at a screw speed of about 80-120 rpm, at a processing temperature of about 150°-220°C. In some embodiments, the admixture is extruded via a screw extruder with a screw speed of about 380-450 rpm, at a processing temperature of about 130°-200°C.

[0160] In some embodiments, the PBAT-component and hemp powder are dried to remove residual moisture before processing. The drying step can be achieved in a conventional oven at about 60-100°C, or via common industrial methods of drying, for example, using a desiccant wheel dryer or a Munters desiccant wheel (at about 40-60°C overnight).

[0161] In some embodiments, the resulting biocomposite is air-cooled and pelletized.

[0162] In some embodiments, the compatibilizer-grafted PBAT can be prepared by combining PBAT with the one or more compatibilizers to form a reaction mixture, and melt processing the reaction mixture to form the grafted PBAT.

[0163] In some embodiments, PBAT is first mixed with one or more compatibilizers and heated to a temperature sufficient to melt at least one of the compatibilizer, followed by adding a free radical initiator prior to the melt processing.

[0164] In some embodiments, the melt processing is achieved at a temperature of about 150°- 220°C.

[0165] In some embodiments, the melt processing comprises melt extrusion. In some embodiments, the melt extrusion is performed via a screw extruder at a screw speed of about 80-850 rpm (including any range included therein, e.g. 150-750 rpm, 100-600 rpm, 150-300 rpm, 350-650 rpm, 600-700 rpm, and 200-600 rpm, at a feed rate of about 100-750 kg / h (including any range included therein, e.g. 300-750 kg / h, 320-400 kg / h, 400-450 kg / h, 500- 550kg / h, 500-600 kg / h, 600-650 kg / h, and 600-700 kg / h).

[0166] In some embodiments, the produced biocomposite is dried to remove unreacted compatibilizer.

[0167] In some embodiments, the biocomposite of the present invention, which comprises PBAT grafted with one or more compatibilizers, can be prepared by: a) first preparing the grafted PBAT by combining PBAT with one or more compatibilizers to form a reaction mixture, and melt processing the reaction mixture to form the grafted PBAT; and b) then mixing the grafted PBAT prepared in step a) with PBAT-component, hemp residue, and optional plasticizer(s) and / or filler(s), and extruding said mixture at a processing temperature sufficient to melt at least the PBAT.

[0168] In some embodiments, the present invention provides a biocomposite made by the methods described herein.Resin Processing

[0169] The inventors have developed an extrusion compounding process for manufacturing biodegradable polymer composites.

[0170] The inventors note that the compounding process can impact the physical properties of the resulting biodegradable polymer composites. The inventors investigated the process parameters, including temperature profile, screw speed, residence time, and feed rate, and their impact on the physical properties of the resulting biodegradable polymer composites.

[0171] The inventors note that biodegradable polymers are typically sensitive to heat and shear and can be prone to hydrolytic degradation if moisture is present in the molten stage. The inventors observed that elevated temperatures, pressures, and moisture levels can result in molecular-weight loss and decreased mechanical properties. The inventors observed thattorque motion can be deployed to melt and process biodegradable polymers. The intensity of the torque motion can be a rate-limiting factor when processing biodegradable polymers.

[0172] In some embodiments, a biodegradable polymer is processed using an extruder. Before extrusion, the biodegradable polymer is kept in a dry environment to minimize moisture pickup and to a moisture level lower than 250 ppm. For example, biodegradable polymer pellets delivered in containers are kept sealed until the material is ready for drying / processing. Pellets stored in silos are purged with dry air or nitrogen to minimize moisture pick-up. The biodegradable polymers are dried in a desiccant dryer prior to extrusion, to a moisture level lower than 250 ppm.

[0173] Before feeding the biodegradable polymer, the extruder is cleaned and purged to avoid cross-contamination.

[0174] The extruder may be a co-rotating, intermeshing twin-screw extruder (TSE). The inventors have developed a TSE that utilizes modular barrels and screws, allowing specific screw and barrel geometries to be matched to the unit operation performed in the extruder. In some embodiments, the co-rotating, intermeshing TSE includes self-wiping screws, so standard metallurgies for screws and barrels can be used, such as hardened tool steels and powder metallurgies for increased abrasion resistance. All metal parts in the extrusion process that have stagnant flow areas — adapters, screen changers and dies — are made of stainless steel and / or hard-chrome plated for increased corrosion resistance.

[0175] The inventors have considered free volume when designing a TSE and the outside diameter (OD) vs. the inside diameter (ID) of the screw(s). The OD / ID ratio of a screw is defined by dividing OD by ID. The inventors observed that with a smaller screw shaft, an increased free volume may lead to a decrease in attainable torque. The inventors notes that torque is typically limited by the cross-sectional area of the screw shaft, the shaft design, and metallurgy. Deeper screw flights result in more free volume, but with less torque, since a smaller diameter screw shaft is mandated. Shallower flight depths and lower OD / ID ratios result in a higher average shear rate, compared with lower shear rates inherent with deeper flights and a higher OD / ID ratio.

[0176] The inventors tested symmetrical splined screw shafts with a 1.55 OD / ID ratio to determine whether they were able to provide an acceptable balance of torque and volume. The inventors found that symmetrical splined shafts induced both tangential and radial force vectors into the power-transmission train and the resultant force was not optimized, as the radial force was not applied in a beneficial direction. The inventors then tested asymmetricalsplined shafts to isolate the tangential force vector and observed a higher torque transmission with a smaller shaft diameter. The inventors also tested screw shafts with a1 .66 / 1 OD / ID ratio with deeper flight depths, higher free volume, and increased. The inventors concluded that the combination of deeper flights with increased torque can be beneficial for processing of biodegradable compounds.

[0177] The inventors observed that increased melt temperature and residence time can be detrimental to biodegradable polymers processing.

[0178] The inventors tested streamlined screen changers with 80 to 120 mesh screens. The inventors found that in some embodiments, finer filtration can be problematic since the associated high pressures resulted in increased backpressures and higher melt temperatures, which caused a loss of molecular weight and degradation.

[0179] In some embodiments, the extrusion compounding is performed using a twin-screw extruder with 44 L / D. In such embodiments, the extruder is preheated to a processing temperature, which is set based on the melting point of polymers and can range from 170°C to 220°C. The preheated extruder is fed with the polymer pellets (e.g. PBS, PBAT pellets) at a controlled feed rate depending on the extruder capacity. The feed rate has been observed to impact the mixing efficiency and residence time. The screw speed of the extruder is adjusted to achieve a compounding effect which ranges from 100 to less than 600 rpm. The screw speed is observed to impact the shear and mixing capabilities of the extruder. For example, a higher screw speed generates more shear which might degrade the polymer. A temperature profile is established along the length of the extruder barrel. The profile includes several heating zones, each set at a specific temperature. The feed zone has a lower temperature to avoid bridging of the material in feed throat. The temperature profile is optimized to achieve sufficient melting, mixing, and homogenization of the polymer (e.g. PBAT). The residence time of the material within the extruder is controlled by adjusting the screw speed and the length of the extruder barrel. The residence time is observed to impact the degree of material degradation and dispersion of additives.

[0180] In some embodiments, a biodegradable polymer composite is prepared by combining various polymers with antioxidants, slip agents / lubricant, pigments, UV stabilizers, fillers, plasticizers, nucleating agents, heat stabilizer, processing aid, cross linker, chain extender. The polymer mixture is prepared by mixing various polymer pellets of PBAT, PBS, PHA, PCL, PGA, CA, TPS, PBSA, PBST etc. in a customised screw assisted desiccant dryer mixing system at 70-80 Celsius for 1 hour prior to processing. In the meantime powder mixtures ofantioxidants, lubricant, pigments, UV stabilizers, fillers, plasticizers, nucleating agents, heat stabilizer, processing aid, cross linker, and chain extender are prepared with the help of a vacuum assisted double ribbon blender with a external heating unit. The various proportions of powders are mixed at 60 rpm on 60 Celsius for 1 hour. Once the polymer pellet and powder mixture are prepared, they are individually fed into gravimetric discharge system where the flow of polymers are powders are controlled by the weight of the material per hour into the TSE.

[0181] Crosslinkers include ethylene glycol dimethacrylate, neopentyl glycol dimethacrylate, 1 ,3-butanediol dimethacrylate, 1 ,4-butanediol dimethacrylate, 1 ,6-hexanediol dimethacrylate, 2-butenediol dimethacrylate, diethylene glycol dimethacrylate, hydroquinone dimethacrylate, catechol dimethacrylate, resorcinol dimethacrylate, triethylene glycol dimethacrylate, polyethylene glycol dimethacrylate; trimethylolpropane trimethacrylate, pentaerythritol tetramethacrylate, ethylene glycol diacrylate, neopentyl glycol diacrylate, 1 ,3-butanediol diacrylate, 1 ,4-butanediol diacrylate, 1 ,6-hexanediol diacrylate, diethylene glycol diacrylate, hydroquinone diacrylate, catechol diacrylate, resorcinol diacrylate, triethylene glycol diacrylate, polyethylene glycol diacrylate; pentaerythritol tetraacrylate, 2-butenediol diacrylate, tetramethylene diacrylate, Carbodiimide, trimethyol propane triacrylate, pentaerythritol tetraacrylate, N-methylolacrylamide, 1 ,2-ethylene bisacrylamide, 1 ,4-butane bisacrylamide, and mixtures thereof.

[0182] In some embodiments, the reaction mixture is melted at a temperature of about 150°- 220°C.

[0183] In some embodiments, the melting processing comprises melt extrusion. In some embodiments, the melt extrusion is performed via TSE at a screw speed of about 200-600 rpm, at a feed rate of about 300-750 kg / h.

[0184] In some embodiments, the produced biocomposite is dried to remove unwanted moisture.

[0185] In some embodiments, the produced biocomposite strands from TSE are cooled in a air-cooled conveyor. In some embodiments, the produced biocomposite strands are cooled under water bath followed by air cooling system.In some embodiments, the produced biocomposite strands are additionally cooled with the help of blown type and suction type Airknife to remove excess water from the strand surface. In some embodiments, the produced biocomposite stands are pelletized and screened by a vibratory screened classifier.

[0186] The additive and fillers may have a particle size in the 1-500nm range.

[0187] The additive and fillers may have a particle size in the 500-2, OOOnm range.Articles Produced Using Biodegradable Polymer Composites of the Present Invention

[0188] In some embodiments, the biodegradable polymer composites of the present invention provide a sustainable alternative to single-use plastics and are suitable for a wide range of applications, such as in the manufacture of articles, including packaging, construction, transportation, consumer goods.

[0189] Example applications include: food packaging (snack bags, frozen food bags, meat and poultry packaging, fresh produce bags, and bakery packaging), beverage packaging (juice box liners, milk carton liners, pouches, coffee bags, and straws), personal hygiene (disposable gloves), agriculture (silage bags, mulch films, greenhouse films, seed bags, and fertilizer bags), retail, flexible packaging, label films, security films, shipping bags, construction (construction films, insulation wraps, tarpaulins, safety netting, and pipe wrapping), electronics (electrical tapes, capacitor films, transformer insulations, circuit board laminates, and cable wrappings), medical (sterilization wraps and medical device packaging), industrial (industrial wraps, heat shrink films, barrier films, insulation films, protective films, and dry ice films), automotive (paint protection films and interior trim films), and cosmetics (sample kit and secondary packaging).

[0190] In some embodiments, a method for manufacturing an article using a biodegradable polymer composite includes the following steps: processing the biodegradable polymer at a temperature (i) above the crystalline melting point of any polymer contained in the composite and (ii) below the decomposition point of any other ingredients (excluding certain branching agents) contained in the composite. During the heat plasticization stage, the biodegradable polymer composite is shaped and cooled to set a desired form and induce crystallization. Various shapes can be achieved, including but not limited to fibers, filaments, films, sheets, rods, tubes, bottles, and other forms. These shapes can be created using well-known techniques such as extrusion, injection molding, compression molding, blowing or blow molding, calendaring, rotational molding, casting, or thermoforming.

[0191] The biodegradable polymer composites invented by the inventors can be utilized to create a wide range of useful products in industries such as automotive, consumer durables, construction, electrical, medical, and packaging. Some examples include packaging films, agricultural films, mulch films, erosion control materials, hay bale wrap, food wrap, protectiveautomobile and appliance wrap, golf tees, caps and closures, agricultural supports and stakes, paper and board coatings, thermoformed products, housings for electronic items, bags, hygiene articles, coatings for pelleted products, injection molded articles, solution and spun fibers, melt blown fabrics, non-wovens, blow molded containers, and foamed articles.

[0192] In a thermoforming process, films or sheets of thermoplastic may be utilized. The biodegradable polymer composites may be processed into a film or sheet, which is then heated in an oven until it becomes soft and pliable. It is then transferred to a mold and formed into the desired shape. During thermoforming, when the semi-crystalline polymer in the biodegradable polymer composites reaches its softening point, the polymer sheet starts to sag. This window between softening and drooping can be narrow, making it challenging to move the softened sheet to the mold quickly. Adding branches to the polymer enhances its melt strength, allowing the sheet to maintain its structural integrity and be processed more effectively. Here, molecular branching is achieved by mixing / reacting polymer with chain extender. Measuring the sag of a heated polymer sample can provide insight into the processing window for thermoforming.

[0193] In some embodiments, the biodegradable polymer composites as described herein have increased melt strength and processability compared to commercial biodegradable polymer. Such biodegradable polymer composites may be used for film or sheet production and for thermoforming. Molded products produced include disposable utensils, tubs, bowls, lids, cup lids, yogurt cups, containers, bottles, and more. The biodegradable polymer composites can be processed into films of varying thicknesses, ranging from 10-200 microns, or can be stacked to form multilayer films with different thicknesses or compositions.

[0194] Blow molding, a similar process to thermoforming used to create deep-drawn products like bottles, also benefits from the increased elasticity, melt strength, and reduced sag of the biodegradable polymer composites. In some embodiments, the inventors observed that the manufactured blown film is durable (meaning that the blown film can be formed into different articles, including packaging articles that withstand transport and have a useful shelf life), even in challenging environments. In some embodiments, the blown film has heat-sealing characteristics, allowing for secure packaging and sealing applications. It is also printable and can be molded into different shapes, providing versatility for various product applications.

[0195] The biodegradable polymer composites can be provided in pellet form for the production of films, coatings, moldings, or other articles.A Flexible Article - Compostable Multilayer Film

[0196] In some embodiments, the biodegradable polymer composites of the present invention can be used to make a compostable multilayer film.

[0197] For example, a co-extrusion and lamination technique can be used to prepare a multilayer film extrudate. The multilayer film extrudate may be cooled over a large moving polished metal roller which can be maintained at a temperature in the range of 5 °C to 40 °C depending upon the ambient temperature conditions.

[0198] The multilayer film may be a two-layer or three-layer biodegradable and compostable film. In some other embodiments, the multilayer film is a five-layer biodegradable and compostable film.

[0199] The thickness of the multilayer film may be in the range of 12 m to 150 pm.

[0200] In some embodiments, the biodegradable polymer composites contain an antiblocking agent. An anti-blocking agent functions to reduce the adhesion of the polymers during production of films and sheets. In addition, the anti-blocking agent also helps in the processing of polymer and reducing melt pressure. Examples of anti-blocking agents include talc, silica, and polysiloxanes.

[0201] In some embodiments, the biodegradable polymer composites contain an antistatic agent. An anti-static agent functions to reduce the development of static charge on the film or sheet surface during an extrusion processing. Examples of anti-static agents include ethoxylated fatty amines, ethelene-bis stearamides, quartenary ammonium compounds, PEGs, zinc stearate, and aluminum trihydrate.

[0202] In some embodiments, one layer of the multilayer film extrudate comprises a slip additive, UV additive, anti-oxidant, pigment to resist weathering, water penetration, or discolouration.

[0203] In some embodiments, an addictive, such as a slip additive, UV additive, anti-oxidant, pigment to resist weathering, water penetration, or discolouration, is contained within or between layers of the multilayer film extrudate.

[0204] In some embodiments, the multilayer film extrudate can be used in farming to replace long vinyl sheets to help seeds grow. To help seeds grow or to promote health of a plant, a biostimulant is contained within or between layers of the multilayer film extrudate. To control release of the biostimulant, the multilayer film extrudate includes two outermost layers containing an antioxidant sandwiching two inner layers containing a pro-oxidant, wherein the biostimulant is contained within or between the two inner layers. A biostimulant functions tostimulate the microbial population present in soil or compost to accelerate the biodegradation rate and may be yeast extract, polysaccharides, carrageenan, guar Gum, heteropolysaccharide, oligosaccharides, sodium lactate, lactic acid, silk fibroin, chitin, Seaweed, chitosan, kaolin, calcium carbonate, or salicylic acid.

[0205] In some embodiments, the multilayer film extrudate may include antimicrobial agent, for example in the outermost layer. Antimicrobial agents include metallic nanoparticles (Ag, Ou, S), oxide nanoparticles (ZnO, TiO2, CuO), clay nanoparticles (bentonite, cloisite, montmorilonitrile), benzalkonium chloride, triclosan, chitosan, tea tree oil, thyme oil, oregano oil, polyhexamethylene biguanide (PHMB), nisin, polyhexamethylene guanidine, triton X-100, grapefruit seed extract, benzalkonium chloride, cinnamaldehyde, and carvacrol.

[0206] A metallized layer may be laminated over an outermost surface layer of the multilayer film. The metallized layer may include chemical vapour deposition of aluminum and may be of thickness in the range of 15 pm to 100 pm.

[0207] A paper-layer may be laminated over an outermost surface layer of the multilayer film. The thickness of the paper layer may be in the range of 10 gsm to 100 gsm.

[0208] In some embodiments, a multi-layer biodegradable film is provided. The film includes (i) a first layer comprising about 30 to 99.5% by weight of a first polymer selected from a group consisting of polybutylene adipate terephthalate (PBAT), polybutylene succinate (PBS), polyhydroxyalkanoates (PHA), and polycaprolactone (PCL) grafted with a first compatibilizer selected from a group consisting of maleic anhydride, glycidyl methacrylate, pyromellitic anhydride, acrylic acid, polyacrylic acid, methylene diphenyl diisocyanate, poly (g lycidy I methacrylate, copolymer(s) of glycidyl methacrylate and / or copolymers of acrylic acid and about 0.5 to 50 % by weight a first nano-filler or a first micro-filler and (ii) a second layer adjacent to the first layer, the second layer comprising about 30 to 99.5% by weight of a second polymer selected from a group consisting of polybutylene adipate terephthalate (PBAT), polybutylene succinate (PBS), polyhydroxyalkanoates (PHA), and polycaprolactone (PCL) grafted with a second compatibilizer selected from a group consisting of maleic anhydride, glycidyl methacrylate, pyromellitic anhydride, acrylic acid, polyacrylic acid, methylene diphenyl diisocyanate, poly(glycidyl methacrylate, copolymer(s) of glycidyl methacrylate and / or copolymers of acrylic acid and about 0.5 to 50 % by weight a second nano-filler or a second micro-filler.

[0209] The first polymer may be the same as the second polymer.

[0210] The first compatibilizer may be the same as the second compatibilizer.A Flexible Article - Resilient to Temperature

[0211] In some embodiments, the biocomposites have a glass transition temperature of about -5°C to about -50°C. At the glass transition temperature, the amorphous regions experience transition from rigid state to more flexible state making the temperature at the border of the solid state to rubbery state. Without being bound by theory, the inventors believe that at this temperature the free volume (gap between the molecular chains) increases by 2.5 time. Glass transition temperature is represented by Tg and is a property of the amorphous materials or the amorphous portion of a semicrystalline materials. When the ambient temperature is below Tg, the molecular chains of amorphous materials are frozen in place and behave like solid glass. Plastic materials with flexible backbone show lower Tg, whereas plastic materials whose molecular structure is stiff, rigid, and inflexible show a higher Tg. Glass transition temperature helps determine various flexible and rigid applications for a material.

[0212] A phase change material may be PBAT, PBS, PCL, PHA, PBSA and / or its blends.Composability and Sustainability of the Biodegradable Polymer Composites

[0213] In some embodiments, the biodegradable polymer composites of the present invention are home compostable. Such biodegradable polymer composites have undergone testing conducted by TUV™ Austria and have been shown to completely biodegrade within 12 weeks in home compost conditions. A material is considered home compostable if it meets the criteria of being biodegradable under home compost conditions (ambient temperature of 25±5° C.) and decomposes to over 90% by weight into CO2 and water within 360 days, adhering to the Australian Standard AS 5810-2010 for "Biodegradable plastics suitable for home composting." Decomposition into CO2 is evaluated through aerobic degradation per ISO 14855-1 (2012) under controlled composting conditions, specifically at ambient temperature (25±5° C.) to simulate home composting instead of the conventional 58° C. used for industrial composting facilities. A material is considered biodegradable at home compost conditions if, after aerobic composting for a maximum of 180 days in a sieve fraction >2 mm at ambient temperature (25±5° C.), at most 10% of the original dry weight remains. Biodegradability is tested according to ISO 20200 at 25±5° C. to simulate home compost conditions. The rate of biological degradation is determined by quantitatively analyzing the produced carbon dioxide. Biodegradability is defined as the ability of organic substances to be broken down by microorganisms in the presence of oxygen (aerobic) into carbon dioxide,water, biomass, and mineral salts or other present elements (mineralization). Composting refers to the aerobic degradation of organic matter to produce compost. Home compost is the product of privately generated organic waste, subjected to composting, and applied to private property soils without commercial transactions. See Example 7.

[0214] Home compostable polymers are those that undergo degradation through natural processes, primarily microbial activity, within a home composting environment. This degradation leads to the breakdown of the polymer into simpler compounds, such as water, carbon dioxide, and organic matter. The timeframe for home compostable polymers to completely biodegrade varies depending on the specific polymer composition and the composting conditions. It can range from a few months to several years. Some home compostable polymers are designed to biodegrade within a shorter period, ensuring they break down effectively in home composting systems. Home compostable polymers are considered more environmentally friendly compared to traditional plastics. They reduce the accumulation of non-biodegradable waste and minimize the potential for plastic pollution. When properly composted, they can contribute to nutrient-rich compost, which can be used to enrich soil and support plant growth. Several standards and certifications exist to validate the compostability of polymers. The most recognized certification for home compostable materials is the OK COMPOST HOME™ certification, provided by organizations such as TUV™ Austria and Vingotte. This certification ensures that the polymer meets specific criteria for compostability in home composting systems.

[0215] In some embodiments, the film made from the biodegradable polymer composites of the present invention is home compostable. See Example 7.

[0216] The urgent need for sustainable solutions to address the global environmental crisis has become increasingly apparent in recent years. As a result, industries are exploring alternative materials to reduce their ecological footprint. One such material is compostable plastics. Compostable plastics offer the potential for reducing waste and promoting a circular economy. Compostable plastics are biodegradable plastics that can break down into natural elements, such as water, carbon dioxide, and biomass, under specific conditions. These materials are derived from renewable sources like corn starch, sugars, vegetable oils, cellulose etc. Compostable plastics possess key characteristics, including biodegradability. Compostable plastics can be broken down by microorganisms into non-toxic components, Environmental Impact: They have a lower carbon footprint compared to traditional plastics, reducing greenhouse gas emissions and energy consumption during production.

[0217] Compostable plastics offer several notable advantages in the pursuit of sustainability including waste reduction (wherein compostable plastics contribute to reducing the volume of waste in landfills, minimizing environmental pollution as they biodegrade); nutrient enrichment (wherein compostable plastics break down in industrial or home composting facilities, they release valuable nutrients into the soil, improving its fertility and contributing to a circular economy); and renewable resource use (by fully or partially utilizing renewable materials as feedstock, compostable plastics reduce reliance on fossil fuels and contribute to the conservation of natural resources).

[0218] While compostable plastics hold promises as an eco-friendly alternative, several challenges and considerations should be acknowledged. Such challenges and considerations include: (i) lack of infrastructure (wherein the widespread adoption of compostable plastics requires a well-developed composting infrastructure to ensure proper disposal and processing and insufficient facilities can hinder the full potential of compostable plastics); (ii) consumer education (wherein public awareness and education are essential for effective waste segregation and appropriate use of compostable plastics and confusion between compostable and conventional plastics can result in improper disposal practices); (iii) production and cost (wherein currently, the production of compostable plastics is more expensive compared to conventional plastics; scaling up production and technological advancements are needed to make compostable plastics more economically viable); and (iv) environmental impact assessment (wherein to comprehensively evaluate the sustainability of compostable plastics, a life cycle assessment (LCA) can be conducted. This assessment should consider factors such as raw material sourcing, manufacturing processes, disposal methods, and environmental impacts at each stage. A thorough LCA can identify areas for improvement and guide the development of more sustainable practices in the compostable plastics industry).

[0219] Compostable plastics offer a promising solution to the environmental challenges posed by conventional plastics. Their biodegradability, reduced carbon footprint, and potential for resource conservation make them an attractive option for promoting sustainability. However, overcoming challenges related to infrastructure, consumer education, and cost is crucial to realizing the full potential of compostable plastics. As we strive for a more sustainable future, fostering research, innovation, and collaboration will be key to harnessing the benefits of compostable plastics while minimizing their drawbacks. By incorporating compostableplastics into a holistic approach to waste management, we can take a significant step towards a greener, more sustainable world.Colour Masterbatch

[0220] In some embodiments, the present invention provides a colour masterbatch. The colour masterbatch contains a colorant and an amphiphilic biodegradable polymer matrix as a carrier. The amphiphilic biodegradable polymer matrix is selected from the group consisting of PBAT-PEG, PHA-PEG, PCL-PEG, TPS-PHA, PBSA-PEG, TPS-PBAT, and TPS-PBS, wherein the amphiphilic nature of the polymer matrix enhances compatibility with both polar and non-polar polymers.

[0221] The amphiphilic biodegradable polymer matrix simultaneously contains hydrophobic and hydrophilic components. The amphiphilic nature of the polymer matrix is achieved by incorporating hydrophilic and hydrophobic functional groups during the synthesis of the biodegradable polymer. The inventor observed that the chemical modification allows the colour masterbatch to exhibit chemical and physical interaction with a wide range of polar, non-polar, hydrophilic, and hydrophobic polymers.

[0222] The colour masterbatch may be universally compatible with polar, non-polar, hydrophilic, and hydrophobic polymers, enabling its integration into diverse polymer matrices. The inventor believes that it is the amphiphilic nature of the biodegradable polymer matrix that imparts universal compatibility with various polymer types. Here, the inventor believes that the colour masterbatch can seamlessly blend with both hydrophilic and hydrophobic polymers due to the balanced presence of hydrophilic and hydrophobic segments in the amphiphilic structure.

[0223] The amphiphilic biodegradable polymer matrix may be grafted biodegradable polymers to enhance compatibility and functionality. Grafted biodegradable polymers, e.g. maleic anhydride grafted PBAT, PBS, PHA, and / or PBSA, obtained through chemical reactions that introduce functional groups onto the polymer backbone, are incorporated into the masterbatch. This grafting enhances compatibility with other polymers.

[0224] The colorant or pigment may be anthocyanins, thermochromic pigments, hydrochromic inks, fluorescein, leuco dyes, polydiacetylenes with the ability to change colour in response to variations in pH and temperature.

[0225] The colorant may be bacterial pigments to provide unique and environmentally friendly coloration.

[0226] Bacterial pigments may be violacein, prodigiosin, pyocyanin, indigoidine, aeruginosin, flexirubin, carotenoids, melanin, and / or pyrrolnitrin, which are produced by engineered bacteria. These pigments contribute to the coloration of the material while aligning with sustainable and eco-friendly principles.

[0227] The colorant may be natural pigments and dyes derived from plant sources to provide sustainable coloration. Natural pigments and dyes, extracted from plant sources such as Anthocyanins, Chlorophyll, Beta-Carotene, Curcumin, Beetroot Extract, Spirulina, Caramel, Cherry Red (E162), Saffron, Turmeric, Spinach Powder, are integrated into the masterbatch to offer environmentally friendly and biodegradable colour options.

[0228] In some embodiments, the color-changing ability is achieved by incorporating pH- sensitive and temperature-responsive colorants or pigments into the colour masterbatch. These colorants undergo reversible chemical reactions or conformational changes in response to changes in pH and temperature, resulting in observable colour changes.

[0229] For example, anthocyanins can exhibit different colors depending on the pH of the surrounding environment. In acidic conditions, they appear red, while in alkaline conditions, they can shift towards blue or purple.

[0230] Thermochromic pigments change colour with variations in temperature. For instance, a thermochromic pigment may be colourless at low temperatures and turn into a vibrant colour at higher temperatures.

[0231] Hydrochromic Inks change colour in response to moisture or changes in humidity.

[0232] Fluorescein in its pure form is yellow, but it turns red under acidic conditions and dark green under alkaline conditions.

[0233] Leuco dyes are colorless in one state and change to a colored state when exposed to specific conditions.

[0234] Polydiacetylenes are a class of polymers that undergo a colour change in response to variations in temperature, pH, or other environmental factors.

[0235] The colour masterbatch may include functionalized nanoparticles like silver nanoparticles, single-walled carbon nanotubes, carbon nanofibers, nanohydroxyapatite, nanocellulose, nanolignin, montmorillonite, graphene oxides, silica, kaolin clay, calcium carbonate, bentonite clay, cloisite clay, mica, wollastonite, or halloysite, whose surfaces are modified using cetyltrimethylammonium bromide (CTAB), hexadecylpyridinium chloride (HPC), sodium dodecyl sulfate (SDS), sodium oleate, Triton X-100™, polysorbate 80 (Tween 80™), dodecyldimethylamine oxide (DDAO), cocamidopropyl betaine,aminopropyltriethoxysilane (APTES), methacryloxypropyltrimethoxysilane (MPS), mercaptosilanes, epoxysilanes, citric acid, acrylic acid, oleic acid, organic acid, stearic acid, tetraalkoxy titanates, aluminum alkoxides, zirconium alkoxides, hexamethylene diisocyanate (HDI), maleic anhydride, aryl diazonium salts, glycidyl methacrylate (GMA), mercaptosilanes, phosphonic acid derivatives. These functionalized nanoparticles may enhance dispersion, mechanical properties, and colour stability.

[0236] Functionalized nanoparticles can be synthesized by attaching specific functional groups to the nanoparticle surface. These functional groups can improve the interaction between nanoparticles and the biodegradable polymer matrix, leading to enhanced dispersion, mechanical strength, and colour stability.

[0237] The colour masterbatch may include cross-linking agents such as ethylene glycol dimethacrylate, neopentyl glycol dimethacrylate, 1 ,3-butanediol dimethacrylate, 1 ,4- butanediol dimethacrylate, 1 ,6-hexanediol dimethacrylate, 2-butenediol dimethacrylate, diethylene glycol dimethacrylate, hydroquinone dimethacrylate, catechol dimethacrylate, resorcinol dimethacrylate, triethylene glycol dimethacrylate, polyethylene glycol dimethacrylate; trimethylolpropane trimethacrylate, pentaerythritol tetramethacrylate, ethylene glycol diacrylate, neopentyl glycol diacrylate, 1 ,3-butanediol diacrylate, 1 ,4- butanediol diacrylate, 1 ,6-hexanediol diacrylate, diethylene glycol diacrylate, hydroquinone diacrylate, catechol diacrylate, resorcinol diacrylate, triethylene glycol diacrylate, polyethylene glycol diacrylate; pentaerythritol tetraacrylate, 2-butenediol diacrylate, tetramethylene diacrylate, Carbodiimide, trimethyol propane triacrylate, pentaerythritol tetraacrylate, N-methylolacrylamide, 1 ,2-ethylene bisacrylamide, 1 ,4-butane bisacrylamide, and mixtures thereof to improve mechanical properties, rheological properties, compatibility and reduce moisture intake.

[0238] Cross-linking agents may be introduced during masterbatch formulation. Cross-linking agents can facilitate cross-linking reactions within the polymer matrix, contributing to improved mechanical strength and rheological properties as well as compatibility.

[0239] The colour masterbatch may include an enzyme that facilitates the biodegradation process, contributing to enhanced environmental sustainability.

[0240] The enzyme may be lipases, amylase, proteases, esterase, and / or oxidoreductase. The enzyme may function to accelerate the biodegradation of the polymer matrix. For example, the enzyme may catalyze specific chemical reactions, thereby promoting the breakdown of the polymer into environmentally benign byproducts.

[0241] The colour masterbatch may possess self-healing properties for autonomous repair of minor damages. The self-healing mechanism involves the incorporation of microcapsules containing healing agents like chitosan, alginate, cellulose derivatives, gelatins etc. When damage occurs, the microcapsules rupture, releasing the healing agents, which interact with the polymer matrix to initiate a self-repair process.

[0242] The colour masterbatch may include anti-microbial agents to inhibit microbial growth and enhance the self-life of the material. The anti-microbial agents may be metallic nanoparticles (Ag, Cu, S), oxide nanoparticles (ZnO, TiO2, CuO), clay nanoparticles (bentonite, cloisite, montmorilonitrile), benzalkonium chloride, triclosan, chitosan, tea tree oil, thyme oil, oregano oil, polyhexamethylene biguanide (PHMB), nisin, polyhexamethylene guanidine, Triton X-100™, grapefruit seed extract, benzalkonium chloride, cinnamaldehyde, and carvacrol. These agents exhibit antimicrobial activity, preventing the growth of microorganisms.

[0243] The colour masterbatch may include a UV stabilizer to protect the colour masterbatch from UV-induced degradation. The UV stabilizer may be hindered amine light stabilizers (HALS) or UV-absorbing nanoparticles such as UV-P, UV-326, UV-327, UV-328, UV 531 , UV-329 UV-3896, UV-328, UV-119, SONGSORB 1000 and SONGSORB 2340, HALS 770, and Appolo 1164. The UV stabilizer functions to absorb or neutralize UV radiation, preventing degradation and colour fading caused by exposure to sunlight.Examples

[0244] Specific examples are described below, which are illustrative and not limiting in nature.Example 1 Preparation of Hemp Powder (HP)

[0245] To produce the HP, the bast fiber was removed from the stalk and the remaining woody core (also called hurd) and residual fiber was processed with a milling machine to prepare a fine powder of hemp hurd and residual fiber with micron-sized particles. The resulting HP contained less than 1 % tetrahydrocannabinol (THC).

[0246] The lignin content of the hemp powder (HP) was determined using a procedure adopted by Zhu et al.

[0020] , Briefly, 1 g of the dried HP was treated with ethanol for 4 h at 30 °C to remove pectin and wax, which was found to be around 2-5%. The ethanol washed hemp powder was then subjected to 72% aqueous sulphuric acid solution digestion at 20 °C for 2h with continuous stirring. After the acid digestion, the solution was diluted to 3% total acidcontent with enough distilled water and boiled for 4 h. The digested mass was subsequently cooled down to room temperature and filtered followed by washing with distilled water. The insoluble content, which was the lignin (L in gram), was dried in a conventional oven at 80 "C for 24 h and weighed. The remaining soluble content was considered as the cellulosic content (cellulose and hemicellulose) of the HP.

[0247] The a-cellulose was quantified by separating the cellulose from HP via dissolving lignin and hemicellulose in an aqueous solution of NaOH (2.5 mol L-1) and Na2SO3 (0.4 mol L-1). A predetermined amount of HP was suspended in a basic solution and refluxed for 12 h at 100°C. After dissolving lignin and hemicellulose, the undissolved content was recovered and washed several times with distilled water to get rid of residual chemicals. The recovered solid was bleached to remove the colorants with boiling hydrogen peroxide solution (2.5 mol L-1). The white solid content was recovered and washed thoroughly with cold distilled water, dried at 80°C overnight and weighed.

[0248] The particle size of the hemp powder prepared as described above was found to be around 120 pm in length and 27 pm in width with an aspect ratio of about 4.4, using microscopic imaging shown in FIG. 1A. The density of HP was measured to be 1.27 gm / cm3 using back-calculation after the reactive extrusion process.

[0249] Constituents such as cellulose, hemicellulose and lignin in hemp powder (HP) were measured using the digestion and acid hydrolysis technique and are listed in Table 1.Table 3. Physico-Chemical Characteristics of Hemp Powder.

[0250] The presence of 68-70% of cellulose confirms the abundance of hydroxyl functional group on the surface of HP. The presence of functional groups on HP was confirmed using FTIR and a typical spectrum is shown in Fig. 1 B. The peaks corresponding to carboxylic functional groups (C=0) and C-0 of pectin and wax were present in the HP and observed at around 1744 cm-1 and 1249 cm-1 , respectively. The stretching vibration of hydroxyl groups, symmetric and asymmetric stretching vibration of C-H group of cellulose noted as a broad peak at 3380 cm-1 , 2903 cm-1 , and 2937 cm-1 , respectively. Peaks between 1312 cm-1 to 1465 cm-1 correspond to cellulose and hemicellulose. Contrarily, spectra ranging from 881 cm-1 to 1168 cm-1 correspond to the backbone structure of cellulose and hemicellulose. Overall, these spectra confirm the presence of pectin, wax, lignin, cellulose, and hemicellulose in the HP used in this study.Example 1-1 Preparation of Nano-Fillers

[0251] Different kind of nanofillers were used, both organic and inorganic materials: silver nanoparticles, single-walled carbon nanotubes, carbon nanofibers, nanohydroxyapatite, nanocellulose, nanolignin, montmorillonite, graphene oxides, silica, kaolin clay, calcium carbonate, bentonite clay, cloisite clay, mica, wollastonite, or halloysite.Example 2 Preparation of MA-qrafted PBAT

[0252] An industry-viable melt extrusion technique was employed to produce MA-grafted PBAT (mPBAT). Initially, PBAT pellets were mixed with 5 wt.% maleic anhydride (MA) and kept in a hot air oven at 80 °C for about 30 min to melt the MA and create thin crust coating over PBAT pellets. The mixture was cooled mixed with 1 wt.% dicumyl peroxide (DCP) as a reaction initiator stirred before melt processing. The reactive extrusion was conducted in a twin-screw extruder (Thermo Scientific, Haake Process 11 , USA) equipped with 8 temperature zones with a temperature profile of 130 / 135 / 140 / 150 / 150 / 140 / 135 / 130°C from the die to feed. The screw (440 mm length, 40:1 LJD) speed was kept at 60 rpm (to ensure sufficient reaction time) at a feed rate of around 500 kg / h. The produced mPBAT was then pelletized, weighed, and dried in a vacuum oven under reduced pressure (100 mbar), and temperature of 80 °C for 24 h to remove unreacted MA from the sample.

[0253] The grafted MA on PBAT was quantified by a titration technique as follows: 1 g of mPBAT was dissolved in 50 mL of chloroform followed by the addition of few drops of hydrochloric acid (HCI) to hydrolyze of all anhydride groups present on the mPBAT.

[0254] The hydrolysis of the anhydride groups leads to the formation of carboxylic acid functionality that was detected as acid value as per ASTM D1386 standard. The hydrolyzed solution was titrated with 0.1 M potassium hydroxide (KOH) dissolved in alcohol in the presence of phenolphthalein as an indicator. The percentage of MA was measured using equation (1).%MAGrafted = W(56.1)(100) -F 2W (1)Where, M, V, and W are molarity, endpoint volume (in liters) of KOH solution used and weight of sample used (in chloroform), respectively. The MA Grafting (calculated based on an average of 5 endpoint volumes) in mPBAT are presented in percent.Example 2-1 Preparation of MA-qrafted PBS, PHA, and POL

[0255] The same industry-viable melt extrusion technique that was employed in Example 2 was also used to produce MA-grafted PBS (mPBS), MA-grafted PHA (mPHA), and MA- grafted POL (mPCL).

[0256] PBS pellets, PHA pellets, and POL pellets each were mixed with 5 wt.% maleic anhydride (MA) and kept in a hot air oven at 80 °C for about 30 min to melt the MA and create thin crust coating over the polymer pellets.

[0257] The mixture was cooled mixed with 1 wt.% dicumyl peroxide (DCP) as a reaction initiator stirred before melt processing. The reactive extrusion was conducted in a twin-screw extruder (Thermo Scientific, Haake Process 11 , USA) equipped with 8 temperature zones with a temperature profile of 130 / 135 / 140 / 150 / 150 / 140 / 135 / 130°C from the die to feed. The screw (440 mm length, 40:1 LJD) speed was kept at 60 rpm (to ensure sufficient reaction time) at a feed rate of around 500 kg / h. The produced mPBAT was then pelletized, weighed, and dried in a vacuum oven under reduced pressure (100 mbar), and temperature of 80 °C for 24 h to remove unreacted MA from the sample.

[0258] The grafted MA on the polymer pellets was quantified by a titration technique as follows: 1 g of mPBS, mPHA, or mPCL was dissolved in 50 mL of chloroform followed by the addition of few drops of hydrochloric acid (HOI) to hydrolyze of all anhydride groups present on the polymer pellets.

[0259] The hydrolysis of the anhydride groups leads to the formation of carboxylic acid functionality that was similarly detected as acid value as per ASTM D1386 standard. The hydrolyzed solution was titrated with 0.1 M potassium hydroxide (KOH) dissolved in alcoholin the presence of phenolphthalein as an indicator. The percentage of MA was measured using equation (1).%MAGrafted = W(56.1)(100) -F 2W (1)Where, M, V, and W are molarity, endpoint volume (in liters) of KOH solution used and weight of sample used (in chloroform), respectively. The MA Grafting (calculated based on an average of 5 endpoint volumes) in mPBAT are presented in percent.Example 3 Fabrication of Biocomposites Comprising PBAT, Hemp Residue andOptionally PBAT Grafted with Compatibilizer

[0260] The PBAT and hemp powder (HP) were weighed and dried overnight in a conventional oven at 80 °C to remove residual moisture before processing. The PBAT was then mixed with different content of HP and mPBAT as shown in Table 4 and melt processed via a twin-screw extruder with a screw speed of 100 rpm at a processing temperature of 180°C (all zone). The produced biocomposites were air-cooled and pelletized. The obtained pellets were used to prepare specimens for tensile test, dynamic mechanical analysis (DMA), and rheology measurements using a piston injection molding system ((HAAKETM MiniJet Pro, Thermo Fisher Scientific, USA) at cylinder temperature, mold temperature and pressure of 190 °C, 30 °C, and 700 bar, respectively. Specimens prepared as such were stored in a zip lock bag for further use. Any further addition of HP beyond 40 wt.% over torqued the extruder because of the increased viscosity, and hence it was not pursued in this research.Table 4. Constituent of the Developed Biocomposite Batches.Batch # PBAT (%) HP (%) mPBAT ( / o)Sample code100 0 0 PBAT90 10 0 PBAT-10HP80 20 0 P BAT-20 H P70 30 0 PBAT-30HP60 40 0 P BAT-40 H P80 10 10 PBAT-10HP-M70 20 10 PBAT-20HP-M60 30 10 PBAT-30HP-M50 40 10 PBAT-40HP-M

[0261] The formation of a gel in the developed biocomposites can be a qualitative indicator of the reaction between the anhydrides of the mPBAT and the — OH moieties of the HP. Thus, the gel content was quantified via Soxhlet extraction through the continuous washing of about 0.5 g of each sample in chloroform at 80 °C. The samples were then wrapped in a filter paper and placed in the extraction chamber. Chloroform was used as the extraction solvent in the Soxhlet setup. The extraction chamber was manually emptied and the process was repeated for a total of 16-20 cycles. This ensured that any PBAT and unreacted mPBAT be fully removed from the sample whilst restricting gel and HP from escape. Filter papers were weighed before and after the extraction and gel content values were calculated as percent values of the initial weight. The Soxhlet extraction did not remove the existing unreacted hemp powder from the samples (as there was no colouration of the solvent). The percentage gel content was calculated using the following equation (2). 100 (2)Where Wi, Wf and C are initial sample weight, sample weight after Soxhlet extraction and HP content of the sample.

[0262] Fourier transform infrared spectroscopy (FTIR) scans were collected using a Nicollet 6700 from Thermo Scientific. 50 mg of each sample was dissolved into 10 mL of chloroform. Once dissolved, a small amount (less than 1 mL) of the solution was dripped onto neat KBr salt pellets. FTIR analysis was then conducted with 64 scans in a nitrogen (N2) background.

[0263] Tensile properties of the samples were measured using a Universal Tensile Machine AGS-X series from Shimadzu, Japan by employing a 500 N load cell at crosshead speed of 5 mm / min with a gauge length of 25 mm. At least five specimens were tested for tensile properties and their average measurements and standard deviations were reported. Specimens were injection molded in dumbbell shape as per ASTM D638 type V with average dimensions of 50 mm (gauge length) x 3.3 mm (thickness) x 3.2 mm (width).

[0264] Thermo-mechanical data were recorded using a DMA machine (Q800, TA Instruments, USA). For this, samples were tested in strain mode using dual-cantilever orientation at 1 Hz frequency within the temperature range -80 °C to 90 °C at a heating rate of 3 °C / min. Rectangular samples (50 mm (length, L) x 11.9 mm (width, VV) x 3 mm (thickness, T)) were injection molded as per ASTM D648-07 for the DMA test. The heat deflection temperature (HDT) of the specimens were also evaluated using DMA. The force (F), strain (e) and deflection (D) required for the measurement was calculated as per the equation given elsewhere

[0021] as follows.Where, a taken as 0.455 MPa stress on the specimen.

[0265] Scanning electron microscopy (SEM). The fractured surface morphologies of the developed biocomposites were examined using a Zeiss Leo 1530 field emission scanning electron microscope (FE-SEM). The prepared fractured samples were lightly coated with gold nanoparticles to obtain high-resolution images.

[0266] Differential scanning calorimeter (DSC). The thermal behavior of PBAT and its biocomposites were investigated using a differential scanning calorimeter (DSC) (Q2000 from TA Instruments, USA), with a typical heat-cool-heat program. Approximately 5 mg of each sample were first cooled to -80 CO, then the samples were heated from -80 °C to 160 °C with a heating rate of 10 °C / min. The samples were then cooled back to -80 °C, and lastly heated again to 160 °C at the same heating rate. The glass transition temperature (Tg), melting temperature (Tm), and enthalpy of fusion (AHm) of the cooling and second heating curves of the DSC thermogram was used to investigate the change of thermal behavior of the PBAT after the incorporation of different HP loading levels. The degree of crystallinity (c) of the PBAT and its biocomposites was calculated from the ratio of area under the second melting peak of the DSC thermogram to the enthalpy of melting for 100% crystalline PBAT as shown in Equation (6) below.Xc= - - - x 100% (6) iWmioo(l Wf)Where AHmis the enthalpy of melting for the PBAT samples, AHmis the enthalpy of melting for 100% crystalline PBAT (i.e. 114 J / g

[0022] ) and wf is the weight fraction of the hemp powder loadings.

[0267] Thermogravimetric analysis (TGA). All extruded samples were pelletized into about 2 mm pieces before characterizing it with a TGA (2 Star System, Mettler Toledo, Switzerland). The TGA scan was conducted from 30 °C to 700 "C at a heating rate of 10 °C / minute in nitrogen (N2) environment. The collected data was analyzed for the temperature peak and onset values.

[0268] Rheology. The melt rheology properties of the neat PBAT and its biocomposites with and without mPBAT were investigated using a Rheometer (Thermo Scientific, HAAKE MARSUSA). The samples were heated to 180 'C within the linear viscoelastic (LVE) region with a parallel plate setup. A 35 mm diameter plate with a 1 mm gap between the plates was employed for the study. A strain of 1 % was applied and the rheological properties of the PBAT biocomposites within the frequency range of 0.01 to 100 Hz were reported.

[0269] MA Grafting of PBAT. The grafting of MA onto PBAT was confirmed using FTIR analysis as shown in FIG. 2. In the case of PBAT, peaks at 2957 cm-1 , 2887 cm-1 and 1734 cm-1 correspond to the stretching vibration of symmetric and asymmetric C-H group and - 0=0 group, respectively. Other peaks around 1100 cm-1 to 1600 cm-1 in the fingerprint region were attributed to stretching vibration of PBAT backbone C-0-C and phenylene groups of PBAT chains. The appearance of a new peak at 3060 cm-1 and 1954 cm-1 correspond to =C-H stretching vibration in anhydride and asymmetric stretching of 0=0 group developed between anhydride and PBAT chains, respectively. A new shoulder developed at 1687 cm-1 is assigned to carbonyl functional groups of lower molecular weight PBAT generated due to p-scission of chains. Altogether, radical initiated MA grafting is successfully carried out. Furthermore, the extent of maleation based on the titration study was found to be 2.27% ±0.28 using equation (1)

[0023] ,

[0270] Thermal behaviors of PBAT / hemp powder biocomposites. The DSC heating and cooling thermogram of PBAT / HP at different hemp powder content are shown in FIG. 3 (A & B). The data extracted from the DSC thermogram, i.e. glass transition temperature (Tg), melting temperature (Tm), crystallization temperature (Tc), and degree of crystallinity (Xc) are presented in Table 5. There was no significant shift of the Tgof the PBAT (less than 1 °C) after the incorporation of hemp powder from 10 to 40 wt%. However, the Tgof the PBAT with mPBAT was shifted to a higher temperature in the mPBAT / HP biocomposites. This indicated the enhanced interactions between PBAT and HP as a result of the coupling effects of MA grafting. The PBAT polymer chain motion was restricted from the strong interphase adhesions with HP due to presence of mPBAT and hence increases the Tg.

[0271] Tmof the PBAT has shifted to a higher temperature after the incorporation of hemp powder (approximately 1-3 °C increased), wherein the 10 wt% hemp-filled PBAT biocomposite showed the highest increment on the Tm. A similar trend was observed for the PBAT-HP / mPBAT biocomposites, where at 10 wt% of the hemp powder showed the highest increment in the Tm. In comparison to the hemp / PBAT with and without the presence of mPBAT in all range of hemp powder loadings, the Tmof the PBAT-HP biocomposites hasreduced with the presence of mPBAT coupling agent. This confirmed the effective compatibilization between the HP and PBAT.

[0272] The melting enthalpy and cooling enthalpy of the PBAT reduces with the increase in the loading of the hemp powder, which indicated that the crystal formation and melt crystallization of the PBAT is hindered by the presence of hemp powder. In addition, the reduction of the PBAT contents with the addition of hemp powder and MA could also be the reasons for the reduced energy required to melt the crystals and reduces the Tm of the biocomposites. The calculated degree of crystallinity, Xc is decreased upon the addition of HP in PBAT. At 40 wt% of HP, the Xc of the PBAT reduced from 3.77% to 2.70% (see Table 5).Table 5. Thermal Properties of PBAT and Its Biocomposites at Different Contents of Hemp Powder with and without MA Coupling Agents.Samples Glass Melting Enthal Crystalliz Enthalp Degree of transition temper py of ation y of Crystallinit temperat ature, fusion, temperat fusion, y, X„ (%)PBAT -34.47 121.90 4.30 87.55 8.90 3.77PBAT-10HP -34.77 124.95 3.35 86.98 7.90 3.27PBAT-20HP -34.83 122.53 3.11 88.73 7.02 3.41PBAT-30HP -35.04 123.14 2.61 89.66 5.77 3.27PBAT-40HP -33.89 123.01 1.85 90.95 4.75 2.70PBAT-10HP- -33.25 123.21 2.93 86.48 8.01 2.86PBAT-20HP- -33.34 119.87 2.75 86.43 6.79 3.02PBAT-30HP- -33.18 120.73 2.51 86.50 5.99 3.15PBAT-40HP- -32.57 121.14 1.81 88.67 4.04 2.65

[0273] As depicted in FIG. 3B, the TO of the PBAT was not significantly affected with the addition of HP up to 30 wt% (only -1 °C differences). The T, shifted to a higher temperature when the HP content reached 40 wt%. The intensity of the Te has reduced and broadened as the hemp powder loading increased. This corresponds to the variations in PBAT's crystallite size when HP was incorporated. The crystallization process of the 40 wt% HP-filled PBAT occurred at -91 °C as compared to 87 °C for the neat PBAT. This indicates that the presence of HP could induce the growth of heterogeneous nucleation and crystallization of the PBAT.

[0274] Overall, the Xc of the HP / PBAT with the addition of MA coupling agent displayed reduction as compared to those without mPBAT. The coupling effect and effective interfacial adhesion between the matrix and hemp powder with the addition of the mPBAT coupling agent caused a higher degree of interruption to the crystallization process and hence the overall degree of crystallinity

[0024] , Therefore, the nucleation rate and X, of the PBAT were reduced with the addition of mPBAT as the interphases of the composites improved.

[0275] FIGS. 4A and 4B depict the results of TGA study of the biocompsites. The degradation onset (Ton) for HP was found to be 281 °C which was far lower than Ton of PBAT (-372 °C). In the case of the biocomposites, HP's degradation temperature has shifted to higher temperatures due to encapsulation of the HP with the PBAT chains which reduces the generation and escape of HP degradation products, such as gases. This encapsulation appeared more prominent in the case of the biocomposites with mPBAT. At least 10 °C upshift in Ton was observed with the incorporation of mPBAT as opposed to the neat PBAT as a matrix of the biocomposites. In the case of the biocomposites with mPBAT, the lowest Ton witnessed was 331 0C , which was high for biocomposites. The observed char formation at the end of the degradation of the biocomposites was also consistent with the loading levels of the HP.

[0276] Mechanical and thermo-mechanical characteristic of biocomposite. FIGS. 5A-5D depict the results of tensile testing of the exemplary biocompsites. The tensile strength at yield (TS) and tensile modulus (TM) increased gradually from 7.9 MPa and 79.5 MPa for the unfilled PBAT to 14.3 MPa and 505 MPa, respectively after the addition of 40% HP. An increase in TS and TM showed the reinforcing effect of the HP. On the contrary, the elongation at break has reduced drastically to 6.8% (PBAT-40HP) from 520% (PBAT) showing the relatively weak interaction between HP and PBAT chains. The TS was improved to 24.4 MPa upon the use of 10% mPBAT showing a remarkable (209%) improvement accompanied by the expected reduction in TM. The ultimate tensile strength (UTS), it increased from 18.7 MPa to 24.4 MPa (31 % improvement) (Table 5). This significant uplift in TS showed the improvement in the interfacial adhesion between the HP and PBAT chains due to the coupling effect of the mPBAT. In comparison to the highly filled PBAT, improvement in the elongation at break was observed with the incorporation of mPBAT. For example, in the case of PBAT with 30% HP, a 165% (FIG. 5A) improvement was observed after the addition of 10% mPBAT which resulted in a 375% improvement in its toughness (FIG. 5B).

[0277] FIGS. 6A-6D depict effect of temperature on specimen load bearing capability was evaluated using DMA analysis against temperature. A significant increase in the storage modulus over the studied temperature range was noted with the incorporation of the HP filler. At 25 °C, unfilled PBAT displayed a storage modulus of 205 MPa, whereas biocomposites with 40 HP (PBAT-40HP) presented 2034 MPa. On the contrary, the incorporation of mPBAT (PBAT-40HP-M) reduced the storage modulus to 1652 MPa, which may be associated with the plasticizing effect of mPBAT which contains small molecular weight chains (FIG. 6A and FIG. 6B). At lower temperatures, similar phenomena were observed. Tan delta which is the indicator of glass transition in the polymeric biocomposites, was found to be between -18 °C to -22 °C (FIG. 6C and FIG. 6D), which is quite dissimilar to DSC data. This variation in glass transition in DSC and DMA is as a result of the different mechanisms used for the analysis.

[0278] For real-life applications, the heat deflection temperature (HDT) is a very important parameter that need to be considered. The data for HDT for the biocomposites are shown in FIG. 5D. The restriction of PBAT chains due to the incorporation of HP led to a noteworthy improvement in HDT. In the case of pristine PBAT, HDT was found to be around 39 °C which increased to 93 °C upon the addition of 40% HP. The addition of mPBAT slightly reduced the HDT to 90 °C resulting from the plasticization effect of low molecular weight PBAT chains.

[0279] Rheological properties of the PBAT biocomposites. FIGS. 7A-7C depicts the melt rheological properties of the developed PBAT biocomposites, i.e. complex viscosity, storage modulus and loss modulus as a function of frequency sweep. It was found that the complex viscosity of the PBAT exhibited Newtonian behavior at low-frequency sweep. While shear thinning behavior gradually took over at high frequency (FIG. 7A). Similarly, for the storage modulus and loss modulus, the PBAT showed no frequency dependence at the low to midfrequency range, which reflects a Newtonian behavior. The reinforcing effect of the HP in the PBAT can be clearly seen in the rheological behavior, as the complex viscosity, storage modulus, and loss modulus of the PBAT are lower than the PBAT-HP biocomposites. The complex viscosity, storage modulus and loss modulus of the PBAT increased with the increase in the loading levels of the HP (FIGS. 7A-C). The complex viscosity of the PBAT at low frequency has gradually changed to shear thinning behavior as the HP contents increased above 20 wt%. The increase in complex vicocity is also applicable for the enhancement in the storage and loss modulus.

[0280] The storage and loss modulus of the neat PBAT showed a typical liquid-like melt deformation response. As the HP increased in the PBAT-HP biocomposites, the storagemodulus and loss modulus has also shifted towards a plateau at low frequency (FIGS. 7B- C).

[0281] The PBAT-10HP with mPBAT showed an enhancement in the complex viscosity, storage and loss modulus as compared to the PBAT-10HP. This indicated greater compatibility and interfacial interactions between components and led to a higher complex viscosity. Besides enhancing the hemp powder-PBAT interactions, it was noted that MA could also cause mild cross linking of the PBAT chains. The hydroxyl and carbonyl groups of the PBAT can be readily connected with the aid of MA during reactive extrusion. As a result, the complex viscosity, storage, and loss modulus of the PBAT were improved when processed with mPBAT. However, the complex viscosity of the PBAT-HP was found to be higher than the PBAT-HP-M at above 20 wt% of HP contents. A similar trend was observed for both storage and loss modulus, indicating that the mPBAT compatibilization effect improved the chain mobility of PBAT and the dispersibility of hemp powder at high HP content. The coupling effect induces flexibility and hence reduces the complex viscosity. The reduction in complex viscosity of the PBAT biocomposites with the aid of mPBAT are encouraging due to the ease of processing at high hemp powder content.

[0282] Mechanism involved in improved interfacial adhesion of HP and PBAT. The incorporation of mPBAT in the biocomposite using a reactive extrusion process resulted in a chemical reaction between mPBAT and hemp powder and form a covalent bond. The formation of a chemical bond encapsulates the HP particles with PBAT chains which can easily be dispersed and interact with PBAT chains upon melt reactive extrusion processing. This improved interfacial interaction significantly affected the tensile strength of the developed biocomposite along with elongation at break and toughness at higher loading (20-40%) of hemp powder.

[0283] The resulting improvement in interfacial adhesion between HP and PBAT is observed using SEM and presented in FIGS. 8A-8D and FIGS. 9A-9D. It can be seen that the hemp powder exhibited corrugated surface structures with the variation of particle size. The fractured surfaces of neat PBAT, PBAT-10HP and PBAT-40HP biocomposites are presented in FIGS. 8B-D, respectively. The PBAT-40HP exhibited poor particles dispersion with overlapping particles as a result of the high loading, while the PBAT-10HP displayed good particle distribution without substantial aggregations. Comparisons of the SEM fractured surfaces of PBAT-HP with and without mPBAT are displayed in FIGS. 9A-D with two different magnifications. It can be noted that the PBAT-HP biocomposites exhibited poor particles-matrix interactions with large interfacial gaps (FIGS. 9A-B). This indicates the surface incompatibility and low interfacial adhesion between the hemp powder and PBAT due to wide disparity in surface polarity. The particles-matrix interface of the biocomposites was found to be significantly enhanced with the incorporation of mPBAT compatibilizer. The hemp powder is completely encapsulated and adhering to the PBAT (FIGS. 9C-D). There are no noticeable gaps present on the particle-matrix interface as can be seen when mPBAT was added in the PBAT-HP. The enhanced interfacial interaction with the addition of mPBAT in the PBAT-HP was also reflected in the tensile strength and elongation at break data discussed in previous sections. The reaction of MA with PBAT and its further reaction with HP leads to gel formation in the polymeric system suggesting successful bridge formation (FIG. 10).

[0284] As discussed above, the incorporation of hemp powder enhances the tensile strength and tensile modulus of PBAT at higher loading. However, higher loading level reduces the toughness and elongation at break of the resulting biocomposites. Reactive extrusion of PBAT with hemp powder and its compatibilization elevate the tensile strength along with the toughness and elongation at break.

[0285] Representative cutlery and flexible films are prepared using PBAT-40HP-M samples as shown in FIG. 11 to showcase the processability, and application of the fabricated biocomposites. Additionally, higher loading of HP may also contribute to the increased rate of biodegradation.Example 4 Fabrication of a Biocomposite Comprising PBAT, Starch, Plasticizer andHemp Residue

[0286] A mixture comprising: a) about 60% by weight polybutylene adipate terephthalate (PBAT); b) about 27% by weight starch; c) about 12% by weight glycerol; c) about 0.5% by weight stearic acid; and d) about 0.5% by weight hemp powder, was extruded using a twin screw extruder OMEGA 20 from STEER World, using the following temperature profile: 25- 130-150-155-165-170-175 °C, at a feeding rate of about 15 Ib / h and a screw speed of 410 RPM.

[0287] Tensile properties of a sample of the product of Example 4 were measured employing a Universal Tensile Machine AGS-X series from Shimadzu with a 500 N load cell at crosshead speed of 5 mm / min and a gauge length of 25 mm.

[0288] Specimens were injection molded in dumbbell shape as per ASTM D638 type V. Results with the average are summarized in Table 6 below:Table 6. Physical Properties of Injection Molded Specimens.*average of 3 replicates

[0289] The biocomposite prepared in Example 4 can be used for film extrusion to form films.

[0290] Using a similar process as described above, the inventors also made biocomposites with the following formulations as set out in Table 7.Table 7. Formulations of Biocomposites.Example 4-1 Fabrication of a Biocomposite Comprising Nano-Fillers and Grafted Polymer

[0291] The inventors made biocomposites with the following formulations as set out in Table 8.Table 8. Formulations of Biocomposites.Example 5 Compounded Resin in Granule Shape

[0292] The densities of the biodegradable polymer composites were determined using the Archimedes' water displacement method, following the ASTM D792 standard. Distilled water was used as the reference liquid in this process to obtain accurate results.

[0293] All mechanical tests were conducted under ambient conditions, adhering to the relevant ASTM standards. These tests aimed to evaluate the strength (including tensile, flexural, impact, and compressive properties) and modulus of the materials. Tensile tests were performed in accordance with ASTM D638 on a universal testing machine, with a cross head speed of 5 mm / min and a gauge length of 50 mm. Flexural properties were investigated using the same testing machine, applying three-point loading conditions at a cross head speed of 2 mm / min and a gauge length of 50 mm, as per ASTM D790. The Izod impact testing was carried out on notched specimens utilizing a pendulum-type impact tester, following ASTM D256, to determine the impact strength of the developed formulation. To ensure reliability and avoid data redundancy, each test was repeated five times. The deviation in the test results was expressed as the error value.

[0294] To study the melting and crystallizing process of the biodegradable polymer composites, a differential scanning calorimeter (DSC-Q 20, TA instruments) was employed in accordance with ASTM D3418. The composite samples were heated from 50 °C to 400 °C at a rate of 10 °C / min and held for 5 min at 400 °C to eliminate any thermal and mechanical history. Subsequently, the samples were cooled to 50 °C at a cooling rate of 10 °C / min undera nitrogen flow rate of 20 mL / min. From the second heating run, composite glass transition temperature (Tg), melting temperature (Tm), and degree of crystallinity (Xc) were determined. The calculation of crystallinity content utilized a fusion enthalpy value of 130 J / g, which is characteristic of 100% crystalline PAEK.

[0295] Thermogravimetric analysis (TGA) was employed to assess the thermal stability of the composites. The experiments were conducted using a Q500 (TA Instruments) apparatus in air, with a ramp rate of 20 °C / min and a gas flow of 20 mL / min. The temperature range for the analysis was from 50 °C to 800 °C.

[0296] The properties of the compounded resin are summarized in Table 9 below. Table 9. Properties of Compounded Resin.Example 5.5 Compounded Resin in Granule Shape

[0297] The compounded resin has a melt flow index of 0.5 to 5g / 10 minutes. Example 6 Film Made from the Compounded Resin of Example 5.5

[0298] The properties of the film made from the compounded resin of Example 5.5 are summarized in Table 10 below.

[0299] The dart impact strength, which assesses the film's resistance to impact forces, was measured in accordance with the ASTM D1709-04 standard.

[0300] The tensile properties, including modulus, strength, and elongation to break, were evaluated using the ASTM D882-02 standard. These properties provide insights into the film's resistance to stretching and breaking under tension. These were measured in two directions: along the flow exiting the die (referred to as "machine direction tear" or "MD Tear") and perpendicular to the polymer flow exiting the die (referred to as "transverse direction tear" or "TD Tear").Table 10. Properties of Film Made from Compounded Resin [S1 to S4],Table 11. Properties of Film Made from Compounded Resin [A1 to A4],Example 7 Compostablility of Film of Example 6 - Laboratory-Scale Test

[0301] The compostability test was conducted in line with ISO 20200 Plastics - Determination of the degree of disintegration of plastic materials under simulated composting conditions in a laboratory-scale test (2015).

[0302] Following deviations were made when compared to ISO 20200 (2015):• The test item was not dried nor soaked in distilled water before start up. • Incubation at 28°C ± 2°C in order to simulate home composting conditions.• A mixture of 2 kg of the < 10 mm fraction of mature compost and VGF per reactor was used instead of 1 kg of synthetic solid waste per reactor.• Once a week the disintegration was visually monitored and moisture conditions was evaluated and adjusted, as needed, instead of the monitoring process as prescribed by ISO 20200 (2015).• The compost was not dried before sieving. The dry matter of the cleaned sample was determined.

[0303] The modifications as prescribed in following standard specifications were taken into account:• AS 5810 Biodegradable plastics - Biodegradable plastics suitable for home composting (2010);• NF T 51-800 Plastics - Specifications for plastics suitable for home composting (2015).

[0304] FIGS. 12A-12E show the composting process of the firm (2.5 cm x 2.5 cm x 49 pm). FIGS. 12A-12E show a visual comparison between the film at Day 0 and after an incubation period of 4 weeks at ambient temperature. At Day 0, the film remained completely intact as shown by FIG. 12A. One week later, small tears started to appear in a few test item pieces but the test material remained largely intact as shown by FIG. 12B. The disintegration proceeded and after 8 weeks of composting tears were observed in all test item pieces and a significant amount of the test material had fallen apart into pieces with varying dimensions as shown by FIG. 12C. During the following weeks, the size and the presence of the test material in the composting reactors significantly decreased. After 11 weeks of composting, only a few small pieces of test material could be retrieved from composting reactor 2 as shown by FIG. 12D. Moreover, the test material in composting reactors 1 and 3 had completely disappeared. The disintegration proceeded and already after 12.0 weeks of composting, which marked the end of the test, all test item pieces had also completely disappeared in composting reactor 2 as shown by FIG. 12E. Because complete disintegration was achieved, the test was stopped after 12.0 weeks of composting instead of the maximum duration of 180 days.

[0305] At the end of the test (after 12.0 weeks) the contents from each reactor were sieved by means of a vibrating sieve over 2 mm in order to recover the not disintegrated residues of the test material in the > 2 mm fraction. No test material remained present in the > 2 mm fraction for the 3 replicates. This corresponded with an average disintegration percentage of100.0% for the film. The degree of disintegration for the three replicates did not differ by more than 20% and as such, the validity requirement of ISO 20200 (2015) is fulfilled.

[0306] The French standard specification NF T51-800 Plastics - Specifications for plastics suitable for home composting (2015) and the Australian standard specification AS 5810 Biodegradable plastics - Biodegradable plastics suitable for home composting (2010) stipulate that a material has demonstrated sufficient disintegration for home composting when after 180 days of composting at least 90% of the test material has reduced to a size < 2 mm in a quantitative test according to ISO 20200 (2015) at ambient temperature (20°C - 30°C).

[0307] As complete disintegration was obtained for the film after 12.0 weeks, it can be concluded that the 90% disintegration criterion as prescribed by NF T51-800 (2015) and AS 5810 (2010) was reached.

[0308] Various features are described herein as being present in “some embodiments”. Such features are not mandatory and may not be present in all embodiments. Embodiments of the invention may include zero, any one or any combination of two or more of such features. All possible combinations of such features are contemplated by this disclosure even where such features are shown in different drawings and / or d2scribed in different sections or paragraphs. This is limited only to the extent that certain ones of such features are incompatible with other ones of such features in the sense that it would be impossible for a person of ordinary skill in the art to construct a practical embodiment that combines such incompatible features. Consequently, the description that “some embodiments” possess feature A and “some embodiments” possess feature B should be interpreted as an express indication that the inventors also contemplate embodiments which combine features A and B (unless the description states otherwise or features A and B are fundamentally incompatible).

[0309] While a number of exemplary aspects and embodiments have been discussed above, those of skill in the art will recognize certain modifications, permutations, additions and subcombinations thereof. It is therefore intended that the following appended claims and claims hereafter introduced are interpreted to include all such modifications, permutations, additions and sub-combinations as are consistent with the broadest interpretation of the specification as a whole.Example 8 Compostablility of Film of Example 6 - Simulated Sea Water

[0310] Without being bound by theory, the inventors believe that the grafted polymer of the present invention would undergo degradation in seawater due to the synergistic effects ofenvironmental factors and microbial activity. The hydrolysis of ester linkages within the polymer structure is a principal mechanism, facilitated by the presence of water in the marine environment. Seawater introduces ions and enzymes, fostering the breakage of chemical bonds and initiating the depolymerization process. Additionally, the composite may be subjected to microbial colonization by marine microorganisms, such as bacteria and fungi, which enzymatically hydrolyze and metabolise the polymer matrix. The hydrolytic degradation is responsible to the breakdown of the biodegradable polymer composite into smaller molecular fragments followed by microbial activity for its metabolization. The extent and rate of degradation are influenced by polymer composition, molecular weight, and the specific environmental conditions prevalent in seawater.

[0311] The compostability test was conducted using simulated seawater or salt water.

[0312] A batch of biodegradable polymer composite pellets was made using the method as set out in Example 5. However, the pellets were different from the compounded resin in granule shape from Example 5. Here, the pellets include an anti-oxidant, namely Irganox 1010. The anti-oxidant was added during compounding process. Without being bound by theory, the inventors believe that the anti-oxidant is present on the surface of and within the pellets. If it is desirable, the inventors contemplated that an anti-oxidant coating could be applied to the compounded resin in granule shape from Example 5. For example, a polymer may be mixed and melted with an anti-oxidant to form an anti-oxidant mixture and the antioxidant mixture is then used to coat a biodegradable polymer composite.

[0313] Some of the biodegradable polymer composite pellets were used to make films, straws, bottles, and tubes.

[0314] The inventors understand that the average salinity of ocean water is about 35 ppt. To create simulated seawater, 35g of salt was mixed and stirred with 1 ,000g of water, until the salt was dissolved.

[0315] Three samples of biodegradable polymer composite pellets, films, straws, bottles, and tubes were submerged in the simulated seawater. The samples were observed to decompose in the simulated seawater over time.

[0316] Without being bound by theory, the inventors believe that the anti-oxidant may have become ineffective under basic conditions, such as in sea water, to cause the grafted polymer to oxidatively degrade.Example 8-1 Compostablility of Film of Example 6 - Sea Water

[0317] A sample of about 1 ,000g of seawater was obtained at the English Bay shoreline in Vancouver from the sea surface with a bucket.

[0318] Three samples of the film of Example 6, each 30 x 30mm, were added to three separate testing bottles.

[0319] About 200ml of sea water was added to each of the testing bottles.

[0320] The film samples were settled into the testing bottles and slowly degrade over time. The degradation process was visualized by change in physical appearance and change in weight of the samples.Example 9 Compostablility of Film of Example 6 - Home Conditions

[0321] The film of Example 6 was tested for compostability and toxicity.

[0322] The testing facility was Normec OWS nv, located at Pantserschipstraat 163, 9000 Gent, BELGIUM.

[0323] A test item is considered to meet the disintegration requirement if not more than 10% of its original dry weight remains after sieving on a 2 mm sieve after 12 weeks of composting. The results of this test can be used for certification in line with:• EN 13432 Requirements for packaging recoverable through composting and biodegradation - Test scheme and evaluation criteria for the final acceptance of packaging (2000);• AS 4736 Biodegradable plastics - Biodegradable plastics suitable for composting and other microbial treatment (2006);• ASTM D6400 Standard Specification for Labeling of Plastics Designed to be Aerobically Composted in Municipal or Industrial Facilities (2023);• ISO 17088 Specifications for compostable plastics (2021);• ISO 18606 Packaging and the environment - Organic recycling (2013).

[0324] The maximum allowed test duration determined by the standards is 12 weeks.

[0325] The standard that was followed was: ISO 16929 Plastics - Determination of the Degree of Disintegration of Plastic Materials under Defined Composting Conditions in a Pilot-Scale Test (2021).

[0326] The composting test was conducted according to ISO 16929 (2021), simulating industrial composting processes, compost was produced for subsequent ecotoxicity tests on the film of Example 6 and resin pellets from Example 5. Test method ISO 16929 (2021) prescribes that a test item shall be added in a concentration of 10% to biowaste in order toprepare compost for subsequent toxicity tests. Therefore, test item (pellets) was cryogenically milled (< 2 mm) and added in a concentration of 10% to biowaste at start of the pilot-scale composting test. The control vessels consisted of pure biowaste. The test was performed in duplicate and lasted 12 weeks. At the end of the composting test, the compost was sieved over a mesh size of 10 mm.

[0327] The operational parameters showed that the test was valid. The temperature profile showed an initial thermophilic phase and a mesophilic continuation, which is representative for industrial composting. The oxygen concentration remained always above 10%. As such, good aerobic conditions were guaranteed during the test. A pH of 6.5 was found for the biowaste at start and after 1.7 weeks the pH was already increased till above 7.7 for all test series and remained above 7.6 during the further test period.

[0328] The quality of the composts to which 10% of the pellet sample was added at start of the composting cycle was equally good compared to the control composts. No volatile fatty acids were found in the test and control composts and they all showed a Rottegrad of V, which demonstrates that the composts were stable and mature. An average pH of 7.9 and 8.5 was measured for the control composts and the test composts, respectively. Similar average salt levels were found in the test composts (2630 pS / cm) when compared to the control composts (2270 pS / cm). At the end of the test low NH4+-N levels (< 20.0 mg NH4+- N / l were found) in all composts, while the NOx- -N content had increased. After 12 weeks an average NOx- -N content of 370 mg NOx- -N / l (control composts) and 58.7 mg NOx- -N / l (test composts) was measured. This indicates that the nitrification process had started and was proceeding well. A somewhat lower total nitrogen (N) and phosphorous (P) content was obtained for the test composts compared to the control composts, while the potassium (K) and the magnesium (Mg) content was somewhat higher in the test composts compared to the control composts. An average density of 0.379 kg / l and 0.411 kg / l was found for the control composts and the test composts, respectively. The C / N ratio varied between 8 and 13. A high average volatile solids degradation was obtained for all series, demonstrating that the composting process has proceeded well.

[0329] In conclusion it can be stated that no negative effect on the composting process and on the (physico-chemical) quality of the produced compost was observed, when adding 10% the pellet sample at start of the composting process.

[0330] Four composting bins with a total volume of 200I each were started: two control bins (CDI-3 / 3-01 and CDI-3 / 3-02) and two test bins (CDI-3 / 3-03 and CDI-3 / 3-04). The control binscontained only biowaste, while the test bins also contained 10% of the pellet sample, cryogenically milled (< 2 mm). The 10% of the pellet sample was necessary to cover subsequent ecotoxicity tests. The exact test set-up is given in the below table. The biowaste consisted of VGF (Vegetable, Garden and Fruit waste) to which 11 % extra structural material was added in order to obtain optimal composting conditions. At start-up, all vessels were filled to the top of the bin.Table 12. Test Set-Up.

[0331] The fresh biowaste was derived from the separately collected organic fraction of municipal solid waste, which was obtained from the biowaste composting plant of Erembodegem, Belgium. The characteristics of VGF and structural material are given in Table 13. Table 14 shows the characteristics of the mixtures in the composting bins.

[0332] The biowaste at start (= VGF + structural material) should have a moisture content and a volatile solids content on total solids (TS) of more than 50% and a pH above 5. From Tables 9-1 and 9-2 it can be seen that these requirements were fulfilled. The biowaste contained a moisture content of 71 .8% and a volatile solids content of 80.4% on TS. At startup a pH of 6.5 was measured. Furthermore, the C / N ratio of the biowaste at start should preferably be between 20 and 30. An optimal C / N ratio of 23 and 30 was obtained for the biowaste and the biowaste with 10% pellet test material.Table 13. Characteristics of VGF and Structural Material.Table 14. Characteristics of the Biowaste and Biowaste with Test Item.

[0333] FIG. 13 shows the temperature evolution during the composting process. According to ISO 16929 (2021) the test is considered valid, for production of compost for subsequent ecotoxicity testing, if following temperature profile is obtained:• Days 2-7: between 60°C and 75°C;• Days 8-28: between 55 (± 5)°C and 70 (± 5)°C;• Days 29-56: between 50 (± 5)°C and 65 (± 5)°C;• Days 57-70: below 55°C;• Days 71-84: below 45°C.

[0334] As can be seen from FIG. 13 these requirements were largely fulfilled. After start-up the temperature increased and after 2 days of composting the temperature in all bins was above 60°C, except for control bin CDI-3 / 3-01 with a minimum temperature of 53.1 °C. Action was taken and after 4 days of composting also the temperature in control bin CDI-3 / 3-01 was above 60°C. Moreover, the temperature in all bins remained below 75°C during the first week of composting, except once after 4 days of composting for test bin CDI-3 / 3-03 with a maximum temperature of 76.8°C and once after 6 days of composting for control bin CDI-3 / 3- 02 with a maximum temperature of 77.0°C. After the first week till 4.0 weeks of composting the temperature remained between 50°C and 75°C. Moreover, after 1 .7 weeks of composting the contents of test bins CDI-3 / 3-03 and CDI-3 / 3-04 were combined into one bin, separated by a net. This was done in order to compensate for the volume reduction, which naturallyoccurs during the composting, and to maintain optimal composting conditions. Six days later, the same was done for control bins CDI-3 / 3-01 and CDI-3 / 3-02. This resulted in a temperature increase. Elevated temperatures during the composting process were also caused by the turning of the contents of the bins, during which air channels and fungal flakes were broken up and moisture, microbiota and substrate were divided evenly. As such optimal composting conditions were re-established, resulting in a higher activity and a temperature increase. After the fourth week until 8.0 weeks of composting a temperature between 45°C and 70°C was obtained. After the eighth week until 10.0 weeks of composting the temperature remained below 55°C, except once for the combined test bin CDI-3 / 3-03&04 after 10.0 weeks of composting with a maximum temperature of 56.4°C. During the last 2 weeks of composting the temperature remained below the 45°C limit, except for the combined test bin CDI-3 / 3- 03&04 with a maximum temperature of 53.6°C. However, each time the temperature criteria were not fulfilled, action was taken to increase or decrease the temperature. Also, during the composting process the bins were placed in different incubation rooms (at ambient temperature, at 40°C and at 45°C) to maintain optimal temperature conditions. The temperature profile showed an initial thermophilic phase and a mesophilic continuation, which is representative for industrial composting and therefore it can be concluded that the temperature conditions were fulfilled. Also, it was noticed that the temperature in the test bins was higher when compared to the control bins between approximately 2.6 and 12 weeks of composting. This indicates that the test material was degrading.

[0335] FIG. 14 shows the CO2 production rate during the composting test (individual measurements at regular points in time), which is representative for biological activity. After start-up a high activity was measured for the control and test bins, after which the CO2 production gradually decreased. At the end of the test a low activity was found for all test series, indicating that the composting process was completed. It was noticed that the 002 production rate was higher in the test bins compared to the control bins from 3 weeks till 12 weeks of composting. This also indicates that the test item was degrading.

[0336] The oxygen concentration of the exhaust air is given in FIG. 15. The oxygen concentration remained always above 10%. Good aerobic conditions were guaranteed during the test.

[0337] FIG. 16 shows the evolution of the pH during the composting cycle, while FIGS. 17 and 18 give the trend in NH4+-N and NOx--N, respectively, for the different bins.

[0338] According to the international standard ISO 16929 (2021) the pH should increase till a value above 7 during composting and not fall below 5. The biowaste at start showed a pH of6.5 and after 1 .7 weeks of composting the pH had already increased till above 7.7 for all test series. During the further test period the pH remained above 7.6. At the end of the test (after 12 weeks) an average pH of 7.9 and 8.5 was measured for the control composts and the test composts, respectively.

[0339] The biowaste at start contained an ammonium content of 167 mg NH4+-N / I. The ammonium content decreased somewhat slower for the control replicates compared to the test replicates. After 7.6 weeks of composting low ammonium levels (< 20.0 mg NH4+-N / I) were obtained for both test replicates. These low ammonium levels maintained till the end of the test. After 12 weeks of composting (= end of the test) also low ammonium levels (< 20.0 mg NH4+-N / I) were obtained for the control replicates.

[0340] After 7.6 weeks of composting an increase of the NOx--N concentration was noticed in both control replicates. At the end of the test an average NOx'-N content of 370 mg NOx_- N / l (control composts) and 58.7 mg NOx'-N / l (test composts) was found.

[0341] At the end of the test low NH4+-N levels were obtained for all replicates, while the NOx—N content had increased. This indicates that the nitrification process had started and was proceeding well.

[0342] At the end of the composting test, the whole contents of the bins were sieved over a mesh size of 10 mm. The > 10 mm fraction was analysed for total solids and volatile solids content. The overall compost quality is determined by the analyses performed on the < 10 mm fraction. The results of all these analyses are given in Table 15.

[0343] To ensure a completion of the normal composting process, the blank biowaste control must have a Rottegrad of IV or V and volatile fatty acids content lower than 500 mg / kg at the end of the test. From Table 15 it can be seen that these requirements were fulfilled for all compost series. The quality of the composts to which 10% of the pellet sample was added at start of the composting cycle was equally good compared to the control composts. No volatile fatty acids were found in the test and control composts and they all showed a Rottegrad of V, which demonstrates that the composts were stable and mature. An average pH of 7.9 and8.5 was measured for the control composts and the test composts, respectively. Similar average salt levels were found in the test composts (2630 pS / cm) when compared to the control composts (2270 pS / cm). At the end of the test low NH4+-N levels (< 20.0 mg NH4+- N / l were found) in all composts, while the NOx- -N content had increased. After 12 weeks anaverage NOx- -N content of 370 mg NOx- -N / l (control composts) and 58.7 mg NOx- -N / l (test composts) was measured. This indicates that the nitrification process had started and was proceeding well. A somewhat lower total nitrogen (N) and phosphorous (P) content was obtained for the test composts compared to the control composts, while the potassium (K) and the magnesium (Mg) content was somewhat higher in the test composts compared to the control composts. An average density of 0.379 kg / l and 0.411 kg / l was found for the control composts and the test composts, respectively. The C / N ratio varied between 8 and 13. A high average volatile solids degradation was obtained for all series, demonstrating that the composting process has proceeded well.Table 15. Chemical Analysis of the Compost Fractions After 12 Weeks of Composting.Table 16. Volatile Solids Degradation for the Different Test Series.

[0344] The disintegration at ambient temperature (28°C) of test item (film) in a thickness of 49 pm was evaluated quantitatively in a laboratory-scale composting test simulating home composting processes. The test procedure was based on ISO 20200 (2015). Test material (film) was added in a 0.5% concentration to a 80 / 20 mixture of < 10 mm mature compost and fresh milled Vegetable, Garden and Fruit waste (VGF) as 2.5 cm x 2.5 cm pieces. The test was performed in triplicate and lasted 12.0 weeks. At the end of the composting test, the compost was sieved and disintegration was evaluated.

[0345] The disintegration of the 2.5 cm x 2.5 cm pieces of film (49 pm) proceeded very swiftly during the test. Already after 12.0 weeks of composting at ambient temperature, all test item pieces had completely disappeared. See FIGS. 12A-12E.

[0346] At the end of the composting test at ambient temperature (after 12.0 weeks), the whole contents of the test reactors were used for sieving, sorting, further isolation and analyses. Disintegration is defined as a size reduction to < 2 mm. No single test item piece was retrieved in the > 2 mm fraction. As can be seen from Table 17, a disintegration percentage of 100.0% was obtained for the film of Example 6 in a thickness of 49 pm.Table 17. Disintegration of Film of Example 6.

[0347] The French standard specification NF T51-800 Plastics - Specifications for plastics suitable for home composting (2015) and the Australian standard specification AS 5810 Biodegradable plastics - Biodegradable plastics suitable for home composting (2010)stipulate that a material has demonstrated sufficient disintegration for home composting when after 180 days of composting at least 90% of the test material has reduced to a size < 2 mm in a quantitative test according to ISO 20200 (2015) at ambient temperature (20°C - 30°C).

[0348] As complete disintegration was already obtained after an incubation period of 12.0 weeks at ambient temperature for test material (film) in a thickness of 49 pm, it can be concluded that the 90% disintegration criterion as prescribed by NF T51-800 (2015) and AS 5810 (2010) was easily reached. Even a higher thickness has the potential to reach this requirement.

[0349] The test item (film) was mixed with a 80 / 20 mixture of < 10 mm mature compost and fresh milled Vegetable, Garden and Fruit waste (VGF) and incubated at 28°C in the dark. Regularly the moisture content was verified and adjusted when needed. The content of the reactors was regularly manually stirred and the test item was visually monitored.

[0350] At the end of the test, the content of the reactors was dried. During the drying process the compost lumps were gently broken. The drying process is terminated when constant mass was reached. The compost from each reactor was sieved by means of a vibrating sieve over 2 mm in order to recover the not disintegrated residues of the test material in the > 2 mm fraction. Disintegration was evaluated very precisely by manual selection. If possible a mass balance was calculated.

[0351] The test was executed in line with ISO 20200 Plastics - Determination of the degree of disintegration of plastic materials under simulated composting conditions in a laboratoryscale test (2015). Following deviations are made when compared to ISO 20200 (2015):• The test item is not dried nor soaked in distilled water before start up.• Incubation at 28°C ± 2°C in order to simulate home composting conditions;• A mixture of 2 kg of the < 10 mm fraction of mature compost and VGF per reactor is used instead of 1 kg of synthetic solid waste per reactor;• Once a week the disintegration will be visually monitored and moisture conditions will be evaluated and adjusted if needed instead of the monitoring process as prescribed by ISO 20200 (2015).• The compost is not dried before sieving. The dry matter of the cleaned sample is determined.

[0352] The modifications as prescribed in following standard specifications were taken into account:• AS 5810 Biodegradable plastics - Biodegradable plastics suitable for home composting (2010);• NF T 51-800 Plastics - Specifications for plastics suitable for home composting (2015).

[0353] The results of the thickness measurements on the film are presented in Table 18. The measured thickness of the test item is taken into account for the disintegration result obtained in this study.Table 18. Thickness of Film of Example 6.

[0354] Three reactors with a dimension of 30 cm x 20 cm x 13 cm (I, w, h) were started for the quantitative evaluation of the disintegration of the film. The reactors contained a 80 / 20 mixture of < 10 mm mature compost and fresh milled Vegetable, Garden and Fruit waste (VGF) and 0.5% 2.5 cm x 2.5 cm pieces of the film.

[0355] The mature compost is a mixture of mature VGF (Vegetable, Garden and Fruit waste) and green compost. The VGF compost is derived from the organic fraction of municipal solid waste (MSW) and is further stabilized and aerated in a pilot-scale composting bin at the laboratory under controlled conditions in order to obtain completely mature compost. The age of the VGF compost is 15 weeks. The green compost is derived from garden waste, prunings, tree roots and stumps and is stabilized in a full-scale composting plant. The composts are mixed in a ratio of 50% VGF compost and 50% green compost.

[0356] The 0.5% test item concentration was used for the determination and quantitative evaluation of the disintegration of the test item. The exact test set-up of the quantitative test is given in Table 19.Table 19. Test Set-Up.

[0357] The characteristics of the inoculum are given in Table 20. The inoculum was characterised by an optimal C / N ratio and moisture content.Table 20. Characteristics of the Inoculum.

[0358] During the composting process the contents of the reactors were mixed weekly and if needed, water was added in order to ensure optimal moisture conditions. The disintegration of the test material (film) was carefully examined during the test.

[0359] With reference to FIGS. 12A-12E, the disintegration of the 2.5 cm x 2.5 cm pieces of the film of Example 6 (49 pm) proceeded very swiftly during the test. FIG. 12A shows a visual comparison between the 2.5 cm x 2.5 cm pieces of the film at start and after an incubation period of 4 weeks at ambient temperature. At the 4-week mark, the test material (film) remained completely intact. One week later, i.e. at week 5, small tears started to appear in a few test item pieces. However, the major part of the test material remained completely intact (FIG. 12B). The disintegration proceeded and after 8 weeks of composting tears were observed in all test item pieces. Moreover, a significant amount of the test material had fallen apart into pieces with varying dimensions (FIG. 12C). During the following weeks the size and the presence of the test material in the composting reactors significantly decreased (12D). After 11 weeks of composting only a few small pieces of test material could be retrieved from composting reactor 2 (12E). Moreover, the test material in composting reactors 1 and 3 had completely disappeared. The disintegration proceeded and already after 12.0 weeks of composting (= end of the test) all test item pieces had also completely disappeared in composting reactor 2. As complete disintegration was obtained for the film, the test was stopped after 12.0 weeks of composting instead of the maximum duration of 180 days.

[0360] At the end of the test (after 12.0 weeks) the contents from each reactor were sieved by means of a vibrating sieve over 2 mm in order to recover the not disintegrated residues of the test material in the > 2 mm fraction. From Table 21 it can be seen that no test material remained present in the > 2 mm fraction for the 3 replicates. This corresponds with an average disintegration percentage of 100.0% for the film (49 pm). The degree of disintegration for the three replicates does not differ by more than 20% and as such the validity requirement of ISO 20200 (2015) is fulfilled.

[0361] The French standard specification NF T51-800 Plastics - Specifications for plastics suitable for home composting (2015) and the Australian standard specification AS 5810 Biodegradable plastics - Biodegradable plastics suitable for home composting (2010) stipulate that a material has demonstrated sufficient disintegration for home composting when after 180 days of composting at least 90% of the test material has reduced to a size < 2 mm in a quantitative test according to ISO 20200 (2015) at ambient temperature (20°C - 30°C).

[0362] As complete disintegration was obtained for test material (film) in a thickness of 49pm after 12.0 weeks, it can be concluded that the 90% disintegration criterion as prescribed by NF T51-800 (2015) and AS 5810 (2010) was easily reached.Table 21 . Disintegration of Tested Film (49 pm) After An Incubation Period of 12.0 Weeks atAmbient Temperature.

[0363] Table 22 shows the results of the chemical analyses at the end of the test. A comparable volatile solids content was measured for the different replicates and normal pH values were obtained. The C / N ratio of the different replicates was 7.Table 22. Chemical Analysis of the Contents of the Reactors at the End of the Test.Example 10 Colour Masterbatch

[0364] A colour masterbatch was made by mixing and melting colorants and plastic granules in a twin-screw extruder, augmented by the addition of small amounts of additives. Both single-stage and two-stage masterbatch production methods were employed. In single-stage production, all raw material components were initially charged and extruded, while two-stage production resulted in "mono-concentrates" that undergo additional mixing in the second step, optionally supplemented with additives, and were then extruded. The uniformity of colour inthe plastic was observed to be contingent on the flow behavior achieved in the melt and how effectively the masterbatch disperses in the matrix.

[0365] The colour masterbatch is biodegradable at home compost conditions (25±5° C) and home compostable.

[0366] Addition studies were conducted to focus on the dispersion of pigments within masterbatches, acknowledging their propensity to agglomerate, making dispersion in polymers challenging. The inventor observed that the colour-imparting ability of pigments in plastic objects is contingent upon their inherent light-dispersing or absorbing capabilities and their particle size.

[0367] The inventor tried to develop a process to produce sizes with acceptable spectral characteristics by breaking down agglomerates during extrusion, a process known as dispersion. The inventor observed that pigments exhibit varying dispersibility characteristics, with titanium dioxide being more easily dispersible, while carbon blacks, organic pigments, and synthetic pigments pose greater dispersion challenges. Poor dispersion can impact the quality and mechanical properties of the final product. Dispersion quality is influenced by screw profile configuration, temperature, rotation speed, and residence time.

[0368] The inventor tried TSE to produce masterbatches. The inventor developed TSE extruded screws, designed with a modular system, to allow the transmission of higher torque, enabling the use of conveying, kneading, and mixing elements. The inventor observed that the versatility of screw combinations in the TSE system facilitates process control, particularly in shear and temperature, ensuring the effective removal of volatile substances in the production of high-concentration masterbatches when the system is appropriately designed.

[0369] The inventor found that in some embodiments, corotating intermeshing twin-screw extruders have superior dispersion capabilities of colour-pigment masterbatches at elevated throughput rates, high levels of pigment loading, extended longevity of screw and barrel components, and straightforward machine operation. The inventor also noted certain challenges inherent in the processing of colour masterbatches include the handling of raw ingredients, effective pigment dispersion, and ensuring cleanliness during colour changes.

[0370] In some embodiments, the inventor positioned feeders above the TSE to mitigate aeration of the feedstock. Air may be entrained together with the powder (not so much with pellets), which needs a place to escape. The absence of filter socks or a central aspiration system connected to the feeding system may impede the feed intake of the feedstock as gas released from the extruder hinders the process. Regarding feedstock aeration, the height ofthe feeder above the extruder can be a factor. Upon entry into a feeder, there exists the potential for powder compaction, resulting in increased bulk density. Depending on the height above the extruder, subsequent aeration of the feedstock during feeding may lead to decreased bulk density, causing issues in feed intake.

[0371] The inventor notes that the process of melting polymer within the twin-screw extruder (TSE) is subject to various influencing factors, encompassing external heating, internal friction, and heat transfer within the polymer melt. The TSE is configured with distinct zones dedicated to the heating and cooling of the internal process, involving the absorption or removal of energy from the system. Internal friction, occurring between polymer pellets or powder particles and the screw elements, induces friction and shear stress within the narrow gaps of kneading blocks, with the screw profile type, throughput rate, and extruder screw speed playing determining roles.

[0372] The design of the kneading and mixing zone is contingent upon the polymer type being processed and may incorporate various kneading elements, such as three-flighted and two- flighted 45° (conveying) kneading elements, two-flighted 90° (neutral) kneading elements, and / or left-handed (retaining) kneading or conveying elements. The combination of these elements imparts the requisite mechanical energy and residence time for efficient polymer melting and homogenization before downstream processing. The left-handed (retaining) elements serve to pressurize the melt within the TSE, necessitating careful design to avoid over-shearing and polymer degradation. It is crucial that the material exiting the melting section be fully molten for proper wet-out of subsequently introduced colour pigment downstream.

[0373] The melting section, integral to achieving high-quality colour pigment dispersions in the TSE, is complemented by the downstream mixing section. Once the colour pigment is effectively introduced and wet-out occurs, the design of the downstream mixing section becomes pivotal for the uniform distribution and dispersion of the colour pigment. Given the entrain of air with pigment powder during entry into a downstream side feeder, where some air is back-vented through an upstream vent, a well-designed downstream mixing section is crucial. Improper design could result in the backward travel of entrained air, hindering material flow. The downstream mixing section serves to wet out the pigment with the melt and convey entrained air downstream, where an atmospheric vent facilitates the release of the entrained air.

[0374] The inventors have developed a method for preparing a home compostable masterbatch with the following steps: (1) blending each component, measured by weight percentage, in a blender to achieve a uniform mixture; (2) introducing the mixture obtained in step (1) into a twin screw extrusion, and through the processes of melt extrusion, cooling, and pelletizing, obtaining the final product. In a preferred embodiment of step (1), the blender's rotating speed is set between 40 and 100 rpm, and the temperature, not exceeding 80°C, ensures uniform mixing for 5 to 30 minutes. In a preferred embodiment of step (2), a twin- screw extruder is employed with a screw having a length-to-diameter ratio ranging from 37:1 to 50:1 , and a rotating speed of 150 to 750 revs / min, including 350 to 650 revs / min, 300 to 600 revs / min, and 650 to 750 revs / min. The screw has an average diameter that range from 18 mm to 120 mm, including any value therebetween, e.g. about 20 mm, 30 mm, 50 mm, 60 mm, 70 mm, 90 mm, 100 mm, and 110 mm. The twin-screw extruder is divided into eight zones, and the temperature is gradually set as follows: the first zone at 90°C ± 5°C, the second zone at 170°C to 180°C, the third zone at 180°C to 200°C, the fourth and fifth zones at 180°C to 210°C, the sixth, seventh and eighth zone at 170- 200°C. Additionally, the cooling and pelletizing in step (2) utilize air-cooled granulation to avoid moisture intake and hydrolytic degradation.

[0375] The components of the masterbatch include a biodegradable polymer resin, commercially available and waste fillers with micron-sized particles, pigments such as pigment dyestuffs or mineral dyes, and additives. Common commercially available biodegradable polymer matrix are used, while the fillers have micron-sized particles. The resulting masterbatch can be coloured in bright red, orange, yellow, green, sky blue, purple, grey, black, white, or other colours. The additives serve to enhance dispersibility, lubrication, compatibility, thermal stability and gloss.

[0376] Eleven colour masterbatch samples were made using the above described method and system and their formulations are set out in Table 23. FIG. 19 is a photo showing the eleven colour masterbatch samples. The samples on average have a diameter of 3-4mm and a length of 3.5-5mm. The samples are biodegradable under home compost conditions (ambient temperature of 25±5°C) and decomposes to over 90% by weight into CO2 and water within 360 days, adhering to the Australian Standard AS 5810-2010.

[0377] The colour masterbatch samples were used to make cutlery and straws. The colour masterbatch samples in a single colour were introduced to a melt-processable biodegradablepolymer, which was prepared using the resin from Example 5. The mixture was processed and compression molded to form cutlery and straws. FIG. 20A-20E show these colourized cutlery and straws.Table 23. Tested Colour Masterbatch Formulation.

Claims

WHAT IS CLAIMED IS:1 . A method for making a colour masterbatch, the method comprising: mixing a colorant and an amphiphilic biodegradable polymer matrix to form a mixture, wherein the amphiphilic biodegradable polymer matrix is selected from the group consisting of PBAT-PEG, PHA-PEG, PCL-PEG, TPS-PHA, PBSA-PEG, TPS-PBAT, and TPS-PBS; and applying heat and torque to the mixture at a processing temperature sufficient to melt the amphiphilic biodegradable polymer matrix to make the colour masterbatch; wherein the colour masterbatch does not contain polylactic acid (PLA); and wherein the colour masterbatch is home compostable.

2. The method of claim 1 , further comprising: adding a grafted polymer to the mixture, wherein the grafted polymer is selected from the group consisting of maleic anhydride grafted PBAT, PBS, PHA, and PBSA .

3. The method of claim 1 , wherein the colorant and the amphiphilic biodegradable polymer matrix are mixed with a mixing speed of about 40-100 rpm and at a mixing temperature not exceeding 80°C.

4. The method of claim 1 , wherein the mixture is extruded via a twin-screw extruder with a screw speed of about 150-450 rpm and having a screw with a length-to-diameter ratio ranging from 37:1 to 50:1 and a diameter ranging from 18 mm to 120 mm.

5. The method of claim 4, wherein the mixture passes through the twin-screw extruder from a first zone with a temperature of about 85-95°C, to a second zone with a temperature of about 170-180°C, to a third zone with a temperature of about 180-200°C, to a fourth zone with a temperature of about 180-210°C, and to a fifth zone with a temperature of about 170- 200°C.

6. The method of claim 1 , wherein the colour masterbatch is cooled and pelletized.

7. The method of claim 1 , wherein the colorant is anthocyanin, thermochromic pigment, hydrochromic ink, fluorescein, leuco dye, or polydiacetylene with the ability to change colour in response to variations in pH and temperature.

8. The method of claim 1 , further comprising: modifying surfaces of silver nanoparticles, single-walled carbon nanotubes, carbon nanofibers, nanohydroxyapatite, nanocellulose, nanolignin, montmorillonite, graphene oxides, silica, kaolin clay, calcium carbonate, bentonite clay, cloisite clay, mica, wollastonite, or halloysite using a grafting agent selected from the group consisting of cetyltrimethylammonium bromide (CTAB), hexadecyl pyridinium chloride (HPC), sodium dodecyl sulfate (SDS), sodium oleate, Triton X-100™, polysorbate 80 (Tween 80™), dodecyldimethylamine oxide (DDAO), cocamidopropyl betaine, aminopropyltriethoxysilane (APTES), methacryloxypropyltrimethoxysilane (MPS), mercaptosilanes, epoxysilanes, citric acid, acrylic acid, oleic acid, organic acid, stearic acid, tetraalkoxy titanates, aluminum alkoxides, zirconium alkoxides, hexamethylene diisocyanate (HDI), maleic anhydride, aryl diazonium salts, glycidyl methacrylate (GMA), mercaptosilanes, and phosphonic acid derivatives; and adding the modified nanoparticle to the mixture.

9. The method of claim 1 , further comprising: adding to the mixture a cross-linking agent, an enzyme, an anti-microbial agent, an anti-microbial agent, and / or a UV stabilizer.

10. The method of claim 1 , further comprising: adding a microcapsule containing a healing agent to the mixture; wherein the healing agent is chitosan, alginate, a cellulose derivative, gelatin, or a combination thereof; wherein when the microcapsule ruptures, the healing agent is released and interacts with the amphiphilic biodegradable polymer matrix to initiate a self-repair process.

11. A colour masterbatch comprising: a colorant; andan amphiphilic biodegradable polymer matrix selected from the group consisting of PBAT-PEG, PHA-PEG, PCL-PEG, TPS-PHA, PBSA-PEG, TPS-PBAT, and TPS-PBS; wherein the colour masterbatch does not contain polylactic acid (PLA); and wherein the colour masterbatch is home compostable.

12. The colour masterbatch of claim 11 , further comprising a grafted polymer selected from the group consisting of maleic anhydride grafted PBAT, PBS, PHA, and PBSA.

13. The colour masterbatch of claim 11 , wherein the colorant is anthocyanin, thermochromic pigment, hydrochromic ink, fluorescein, leuco dye, or polydiacetylene with the ability to change colour in response to a variation in pH or temperature.

14. The colour masterbatch of claim 11 , further comprising a nanoparticle whose surfaces are modified using a grafting agent.

15. The colour masterbatch of claim 14, wherein the nanoparticle is silver nanoparticles, single-walled carbon nanotubes, carbon nanofibers, nanohydroxyapatite, nanocellulose, nanolignin, montmorillonite, graphene oxides, silica, kaolin clay, calcium carbonate, bentonite clay, cloisite clay, mica, wollastonite, or halloysite, the surfaces of which are modified using a grafting agent selected from the group consisting of cetyltrimethylammonium bromide (CTAB), hexadecylpyridinium chloride (HPC), sodium dodecyl sulfate (SDS), sodium oleate, Triton X-100™, polysorbate 80 (Tween 80™), dodecyldimethylamine oxide (DDAO), cocamidopropyl betaine, aminopropyltriethoxysilane (APTES), methacryloxypropyltrimethoxysilane (MPS), mercaptosilanes, epoxysilanes, citric acid, acrylic acid, oleic acid, organic acid, stearic acid, tetraalkoxy titanates, aluminum alkoxides, zirconium alkoxides, hexamethylene diisocyanate (HDI), maleic anhydride, aryl diazonium salts, glycidyl methacrylate (GMA), mercaptosilanes, and phosphonic acid derivatives.

16. The colour masterbatch of claim 11 , further comprising a cross-linking agent, an enzyme, an anti-microbial agent, an anti-microbial agent, and / or a UV stabilizer.

17. The colour masterbatch of claim 11 , further comprising a microcapsule containing a healing agent;wherein the healing agent is chitosan, alginate, a cellulose derivative, gelatin, or a combination thereof; wherein when the microcapsule ruptures, the healing agent is released and interacts with the amphiphilic biodegradable polymer matrix to initiate a self-repair process.

18. A method for making a colourized biodegradable polymer, the method comprising: introducing a colour masterbatch to a melt-processible biodegradable polymer to form a processable polymer composition, wherein the colour masterbatch comprises a colorant and an amphiphilic biodegradable polymer matrix selected from the group consisting of PBAT-PEG, PHA-PEG, PCL-PEG, TPS-PHA, PBSA-PEG, TPS-PBAT, and TPS-PBS; and processing the processable polymer composition to form the colourized biodegradable polymer.