Thermoplastic polymer-coal composites

Abstract

Embodiments described herein generally relate to a new class of composites that include LDPE and a coal-based material. The coal-based material may include coal char, coal powder, or combinations thereof. The coal-based material may serve as a functional filler for the composites. Articles of manufacture comprising composites described herein are also described.

Description

Thermoplastic Polymer-Coal CompositesFIELD

[0001] Embodiments described herein generally relate to a new class of composites that include a thermoplastic polymer and a coal -based material.BACKGROUND

[0002] There is significant interest in finding sustainable and environmental - friendly ways to utilize coal is of significant interest. Coal has been employed as a feedstock to prepare specialty materials, such as graphene, carbon fiber, carbon nanotubes, activated carbon, carbon electrodes, and as a feedstock in rare earth element extraction. Carbon nanotubes from pyrolysis of coal have been investigated. The development of graphene and graphene oxide from low-grade coal, such as Powder River Basin, as well as the coal extracts as the polyol component for the polyurethane coatings, have been investigated. However, conversion of coal to these products requires several stages of treatments and different chemical reagents at high temperatures / pressures.

[0003] There is a need for new composites containing coal. There is also a need for applications of coal with minimum (or no) treatment or processing operations.SUMMARY

[0004] Embodiments described herein generally relate to a new class of composites that include a thermoplastic polymer and a coal -based material. The coal -based material, which may be coal, coal powder, coal char, and / or or coal -based material, may serve as a functional filler for the composites. The coal -based material is less processed than conventional coal -based materials. That is, unlike conventional approaches which utilize heavily processed coal-based materials requiring several treatment stages and different chemical reagents at high temperatures and pressures, embodiments described herein may utilize coal-based materials that are free of several treatment stages. In addition, the composites containing the coal-based material may have improve physical properties over conventional composites.

[0005] In an embodiment is provided a composite that includes a thermoplastic polymer and a coal -based material.

[0006] In another embodiment is provided an article of manufacture that includes a composite described herein.

[0007] In another embodiment is provided a container that includes a composite described herein.

[0008] In another embodiment is provided automotive part that includes a composite described herein.

[0009] In another embodiment is provided a method of forming a composite. The method includes processing a mixture comprising a thermoplastic polymer and a coalbased material to form a composite described herein.

[0010] In another embodiment is provided a method of forming a composite. The method includes processing a mixture comprising a thermoplastic polymer and a coalbased material to form a composite, the coal-based material comprising coal char, coal powder, or combinations thereof, the composite having: a density that is from about 0.945 kg / L to about 1.03 kg / L; an elongation at break that is greater than 10%; or combinations thereof.BRIEF DESCRIPTION OF THE DRAWINGS

[0011] So that the manner in which the above recited features of the present disclosure may be understood in detail, a more particular description of the disclosure, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only exemplary embodiments and are therefore not to be considered limiting of its scope, and may admit to other equally effective embodiments.

[0012] FIG. 1A shows mixing torque traces for example composites and comparative examples according to at least one embodiment of the present disclosure.

[0013] FIGS. 1B-1F show mixing traces for example composites and comparative examples according to at least one embodiment of the present disclosure.

[0014] FIG. 2A is an optical image of an example composite that includes low density polyethylene (LDPE) and coal powder (LDPE / coal powder) according to at least one embodiment of the present disclosure.

[0015] FIG. 2B is a scanning electron microscope (SEM) three dimensional (3D) surface roughness map of an example composite (LDPE / coal powder) according to at least one embodiment of the present disclosure.

[0016] FIG. 2C is an optical image of an example composite (LDPE / coal char) according to at least one embodiment of the present disclosure.

[0017] FIG. 2D is a SEM 3D surface roughness map of an example composite (LDPE / coal char) according to at least one embodiment of the present disclosure.

[0018] FIG. 2E is an optical image of a comparative example composite (LDPE / N550 carbon black).

[0019] FIG. 2F is a SEM 3D surface roughness map of a comparative example composite (LDPE / N550 carbon black).

[0020] FIG. 2G is an optical image of a comparative example composite (LDPE / N660 carbon black).

[0021] FIG. 2H is a SEM 3D surface roughness map of a comparative example composite (LDPE / N660 carbon black).

[0022] FIG. 3A is a SEM image of an example composite (LDPE / coal powder) according to at least one embodiment of the present disclosure.

[0023] FIG. 3B is a SEM image of an example composite (LDPE / coal char) according to at least one embodiment of the present disclosure.

[0024] FIG. 3C is a SEM image of a comparative example composite (LDPE / N550 carbon black).

[0025] FIG. 3D is a SEM image of a comparative example composite (LDPE / N660 carbon black).

[0026] FIG. 4A is a stress / strain plot of an example composite (LDPE / coal powder) according to at least one embodiment of the present disclosure.

[0027] FIG. 4B is a stress / strain plot of an example composite (LDPE / coal char) according to at least one embodiment of the present disclosure.

[0028] FIG. 4C is a stress / strain plot of a comparative example composite (LDPE / N550 carbon black).

[0029] FIG. 4D is a stress / strain plot of a comparative example composite (LDPE / N660 carbon black).

[0030] FIG. 4E is a stress / strain plot of a comparative example (LDPE alone).

[0031] To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation.DETAILED DESCRIPTION

[0032] Embodiments described herein generally relate to a new class of composites that include a thermoplastic polymer and a coal -based material. The coal -based material of composites described herein may include coal or a coal-derived product such as coal char, coal powder, or combinations thereof. The inventors found that a coal-based material may be utilized in composites as, for example, a functional filler. As a functional filler in composites, the inventors found that the coal-based material may serve as a reinforcement and / or as a thermal stabilizer to the thermoplastic polymer. Composites described herein may be utilized for a variety of applications including playground equipment, containers (such as waste containers), non-critical engineering structures, automotive parts, housings, boxes, and plastic parts, among other applications. Composites described herein may be used instead of articles conventionally manufactured using a thermoplastic polymer alone.

[0033] The use of headings is for purposes of convenience only and does not limit the scope of the present disclosure. Embodiments described herein may be combined with other embodiments.

[0034] As described above, there is significant interest in finding sustainable and environmental-friendly ways to utilize coal. Conventionally, coal has been employed as a feedstock to prepare specialty materials, such as graphene, carbon fiber, carbon nanotubes, activated carbon, carbon electrodes, and to extract rare earth elements. However, conversion of coal to these products requires several stages of treatments and different chemical reagents at high temperatures / pressures. Therefore, there is a need for applications of coal-based materials (e.g., coal or coal-derived products) at large scales and where the coal-derived product is made with minimum treatment or processing operations.

[0035] To this end, the inventors demonstrate use of coal-based materials as, for example, a reinforcement / filler in composites with thermoplastic polymers. Advantageously, this novel composite is free of those issues / challenges described for the conversion of coal to other coal-based products. Composites described herein may be utilized as a replacement for thermoplastic composites (or other composites) used for various applications. Here, for example, it was found that composites described herein show improved properties — such as mechanical, physical, melt viscoelastic, and thermal behavior — over conventional composites.

[0036] Embodiments of the present disclosure generally relate to composites. Composites described herein may include a thermoplastic polymer. The composite further includes a coal-based material such as coal or a coal-derived material. For example, composites may include a thermoplastic polymer and coal char. Alternatively, composites may include a thermoplastic polymer and coal powder. Alternatively, composites may include a thermoplastic polymer, coal char, and coal powder.

[0037] Optionally, composites described herein may include one or more additives. Additives may include, but are not limited to compatibilizers. When the composition includes a compatibilizer, the compatibilizer may be present in an amount that is from greater than 0 wt% to about 0.1 wt% or less of compatibilizer based on a total weight of the composite. In some embodiments, which may be combined with other embodiments, composites described herein may be free of added compatibilizer, free of added flame retardant, or free of added compatibilizer and free of added flame retardant.

[0038] The coal char and / or coal powder may be incorporated into or otherwise dispersed in the polymer system / matrix to form a composite. The carbon incorporated (from the coal char or powder) may serve to modify and / or improve various mechanical properties such as tensile strength, stiffness, hardness, and strength. The coal derived pyrolysis char as well as the coal powder is an inexpensive way to reinforce polymers, especially relative to conventional approaches to reinforce polymers.

[0039] The coal char may be produced by any suitable method. The coal char may be pyrolysis char, such as pyrolyzed char, flash pyrolyzed char, or combinations thereof. Coal char produced through the process of pyrolysis essentially drives off organic material leaving behind a solid fixed carbon material. In the case of pyrolyzing high oxygen content coals, such as subbituminous varieties, of which Powder River Basin coal (PRB) is an example, the nature of the char may exhibit unique functional properties.

[0040] The produced pyrolysis char from, e.g., sub-bituminous coal, is both very high quality with minimum contamination. Pyrolysis char produced from PRB coal exhibits measurable mechanical (tensile and compressive) and the structure is highly porous. While not visible to the naked eye, this micro-porosity may be developed and properties changed either through changing operational parameters during the pyrolysisprocess e.g. temperature pyrolyzed, residence time, as well as particulate size and shape of the coal feedstock entering the pyrolyzer. Further, the pore structure of the pyrolysis char may be influenced by changing the surface hydrophobicity / hydrophilic behavior, for example, by washing in a solvent such as butanol and / or methanol, which reacts with free oxygen radicals. Oxidation of the surface with ozone or hydrogen peroxide may also change surface properties including influencing the surface area to volume ratio and size of pores. The shape and size of the feedstock being pyrolyzed may also influence the shape of the resulting char.

[0041] As described herein, the fixed carbon char resulting from pyrolysis possesses valuable engineering properties which may be further customized, such as by modification and control over their particle size distribution. The pyrolysis char may be incorporated and dispersed in polymer systems to form a composite. The carbon incorporated into the composite serves to, for example, reinforce the composite by modifying and improving mechanical properties such as tensile strength, stiffness and hardness, thereby increasing strength.

[0042] In some examples, embodiments described herein include modifying the milling regime to reduce particle size distributions of the coal-based material (e.g., coal powder and / or coal char). In some examples, embodiments of the present disclosure include a surface activation process to add oxygen functional groups to the surface of the coal-based material. The effects of particle size and surface chemistry on dispersion in the polymer matrix as well as the mechanical properties of the composite may impact performance.

[0043] Coal char is a residue obtained from the pyrolysis of coal. Any suitable coal char may be utilized with embodiments described herein. For example, coal may be sourced from, e.g., Powder River Basin (PRB) (a subbituminous coal), and then subjected to pyrolysis at suitable temperatures such as from about 600°C to about l,000°C, such as from about 700°C to about 900°C, such as about 850°C. The coal char may be pyrolyzed for any suitable time such as about 24 hours or less, such as about 12 hours or less, such as about 8 hours or less, such as about 5 hours or less, such as about 3 hours or less, such as about 2 hours or less, such as about 1 hour or less.

[0044] Others types of coal char are contemplated. For example, coal charthat may be used includes, but is not limited to, coal char prepared by flash pyrolysis. Coal charproduced by flash pyrolysis may be prepared by heating coal at a temperature that is from about 600°C to about l,000°C for a duration of about 1 hour or less, such as about 5 minutes or less, such as about 30 seconds or less, such as about 5 seconds or less, such as about 1 second. In some embodiments, which may be combined with other embodiments, the flash pyrolysis coal char may be made with the aforementioned flash pyrolysis in addition to a pre-pyrolysis operation. Pre-pyrolysis operations may have a duration of about 15 minutes and may be any suitable pre-pyrolysis operation.

[0045] Coal char useful for composites described herein may include flash pyrolysis coal char. Flash pyrolysis coal char is made with significantly shorter pyrolysis times than, at least, metallurgical coke and petroleum coke.

[0046] Coal char may have any suitable particle size. For example, and in some embodiments, the coal char may have an average particle size that is about 100 pm or less, such as about 80 pm or less, such as about 60 pm or less, such as about 40 pm or less, such as about 20 pm or less, such as about 10 pm or less, such as about 5 pm or less, such as from about 1 pm to about 2 pm, though other sizes are contemplated. Any of the foregoing numbers may be used singly to describe an open-ended range or in combination to describe a close-ended range.

[0047] One or more types of coal char may be utilized for composites described herein. For example, the coal char used composites of the present disclosure may be polydisperse such that particles of the coal char are not of the same size but of different sizes. In various implementations, the coal char used in a composite may have a high level of particles in the 1-2 micron range.

[0048] An amount of coal char in composites described herein may be from about 1 weight percent (wt%) to about 99 wt%, such as from about 5 wt% to about 80 wt%, such as from about 10 wt% to about 60 wt%, such as from about 15 wt% to about 55 wt%, such as from about 20 wt% to about 50 wt%, such as from about 25 wt% to about 45 wt%, from about 30 wt% to about 40 wt%, or from about 20 wt% to about 30 wt%, or from about 20 wt% to about 25 wt%, or from about 20 wt% to about 70 wt%, or about 40 wt% or more, such as from about 40 wt% to about 80 wt%, such as from about 40 wt% to about 60 wt%, based on a total amount of the thermoplastic polymer and coal-based material (e.g., coal char, coal powder, or combinations thereof) in the composite, the total amount of the thermoplastic polymer and coal-based material inthe composite does not exceed 100 wt%. Other amounts are contemplated. Any of the foregoing numbers may be used singly to describe an open-ended range or in combination to describe a close-ended range.

[0049] Additionally, or alternatively, coal (such as coal powder) may be utilized in composites of the present disclosure.

[0050] Coal powder useful in composites described herein may have any suitable particle size. For example, coal powder may have an average particle size that is about 100 pm or less, such as from about 20 pm to about 90 pm, such as from about 30 pm to about 80 pm, such as from about 40 pm to about 60 pm, though other sizes are contemplated. Any of the foregoing numbers may be used singly to describe an open- ended range or in combination to describe a close-ended range.

[0051] One or more types of coal powder may be utilized for composites described herein. For example, the coal powder used with composites of the present disclosure may polydisperse such that particles of the coal powder are not of the same size but of different sizes. In various implementations, the coal powder used in a composite may have a bimodal particle size distribution with peaks at about 10 pm and about 100 pm.

[0052] An amount of coal powder in composites described herein may be from about 1 wt% to about 99 wt%, such as from about 5 wt% to about 80 wt%, such as from about 10 wt% to about 60 wt%, such as from about 15 wt% to about 55 wt%, such as from about 20 wt% to about 50 wt%, such as from about 25 wt% to about 45 wt%, such as from about 30 wt% to about 40 wt%, or from about 20 wt% to about 70 wt%, or about 40 wt% or more, such as from about 40 wt% to about 80 wt%, such as from about 40 wt% to about 60 wt%, based on a total amount of the thermoplastic polymer and coal-based material (e.g., coal char, coal powder, or combinations thereof) in the composite, the total amount of the thermoplastic polymer and coal-based material in the composite does not exceed 100 wt%. Other amounts are contemplated. Any of the foregoing numbers may be used singly to describe an open-ended range or in combination to describe a close-ended range.

[0053] As described herein, the coal -based material (for example, coal char and / or coal powder) may serve as a reinforcement and / or a filler such as a diluent filler. As a filler or diluent filler, the coal-based material may replace conventional fillers and diluent fillers such as calcium carbonate, carbon black, and other fillers.

[0054] Any suitable thermoplastic polymer may be utilized for composites described herein. Suitable thermoplastic polymers include those prepared by polymerization of olefin-containing monomers. Suitable thermoplastic polymers may include a polyethylene (such as LDPE), polypropylene (PP), acrylonitrile butadiene styrene (ABS), nylon, polyvinyl chloride, or combinations thereof.

[0055] When the thermoplastic polymer of composites described herein includes LDPE, the LDPE of composites described herein may have a density that is about 0.910 g / cm3or more. LDPE utilized for embodiments described herein may have a density that is from about 0.910 g / cm3to about 0.940 g / cm3, such as from about 0.915 g / cm3to about 0.935 g / cm3, such as from about 0.92 g / cm3to 0.93 g / cm3, such as from about 0.92 g / cm3to about 0.925 g / cm3or from about 0.925 g / cm3to about 0.93 g / cm3, though other densities are contemplated. Any of the foregoing numbers may be used singly to describe an open-ended range or in combination to describe a close-ended range.

[0056] When the thermoplastic polymer of composites described herein includes LDPE, the HDPE the LDPE may have any suitable melt flow index (MFI, 190°C / 2.16 kg). For example, the LDPE may have a melt flow index that is from about 0.3 g / 10 min to about 3 g / 10 min, such as from about 0.5 g / 10 min to about 2.3 g / 10 min, such as from about 0.8 g / 10 min to about 2 g / 10 min, such as from about 1 g / 10 min to about 1.8 g / 10 min, such as from about 1.2 g / 10 min to about 1.6 g / 10 min, though other MFIs are contemplated. Any of the foregoing numbers may be used singly to describe an open-ended range or in combination to describe a close-ended range.

[0057] One or more types of LDPE may be utilized for composites described herein.

[0058] The composites may include any suitable amount of thermoplastic polymer. An amount of the thermoplastic polymer (such as LDPE) in composites described herein may be from about 1 wt% to about 99 wt%, such as from about 20 wt% to about 95 wt%, such as from about 40 wt% to about 90 wt%, such as from about 45 wt% to about 85 wt%, such as from about 50 wt% to about 80 wt%, such as from about 55 wt% to about 75 wt%, from about 60 wt% to about 80, or from about 70 wt% to about 80 wt%, or from about 30 wt% to about 80 wt%, or about 60 wt% or less, such as from about 20 wt% to about 60 wt%, such as from about 40 wt% to about 60 wt%, based on the total amount thermoplastic polymer and coal-based material (e.g., coal char, coalpowder, or combinations thereof) in the composite. Other amounts are contemplated. Any of the foregoing numbers may be used singly to describe an open-ended range or in combination to describe a close-ended range.

[0059] Composites described herein may include from about 5 to about 70 parts of coal -based material (coal char, coal powder, or combinations thereof) to 100 parts of thermoplastic polymer (such as LDPE) , such as from about 10 to about 55 parts of coal -based material to 100 parts of thermoplastic polymer, such as from about 15 to about 45 parts of coal -based material to 100 parts of thermoplastic polymer, such as from about 20 to about 40 parts of coal -based material to 100 parts of thermoplastic polymer, such as from about 25 to about 35 parts of coal -based material to 100 parts of thermoplastic polymer, such as about 30 parts of coal -based material to 100 parts of thermoplastic polymer.

[0060] Composites described herein may have an average surface roughness (Ra) that is greater than 0.55 pm and less than 2 pm, such as from about 0.6 pm to about 1.8 pm, such as from about 0.7 pm to about 1.6 pm, such as from about 0.8 pm to about 1.5 pm, such as from about 0.9 pm to about 1.4 pm, such as from about 0.95 pm to about 1.35 pm, such as from about 0.99 pm to about 1.3 pm, such as from about 1 pm to about 1.25 pm, such as from about 1.05 pm to about 1.2 pm, such as from about 1.1 pm to about 1.15 pm, though other values are contemplated. Any of the foregoing numbers may be used singly to describe an open-ended range or in combination to describe a close-ended range.

[0061] Composites described herein may have an average maximum profile peak height (Rpm) that is greater than 1.6 pm and less than 4.2 pm, such as from about 1.7 pm to about 4.0 pm, such as from about 1.9 pm to about 3.9 pm, such as from about 2.1 pm to about 3.8 pm, such as from about 2.3 pm to about 3.7 pm, such as from about 2.4 pm to about 3.6 pm, such as from about 2.5 pm to about 3.55 pm, such as from about 2.7 pm to about 3.5 pm, such as from about 2.9 pm to about 3.45 pm, such as from about 3.1 pm to about 3.4 pm, such as from about 3.2 pm to about 3.35 pm, such as from about 3.3 pm to about 3.35 pm, though other values are contemplated. Any of the foregoing numbers may be used singly to describe an open-ended range or in combination to describe a close-ended range.

[0062] Composites described herein may have a density that is from about 0.945 kg / L to about 1.03 kg / L, such as from about such as from about 0.98 kg / L to about 1.02 kg / L, such as from about 1.0 kg / L to about 1.015 kg / L, though other values are contemplated. Any of the foregoing numbers may be used singly to describe an open- ended range or in combination to describe a close-ended range.

[0063] Composites described herein may have an elongation at break that is greater than 10%, such as from about 15% to about 300%, such as from about 20% to about 200%, such as from about 25% to about 150%, such as from about 40% to about 125%, such as from about 50% to about 100%, though other values are contemplated. Any of the foregoing numbers may be used singly to describe an open-ended range or in combination to describe a close-ended range.

[0064] Composites described herein may have a Shore D hardness that is from 50 to 54, such as from 51 to 53, though other values are contemplated. Any of the foregoing numbers may be used singly to describe an open-ended range or in combination to describe a close-ended range.

[0065] Composites described herein may have a Young’s modulus that is from about 50 MPa to about 100 MPa, such as from about 60 MPa to about 90 MPa, such as from about 70 MPa to about 80 MPa, such as from about 72 MPa to about 76 MPa, though other values are contemplated. Any of the foregoing numbers may be used singly to describe an open-ended range or in combination to describe a close-ended range.

[0066] Embodiments described herein may be utilized for a variety of applications and uses. Non-limiting applications or uses of composites described herein may include playground equipment, containers (such as waste containers), non-critical engineering structures, automotive parts, housings, boxes, and plastic parts. Other applications are contemplated. Here, for example, composites described herein may be used instead of articles conventionally manufactured using thermoplastic polymers alone, such as those articles conventionally manufactured using polyethylene, PP, ABS, or nylon alone. In addition, compositions described herein may be used in applications where carbon black, carbon, or glass fiber are conventionally utilized, such as automotive and industrial applications.

[0067] In some embodiments, composites described herein may be useful for applications where strength and / or rigidity characteristics are desired, but not necessarily flexibility. However, it is contemplated that composites described herein may be useful for applications where flexibility is desired.

[0068] The following examples are put forth so as to provide those of ordinary skill in the art with a complete disclosure and description of how to make and use aspects of the present disclosure, and are not intended to limit the scope of aspects of the present disclosure. Efforts have been made to ensure accuracy with respect to numbers used (e.g. amounts, dimensions, etc.) but some experimental errors and deviations should be accounted for.Examples

[0069] Composites were made using LDPE and a coal -based material. Two PRB coal-derived carbon particle types — coal char and coal powder — were utilized as a filler or reinforcement to form novel LDPE polymer composites. The performance of LDPE composites described herein was compared with conventional LDPE composites made with standard grades of furnace carbon black, N550 and N660.

[0070] The inventors found that the addition of coal -based materials, which may be milled to match nominal carbon black particle sizes, to LDPE (as an example thermoplastic polymer) may result in increases in both tensile strength and modulus with a reduction in elongation at break (i.e., the elasticity of the composite may be reduced compared to pure LDPE) relative to LDPE alone. When compared to the carbon black-filled samples, the coal -based fillers of the present disclosure may provide composites having higher strengths with the same or slightly lower moduli. In addition, coal-based composites may fail in a ductile mode (less catastrophically), while the carbon black composites displayed brittle failures. Overall, the coal-based LDPE composites show improved mechanical properties over N550 and N660 carbon black filled materials.Preparation of Example Composites

[0071] Compounding. Milled coal powder, coal char, and two virgin carbon blacks (N550 and N660) were mixed into LDPE at a ratio of 100 parts polymer: 30 parts filler using a HAAKE Rheomix OS / 610 of 310 cm3chamber volume with plastic-mixing rollers set at 165°C and 90 rpm, following the mixing procedure outlined in Table 1.Table 1

[0072] An LDPE unfilled control sample was also subjected to the same mixing cycle and tested as a control. The example composites (Ex. 1 and Ex. 2), the comparative example composites (C.Ex. 1 and C.Ex. 2), and the control were given the sample names shown in Table 2.Table 2

[0073] Moulding. Test sheets, about 2 mm thick, were moulded at a temperature of 160°C. The materials were pre-heated in the press under contact pressure before full pressure (80 tonnes) was applied, with two bumps to allow trapped air to escape. The samples were held at 160°C for 3 minutes and then transferred to a water-cooled press. A ram pressure of -250 psi was applied and maintained until the sample had cooled to room temperature.Characterization

[0074] Dispersion Assessment. Sections of composite were prepared using fresh razor blades and imaged using optical microscopy at *5 magnification under dark field lighting. Surface roughness maps (*250 magnification) were generated using a Hitachi TM3030 scanning electron microscope (SEM) fitted with an annular multi -segmented back- scattered electron detector.

[0075] Density. Density was determined following BSISO 2781+A1.

[0076] Hardness. Shore D hardness was tested according to BS ISO 48-4, 3 s load time.

[0077] Tensile Properties. Tensile strength and elongation at break were determined using BS ISO 37 Type 1 dumbbells tested at 100 mm / min, with strain measured using laser extensometry. A pre-load of 2 N was applied at a speed of 60mm / min. However, this method was unable to accurately measure Young’s modulus and, instead, this was determined using rectangular strips, approximately 10 x 125 mm, which were tested at 1 mm / min, with a preload of 10N, also applied at Imm / min. Strain was measured using a clip-on extensometer and Young’s modulus was determined as the chord modulus between 1 and 3% strain.Non-Limiting ResultsMixing Traces

[0078] Torque traces of the example composites, the comparative example composites, and the control are shown in FIG. 1 A and full mixing traces are shown in FIGS. 1B-1F. These figures show some differences between the composite samples containing coal-based materials and composite samples containing carbon blacks, particularly from when the fillers are first added (after 60 seconds) until, roughly, 130 seconds (s) after the start. The peak torques are also higher for the composite samples containing carbon blacks. Overall, the traces suggest that the coal samples may be less easy to mix into the LDPE polymer than the carbon blacks.Dispersion

[0079] Following compounding into the LDPE, the filler dispersion levels achieved with the composite samples containing coal-based materials were assessed. Optical images and SEM 3D surface roughness maps of the example composites and the comparative example composites are shown in FIGS. 2A-2H. These optical images andSEM 3D surface roughness maps indicated that the coal char sample was better dispersed in the LDPE matrix than the coal powder sample and appeared to be improved over, or similar to, the N550 and N660 carbon black comparative example composites.

[0080] The SEM images of FIGS. 3A-3D show that the particle sizes of the coal samples were significantly larger than the carbon blacks, with the coal powder particles being bigger than the coal char particles. This result is confirmed by the values of Ra (roughness average) and Rpm (average maximum profile peak height), calculated at *250 magnification as the average of five measurements, which are given in Table 3. The standard deviations determined for these measurements are also larger for the coal samples, suggesting that the particle size distribution is also broader than for the carbon black samples (approximate averages 0.5 to 0.01 pm).Table 3: Surface roughness parameters of filled compositesPhysical Properties

[0081] Table 4 shows selected physical properties of the composites.Table 4

[0082] The densities of the two coal sample-filled composites were determined to be lower than those of the carbon black-filled composites by about 4 wt%. While not wishing to be bound by any theory, this result may reflect differences in the densities of the fillers themselves. The greater level of porosity in the coal char is consistent with this explanation or the presence of interfacial voids which are present post-mixing. The lower density of the coal-filled two composites may also explain their increased difficulty of mixing. However, microscopic images and tensile results suggest that any porosity may be minimal. The values of hardness may be higher than the unfilled LDPE and may lie between the two carbon black-filled composites.

[0083] For the tensile properties, two measures of strength are reported: for the coal powder-filled sample (Ex. 1), the coal char-filled sample (Ex. 2), and the unfilled sample (control), ultimate tensile strength is reported as the maximum stress before necking occurred. For the carbon black-filled samples, the fracture strength is reported. The full set of tensile data is shown in Table 5. Stress / strain plots for the samples are shown in FIGS. 4A-4E. In Table 5, the notation “(med)” refers to the median value for the property.Table 5

[0084] Overall, the results shown in Table 5 indicate that composites of the present disclosure have improved properties over conventional composites and LDPE alone. For example, the addition of either the coal powder or the coal char to the LDPE resulted in a composite having an increase in ultimate tensile strength and Young’s modulus relative to the LDPE alone, but a reduction in elongation at break - i.e., the elasticity has been reduced. Relative to the comparative example composites, the example composites had a higher elongation at break (all greater than 15%). In addition, the example composites of the present disclosure exhibited ductile failure, and in contrast, the carbon black-filled samples exhibited mainly brittle failures, with higher values of modulus but lower values of strength and elongation at break. These results indicate that composites of the present disclosure have less catastrophic failure than the comparative example composites.

[0085] It was determined that the addition of a coal-based material — coal powder or coal char — to LDPE resulted in an increase in both tensile strength and modulus but a reduction in elongation at break relative to LDPE alone. When compared to the carbon black-filled samples, and under the conditions tested, the coal-based materials may provide higher strengths but may have slightly lower moduli. The coal -based samples may fail in ductile mode (i.e., less catastrophically), whilst the carbon black samples mainly displayed brittle failures.

[0086] The optical images and SEM 3D surface roughness maps indicated that the coal char may be better dispersed in the LDPE polymer matrix than the coal powder sample. In addition, and relative to the carbon black samples, the coal char may show improved (or comparable) dispersion in the LDPE polymer matrix. The particle size distribution (PSD) of the coal char may center around 1 pm to 2 pm which is near to that of commercial carbon blacks (0.5 pm to 0.01 pm). The particle sizes of the coal powder are larger than the coal char.

[0087] Embodiments described herein generally relate to composites that include a thermoplastic polymer and a coal -based material. Results provided herein demonstrate that coal char (which is the product of pyrolysis of coal) and coal powder may be used in polymer composites as, for example, a functional filler. Composites described herein may be used in a variety of applications or uses such as playground equipment, containers (such as waste containers), non-critical engineering structures, automotive parts, housings, boxes, and plastic parts, among others. Here, for example, composites described herein may be used instead of articles conventionally manufactured using thermoplastics alone (such as LDPE alone or PP alone, among other thermoplastics). In addition, it was found that coal char useful for composites described herein may include flash pyrolysis coal char. Flash pyrolysis coal char is made with significantly shorter pyrolysis times than, at least, metallurgical coke and petroleum coke.Embodiments Listing

[0088] The present disclosure provides, among others, the following aspects, each of which can be considered as optionally including any alternate embodiments:

[0089] Clause 1. A composite, comprising: a thermoplastic polymer; and a coalbased material.

[0090] Clause 2. The composite of Clause 1, wherein the thermoplastic polymer comprises a thermoplastic polymer formed from polymerization of olefin-containing monomers.

[0091] Clause 3. The composite of any one of Clauses 1 or 2, wherein the thermoplastic polymer comprises low density polyethylene, polypropylene, acrylonitrile butadiene styrene (ABS), nylon, polyvinyl chloride, or combinations thereof.

[0092] Clause 4. The composite of any one of Clauses 1-3, wherein the thermoplastic polymer comprises low density polyethylene, polypropylene, or combinations thereof.

[0093] Clause 5. The composite of any one of Clauses 1-4, wherein the composite comprises: from about 20 wt% to about 70 wt% of the coal -based material based on a total amount of the thermoplastic polymer and the coal-based material in the composite, the total amount of the thermoplastic polymer and the coal-based material in the composite not to exceed 100 wt%.

[0094] Clause 6. The composite of any one of Clauses 1-5, wherein the composite comprises: from about 40 wt% to about 60 wt% of the coal -based material based on a total amount of the thermoplastic polymer and the coal-based material in the composite, the total amount of the thermoplastic polymer and the coal-based material in the composite not to exceed 100 wt%; and from about 60 wt% to about 40 wt% of the thermoplastic polymer based on the total amount of the thermoplastic polymer and the coal-based material in the composite.

[0095] Clause 7. The composite of any one of Clauses 1-6, wherein the coal -based material comprises coal char, coal powder, or combinations thereof.

[0096] Clause 8. The composite of any one of Clauses 1-7, wherein the composite comprises from about 20 to about 40 parts of the coal -based material to 100 parts of the thermoplastic polymer.

[0097] Clause 9. The composite of any one of Clauses 1-8, wherein the coal -based material comprises pyrolyzed coal, flash pyrolyzed coal, or combinations thereof.

[0098] Clause 10. The composite of any one of Clauses 1-9, wherein the coal -based material comprises a subbituminous coal -based material.

[0099] Clause 11. The composite of any one of Clauses 1-10, wherein the composite is free of added compatibilizer.

[0100] Clause 12. The composite of any one of Clauses 1-11, wherein the composite further comprises from greater than 0 wt% to about 0.1 wt% or less of compatibilizer.

[0101] Clause 13. The composite of any one of Clauses 1-12, wherein the composite is free of added flame retardant.

[0102] Clause 14. The composite of any one of Clauses 1-13, wherein the composite has: a density that is from about 0.945 kg / L to about 1.03 kg / L; an elongation at break that is greater than 10%; a Shore D hardness that is from 50 to 54; a Young’s modulus that is from about 50 MPa to about 100 MPa; or combinations thereof.

[0103] Clause 15. An article of manufacture, comprising the composite of any one of Clauses 1-14.

[0104] Clause 16. A container, comprising the composite of any one of Clauses 1- 14.

[0105] Clause 17. An automotive part, comprising the composite of any one of Clauses 1-14.

[0106] Clause 18. A method of forming a composite, the method comprising: processing a mixture comprising a thermoplastic polymer and a coal -based material to form a composite described herein, the processing optionally comprises: heating the low density polyethylene and the coal -based material to a temperature that is from about 100°C to about 200°C (such as from about 120°C to about 180°C, such as from about 140°C to about 170°C, such as about 165°C) with stirring at a rate that is from about 50 rpm to about 150 rpm (such as from about 70 rpm to about 120 rpm, such as from about 80 to about 100 rpm, such as about 90 rpm).

[0107] Clause 19. The method of Clause 18, wherein: the thermoplastic polymer comprises low density polyethylene; the coal -based material comprises coal char, coal powder, or combinations thereof; or combinations thereof.

[0108] Clause 20. The method of any one of Clauses 18 or 1919, wherein, when the coal-based material comprises the coal char, the coal char comprises pyrolyzed coal, flash pyrolyzed coal, or combinations thereof.

[0109] Clause 21. A method of forming a composite, the method comprising: processing a mixture comprising low density polyethylene and a coal -based material to form a composite, the coal-based material comprising coal char, coal powder, or combinations thereof, the composite having: a density that is from about 0.945 kg / L to about 1.03 kg / L; an elongation at break that is greater than 10%; or combinations thereof.

[0110]

[0111] Clause 22. A composite, comprising: low density polyethylene; and a coalbased material.

[0112] Clause 23. The composite of Clause 22, wherein the coal -based material comprises coal char, coal powder, or combinations thereof.

[0113] Clause 24. The composite of any one of Clauses 22 or 23, wherein the coalbased material comprises pyrolyzed coal, flash pyrolyzed coal, or combinations thereof.

[0114] Clause 25. The composite of any one of Clauses 22-24, wherein the composite has: an average surface roughness (Ra) value that is greater than 0.55 pm; an average maximum profile peak height (Rpm) value that is greater than 1.7 pm; or combinations thereof.

[0115] Clause 26. The composite of any one of Clauses 22-25, wherein the composite has: an average surface roughness (Ra) value that is greater than 0.8 pm; an average maximum profile peak height (Rpm) value that is greater than 2.4 pm; or combinations thereof.

[0116] Clause 27. The composite of any one of Clauses 22-26, wherein the composite has: a density that is from about 0.945 kg / L to about 1.03 kg / L; an elongation at break that is greater than 10%; a Shore D hardness that is from 50 to 54; a Young’s modulus that is from about 50 MPa to about 100 MPa; or combinations thereof.

[0117] Clause 28. The composite of any one of Clauses 22-27, wherein the composite has: a density that is from about 0.945 kg / L to about 1.03 kg / L; an elongation at break that is greater than 10%; a Shore D hardness that is from 50 to 54; and a Young’s modulus that is from about 50 MPa to about 100 MPa.

[0118] Clause 29. The composite of any one of Clauses 22-28, wherein the composite comprises interfacial voids.

[0119] Clause 30. The composite of any one of Clauses 22-29, wherein the coalbased material comprises a subbituminous coal-based material.

[0120] Clause 31. The composite of any one of Clauses 22-30, wherein the low density polyethylene has a density that is from about 0.91 g / cm3to about 0.940 g / cm3.

[0121] Clause 32. The composite of any one of Clauses 22-31, wherein the low density polyethylene has a melt flow index (190°C / 2.16 kg) that is from about 0.3 g / 10 min to about 3 g / 10 min.

[0122] Clause 33. The composite of any one of Clauses 22-32, wherein the composite comprises from about 10 to about 55 parts of the coal -based material to 100 parts of the low density polyethylene.

[0123] Clause 34. The composite of any one of Clauses 22-33, wherein the composite comprises from about 20 to about 40 parts of the coal -based material to 100 parts of the low density polyethylene.

[0124] Clause 35. The composite of any one of Clauses 22-34, wherein composite further comprises acrylonitrile butadiene styrene, nylon, or combinations thereof.

[0125] Clause 36. An article of manufacture, comprising the composite of any one of Clauses 22-35.

[0126] Clause 37. A container, comprising the composite of any one of Clauses 22- 35.

[0127] Clause 38. An automotive part, comprising the composite of any one of Clauses 22-35.

[0128] Clause 39. A method of forming a composite, the method comprising: processing a mixture comprising low density polyethylene and a coal -based material to form a composite, the coal-based material comprising coal char, coal powder, or combinations thereof, the composite having: a density that is from about 0.945 kg / L to about 1.03 kg / L; an elongation at break that is greater than 10%; or combinations thereof.

[0129] Clause 40. The method of Clause 39, wherein, when the coal-based material comprises the coal char, the coal char comprises pyrolyzed coal, flash pyrolyzed coal, or combinations thereof.

[0130] Clause 41. The method of any one of Clauses 39 or 40, wherein the composite comprises from about 10 to about 55 parts of the coal -based material to 100 parts of the low density polyethylene.

[0131] Clause 42. The method of any one of Clauses 39-41, wherein the processing comprises: heating the low density polyethylene and the coal-based material to a temperature that is from about 100°C to about 200°C (such as from about 120°C to about 180°C, such as from about 140°C to about 170°C, such as about 165°C) with stirring at a rate that is from about 50 rpm to about 150 rpm (such as from about 70 rpm to about 120 rpm, such as from about 80 to about 100 rpm, such as about 90 rpm).

[0132] All documents described herein are incorporated by reference herein, including any priority documents and / or testing procedures to the extent they are not inconsistent with this text. As is apparent from the foregoing general description and the specific embodiments, while forms of the embodiments have been illustrated and described, various modifications may be made without departing from the spirit and scope of the present disclosure. Accordingly, it is not intended that the present disclosure be limited thereby. Likewise, the term “comprising” is considered synonymous with the term “including.” Likewise whenever a composition, an element, a group of elements, or a method is preceded with the transitional phrase “comprising,” it is understood that we also contemplate the same composition, method, or group of elements with transitional phrases “consisting essentially of,” “consisting of,” “selected from the group of consisting of,” or “Is” preceding the recitation of the composition, element, elements, or method, and vice versa, such as the terms “comprising,” “consisting essentially of,” “consisting of’ also include the product of the combinations of elements listed after the term.

[0133] In the foregoing, reference is made to embodiments of the disclosure. However, it should be understood that the disclosure is not limited to specific described embodiments. Instead, any combination of the following features and elements, whether related to different embodiments or not, is contemplated to implement and practice the disclosure. Furthermore, although embodiments of the disclosure may achieve advantages over other possible solutions and / or over the prior art, whether or not a particular advantage is achieved by a given embodiment is not limiting of the disclosure. Thus, the foregoing aspects, features, embodiments and advantages aremerely illustrative and are not considered elements or limitations of the appended claims except where explicitly recited in a claim(s). Likewise, reference to “the disclosure” shall not be construed as a generalization of any inventive subject matter disclosed herein and shall not be considered to be an element or limitation of the appended claims except where explicitly recited in a claim(s).

[0134] For purposes of this present disclosure, and unless otherwise specified, all numerical values within the detailed description and the claims herein are modified by “about” or “approximately” the indicated value, and consider experimental error and variations that would be expected by a person having ordinary skill in the art. For the sake of brevity, only certain ranges are explicitly disclosed herein. However, ranges from any lower limit may be combined with any upper limit to recite a range not explicitly recited, as well as, ranges from any lower limit may be combined with any other lower limit to recite a range not explicitly recited, in the same way, ranges from any upper limit may be combined with any other upper limit to recite a range not explicitly recited. For example, the recitation of the numerical range 1 to 5 includes the subranges 1 to 4, 1.5 to 4.5, 1 to 2, among other subranges. As another example, the recitation of the numerical ranges 1 to 5, such as 2 to 4, includes the subranges 1 to 4 and 2 to 5, among other subranges. Additionally, within a range includes every point or individual value between its end points even though not explicitly recited. For example, the recitation of the numerical range 1 to 5 includes the numbers 1, 1.5, 2, 2.75, 3, 3.80, 4, 5, among other numbers. Thus, every point or individual value may serve as its own lower or upper limit combined with any other point or individual value or any other lower or upper limit, to recite a range not explicitly recited.

[0135] As used herein, the indefinite article “a” or “an” shall mean “at least one” unless specified to the contrary or the context clearly indicates otherwise. For example, embodiments comprising “a layer” include embodiments comprising one, two, or more layers, unless specified to the contrary or the context clearly indicates only one layer is included.

[0136] While the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.

Claims

ClaimsWhat is claimed is:

1. A composite, comprising: a thermoplastic polymer; and a coal -based material.

2. The composite of claim 1, wherein the thermoplastic polymer comprises a thermoplastic polymer formed from polymerization of olefin-containing monomers.

3. The composite of claim 1, wherein the thermoplastic polymer comprises low density polyethylene, polypropylene, acrylonitrile butadiene styrene (ABS), nylon, polyvinyl chloride, or combinations thereof.

4. The composite of claim 1, wherein the thermoplastic polymer comprises low density polyethylene, polypropylene, or combinations thereof.

5. The composite of claim 1, wherein the composite comprises: from about 20 wt% to about 70 wt% of the coal -based material based on a total amount of the thermoplastic polymer and the coal -based material in the composite, the total amount of the thermoplastic polymer and the coal-based material in the composite not to exceed 100 wt%.

6. The composite of claim 1, wherein the composite comprises: from about 40 wt% to about 60 wt% of the coal -based material based on a total amount of the thermoplastic polymer and the coal -based material in the composite, the total amount of the thermoplastic polymer and the coal-based material in the composite not to exceed 100 wt%; and from about 60 wt% to about 40 wt% of the thermoplastic polymer based on the total amount of the thermoplastic polymer and the coal-based material in the composite.

7. The composite of claim 1, wherein the coal -based material comprises coal char, coal powder, or combinations thereof.

8. The composite of claim 1, wherein the composite comprises from about 20 to about 40 parts of the coal -based material to 100 parts of the thermoplastic polymer.

9. The composite of claim 1, wherein the coal -based material comprises pyrolyzed coal, flash pyrolyzed coal, or combinations thereof.

10. The composite of claim 1, wherein the coal -based material comprises a subbituminous coal -based material.

11. The composite of claim 1, wherein the composite is free of added compatibilizer.

12. The composite of claim 1, wherein the composite further comprises from greater than 0 wt% to about 0.1 wt% or less of compatibilizer.

13. The composite of claim 1, wherein the composite is free of added flame retardant.

14. The composite of claim 1, wherein the composite has: a density that is from about 0.945 kg / L to about 1.03 kg / L; an elongation at break that is greater than 10%; a Shore D hardness that is from 50 to 54; a Young’s modulus that is from about 50 MPa to about 100 MPa; or combinations thereof.

15. An article of manufacture, comprising the composite of claim 1.

16. A container, comprising the composite of claim 1.

17. An automotive part, comprising the composite of claim 1.

18. A method of forming a composite, the method comprising: processing a mixture comprising a thermoplastic polymer and a coal-based material to form a composite.

19. The method of claim 18, wherein: the thermoplastic polymer comprises low density polyethylene; the coal-based material comprises coal char, coal powder, or combinations thereof; or combinations thereof.

20. The method of claim 19, wherein, when the coal -based material comprises the coal char, the coal char comprises pyrolyzed coal, flash pyrolyzed coal, or combinations thereof.