Biocomposites based on biodegradable polymers

Abstract

The present invention provides a composition for use in the manufacture of a biodegradable composite, and a biodegradable composite comprising a polybutylene adipate terephthalate (PBAT) component; hemp powder; and optionally one or more compatibilizers and / or 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, copolymers of glycidyl methacrylate and / or copolymers of acrylic acid. The present invention also relates to a method for preparing said composite.

Description

[Technical Field]

[0001] The present invention relates to the field of biodegradable polymeric materials. In particular, the present invention relates to polymer-based biocomposites and methods for their preparation. [Background technology]

[0002] Plastics have played a vital role in the development of human society over the last century.[1] The majority of plastic materials are primarily derived from fossil fuels.[2] These petroleum-derived plastics are strong, tough, rigid, durable, relatively lightweight, inexpensive, long-lasting, and thermally and chemically stable, depending on the type of polymer used in each application.[3] This makes them suitable for disposable applications such as packaging, construction, transportation, and consumer goods. However, the release of plastics after use has not been managed and controlled, resulting in a significant environmental pollution burden.[4]

[0003] Recent efforts towards sustainable approaches to plastics management have led to increased interest in utilizing biodegradable and / or biobased polymers to manufacture disposable consumer goods, including polylactic acid (PLA), polyhydroxyalkanoate (PHA), polybutylene adipate terephthalate (PBAT), polybutylene succinate (PBS), polycaprolactone (PCL), etc. [5].

[0004] Among biodegradable polymers, polybutylene adipate terephthalate (PBAT), an aliphatic-aromatic copolyester, is one of the most attractive biodegradable polymers touted as a potential replacement for single-use plastics in consumer goods and packaging applications. In addition to its biodegradability, PBAT possesses mechanical properties comparable to those of various commodity plastics, making it attractive for food packaging and consumer goods applications. However, its cost is approximately three times higher than low-density polyethylene, its low hardness / stiffness, and its relatively low service temperature limit prevent its widespread use in cost-competitive commodity plastics.[6]

[0005] The use of bio-sourced materials as fillers in the development of biocomposites is an effective approach to improve modulus and reduce the cost of the final product. [7] Various bio-based materials, such as lignin [8], chitin [9], silk powder

[10] , natural fibers [11, 12], coffee grounds

[13] , apple (lingo) cellulosic fillers

[14] , microalgae biomass

[15] , distiller-dried soluble grains

[16] , corn residue

[17] , and other biomass [18, 19], have been investigated by many researchers in PBAT-based biocomposites. The poor interfacial adhesion between a typically hydrophobic polymer matrix, such as PBAT, and hydrophilic bio-sourced fiber-based fillers remains one of the unresolved challenges in biocomposites.

[0006] Therefore, there is a need for cost-competitive biodegradable materials with desired mechanical and / or thermomechanical properties that can be prepared from biodegradable polymers and sustainable, low-cost biodegradable fillers to replace conventional plastics.

[0007] This background information is provided for the purpose of making known information believed by the applicant to be of possible relevance to the present invention. No admission is necessarily intended, nor should it be construed, that any of the preceding information constitutes prior art against the present invention. [Prior art documents] [Non-patent literature]

[0008] [Non-Patent Document 1] Geyer, R., JR Jambeck, and KL Law, Production, use, and fate of all plastics ever made. Science Advances, 2017. 3(7): p. e1700782. [Non-patent document 2] Millet, H., et al., The Nature of Plastics and Their Societal Usage, in Plastics and the Environment. 2019, The Royal Society of Chemistry. p. 1-20. [Non-patent document 3] The future of plastic. Nature Communications, 2018. 9(1): p. 2157. [Non-patent document 4] Jambeck, JR, et al., Plastic waste inputs from land into the ocean. Science, 2015. 347(6223): p. 768-771. [Non-patent document 5] Di Bartolo, A., G. Infurna, and NT Dintcheva, A Review of Bioplastics and Their Adoption in the Circular Economy. Polymers, 2021. 13(8): p. 1229. [Non-patent document 6] Mekonnen, T., et al., Progress in bio-based plastics and plasticizing modifications. Journal of Materials Chemistry A, 2013. 1(43): p. 13379-13398. [Non-Patent Document 7] Nakayama, D., et al., Biodegradable Composites Developed from PBAT / PLA Binary Blends and Silk Powder: Compatibilization and Performance Evaluation. ACS Omega, 2018. 3(10): p. 12412-12421. [Non-patent document 8] Mohanty, A.K., et al., Composites from renewable and sustainable resources: Challenges and innovations. Science, 2018. 362(6414): p. 536-542.

Non-Patent Document 9

Non-Patent Document 10

Non-Patent Document 11

Non-Patent Document 12

Non-Patent Document 13

Non-Patent Document 14

Non-Patent Document 15

Non-Patent Document 16

[0009] The object of the present invention is to provide a biodegradable biocomposite based on PBAT. [Means for solving the problem]

[0010] According to one aspect of the present invention, there is provided a composition for use in making a biodegradable composite, the composition comprising: a) about 30 to 99.5 wt. % of a polybutylene adipate terephthalate (PBAT) component; b) about 0.5 to 50 wt. % of hemp residue; and c) optionally, about 0.1 to 50 wt. % 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, copolymers of glycidyl methacrylate and / or copolymers of acrylic acid, and / or one or more compatibilizers selected from maleic anhydride, pyromellitic anhydride, acrylic acid; polyacrylic acid, and methylene diphenyl diisocyanate.

[0011] According to one aspect of the present invention, there is provided a biodegradable composite comprising or consisting of: a) about 30-99.5 wt. % of a polybutylene adipate terephthalate (PBAT) component; b) about 0.5-50 wt. % of hemp residue; and c) optionally, about 0.1-50 wt. % 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, copolymers of glycidyl methacrylate and / or copolymers of acrylic acid), and / or one or more compatibilizers selected from maleic anhydride, pyromellitic anhydride, acrylic acid; polyacrylic acid, and methylene diphenyl diisocyanate, wherein the mixture is heated.

[0012] According to another aspect of the present invention, there is provided a method of preparing a biocomposite as described herein, the method comprising mixing a PBAT component with hemp residue, and optionally a compatibilizer, and extruding the mixture at an extrusion temperature sufficient to melt at least the PBAT.

[0013] According to another aspect of the present invention, there is provided a method for preparing a biocomposite as described herein, the method comprising: a) preparing a grafted PBAT by combining PBAT with one or more compatibilizers and a free radical initiator to form a reaction mixture and melt processing the reaction mixture to form the grafted PBAT; and b) mixing the grafted PBAT prepared in step a) with a PBAT component, hemp residue, and an optional plasticizer and / or filler, and extruding the mixture at an extrusion temperature sufficient to melt at least the PBAT. [Brief explanation of the drawings]

[0014] The invention will now be described by way of exemplary embodiments with reference to the accompanying drawings, in which: [Figure 1] FIG. 1A is a morphological analysis of the hemp residue, FIG. 1B is the FTIR spectrum of the hemp residue, FIG. 1C is the thermogravimetric data of the hemp residue, and FIG. 1D is the differential weight loss data of the hemp residue. [Figure 2] Figure 2 shows the FTIR spectra of PBAT before (bottom) and after (top) MA grafting. [Figure 3] Figures 3A-3B show DSC thermograms of PBAT and its biocomposite at various hemp residue content levels and in the presence of MA. Figure 3A shows the heating curve, and Figure 3B shows the cooling curve. [Figure 4] 4A-4D show the results of TGA studies of biocomposites according to embodiments of the present invention, where Figure 4A shows the percent weight loss versus temperature for a prepared sample without mPBAT, and Figure 4B shows the percent weight loss versus temperature for a prepared sample with mPBAT. [Figure 5] Figures 5A-5D show the results of tensile testing of exemplary biocomposites according to embodiments of the present invention: Figure 5A shows the mechanical strength and elongation at break; Figure 5B shows the tensile modulus and toughness; Figure 5C shows the corresponding stress-strain curves of the developed biocomposites; and Figure 5D shows the effect of HP on the heat deflection temperature of the biocomposites. [Figure 6] 6A-6D show the effect of temperature on the load-bearing capacity of the specimens, with FIGS. 6A and 6B showing the storage modulus of biocomposites of embodiments of the invention without and with mPBAT, and FIGS. 6C and 6D showing the tan delta of biocomposites without and with mPBAT. [Figure 7] 7A-7C show the rheological properties of PBAT and its biocomposites with and without the presence of MA, according to an embodiment of the present invention: Figure 7A shows the complex viscosity, Figure 7B shows the storage modulus, and Figure 7C shows the loss modulus. [Figure 8] Figure 8A is an SEM micrograph of hemp powder, Figure 8B shows the fracture surface of pure PBAT, Figure 8C shows the fracture surface of a PBAT-10HP biocomposite according to an embodiment of the present invention, and Figure 8D shows the fracture surface of a PBAT-40HP biocomposite according to an embodiment of the present invention. [Figure 9] 9A to 9D are SEM micrographs of the fracture surface of PBAT-40HP at different magnifications: (a) 500x and (b) 1000x, and (c) 500x and (d) 1000x, respectively, and of the fracture surface of PBAT-40HP-M. [Figure 10] Figure 10 shows the gel content in the developed biocomposites due to the presence of mPBAT. [Figure 11] FIG. 11 shows representative cutlery and flexible sheets prepared by compression molding with the PBAT-40HP-M biocomposite according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0015] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0016] As used herein, the term "about" refers to a ±10% variation from the nominal value. It is to be understood that such a variation is always included in any given value provided herein, whether or not specifically stated.

[0017] As used herein, the term "hemp residue" (HR) refers to crushed hemp stalks in which the hemp hard and / or fibrous materials have been ground and / or sliced ​​into micron-sized particles. The residue may be in the form of a powder or dust.

[0018] As used herein, the term "biodegradable" refers to materials that deteriorate or break down when exposed to sunlight or ultraviolet light, water or moisture, microorganisms such as bacteria and fungi, enzymes, or wind erosion. In some cases, attack by rodents, vermin, or insects can also be considered a form of biodegradation or environmental degradation.

[0019] As used herein, the term "thermoplastic starch" (TP starch) refers to starch blended with a suitable plasticizer.

[0020] The present invention relates to novel compositions for making biodegradable biocomposites and to biodegradable biocomposites formed from these compositions.

[0021] The biocomposites of the present invention exhibit improved tensile modulus, tensile strength, and heat deflection while maintaining sufficient toughness of the biocomposite, providing overall attractive material properties and compostability compared to pure PBAT, making them attractive for a wide range of disposable consumer goods such as fast food items, cosmetic containers, and food containers.

[0022] In one aspect, the present invention provides a composition for use in making a biodegradable biocomposite, the composition comprising: a) about 30-99.5 wt. % polybutylene adipate terephthalate (PBAT) component; and about 0.5-50 wt. % hemp residue. The composition also optionally comprises about 0.1-50 wt. % of one or more compatibilizers selected from maleic anhydride, glycidyl methacrylate, pyromellitic anhydride, acrylic acid; polyacrylic acid; methylene diphenyl diisocyanate; poly(glycidyl methacrylate, copolymers of glycidyl methacrylate, and copolymers of acrylic acid), and / or about 0.1-50 wt. % 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, copolymers of glycidyl methacrylate, and copolymers of acrylic acid).

[0023] In another aspect, the present invention provides a biodegradable biocomposite made from a blend of about 30-99.5 wt% polybutylene adipate terephthalate (PBAT) component and about 0.5-50 wt% hemp residue. The mixture optionally comprises about 0.1 to 50% by weight of one or more compatibilizers selected from maleic anhydride, glycidyl methacrylate, pyromellitic anhydride, acrylic acid; polyacrylic acid, methylene diphenyl diisocyanate, poly(glycidyl methacrylate, copolymers of glycidyl methacrylate, and copolymers of acrylic acid), and / or PBAT grafted with about 0.1 to 50% by weight of one or more compatibilizers selected from maleic anhydride, glycidyl methacrylate, pyromellitic anhydride, acrylic acid, polyacrylic acid, methylene diphenyl diisocyanate; poly(glycidyl methacrylate, copolymers of glycidyl methacrylate, and / or copolymers of acrylic acid, and the mixture is heated.

[0024] The PBAT component of the present invention may be a polybutylene adipate terephthalate (PBAT) polymer, a mixture of PBAT, starch and a plasticizer, or a blend of PBAT and thermoplastic starch.

[0025] In some embodiments, the PBAT component is polybutylene adipate terephthalate (PBAT).

[0026] In some embodiments, the PBAT component is a mixture of PBAT, starch, and plasticizer, wherein the PBAT is about 50-65% by weight of the composition, the starch is about 15-35% by weight of the composition, and the plasticizer is about 10-15% by weight of the composition.

[0027] In some embodiments, the PBAT component is a PBAT-thermoplastic starch blend, with the PBAT being about 50-65% by weight of the composition and the thermoplastic starch being about 30-40% by weight of the composition.

[0028] In some embodiments, the compositions and / or biocomposites of the present invention comprise one or more compatibilizers selected from maleic anhydride, pyromellitic anhydride, acrylic acid; polyacrylic acid, methylene diphenyl diisocyanate, and copolymers of acrylic acid.

[0029] In some embodiments, the compositions and / or biocomposites of the present invention comprise one or more compatibilizers selected from maleic anhydride, glycidyl methacrylate, pyromellitic anhydride, and methylene diphenyl diisocyanate.

[0030] 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.

[0031] In some embodiments, the compositions and / or biocomposites of the present invention further comprise about 20-40% plasticizer.

[0032] 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 Examples of suitable polyols include trihexyl citrate (BTHC), trimethyl citrate (TMC), alkyl sulfonic acid phenyl esters (ASE), lignosulfonates, beeswax, oils, sugars, sorbitol, and polyols such as 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, fumarates, or combinations thereof.

[0033] 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, fumarates, or combinations thereof.

[0034] The hemp residue of the present invention can be prepared by milling and / or crushing hemp stalks to obtain micron-sized particles. In some embodiments, the hemp residue comprises crushed hemp hurd and bast fibers. In some embodiments, the hemp residue is primarily composed of hemp cores and remaining bast fibers. In some embodiments, the hemp residue is composed of hemp hurds. In some embodiments, the residue is in the form of a powder.

[0035] In some embodiments, prior to milling or grinding, the hemp stalks are washed with an approximately 2-10% aqueous solution of sodium hydroxide (1 part stalk per 10 parts solution by weight) and then dried.

[0036] In some embodiments, the hemp residue comprises particles having a length of about 75 to 150 μm, a width of about 15 to 40 μm, and an aspect ratio of about 3.5 to 5. In some embodiments, the hemp powder has a particle size of about 1.0 to 2.0 g / cm. 3 It has a density of

[0037] In some embodiments, the hemp residue comprises about 60-75% cellulose, 5-15% hemicellulose, and about 10-25% lignin.

[0038] In some embodiments, the hemp residue is pre-treated to remove tetrahydrocannabinol (THC) and cannabidiol (CBD).

[0039] In some embodiments, the compositions and / or biocomposites of the present invention comprise PBAT as the PBAT component, hemp residue and a compatibilizer or PBAT grafted with one or more compatibilizers.

[0040] In some embodiments, compositions and / or biocomposites of the invention comprise 30-99% PBAT, about 5 to about 40% hemp residue, and about 0.1-20% PBAT grafted with one or more compatibilizers, which in some embodiments is maleic anhydride.

[0041] In some embodiments, the composition approximately 50–70 wt.% PBAT; about 25-30% by weight starch; about 10-15% by weight of glycerol; about 0.2 to 0.7 weight percent stearic acid; and About 0.2% to about 0.7% by weight of hemp residue Includes.

[0042] The starch can be any plant starch (root and / or grain starch) such as potato starch, sweet potato starch, corn starch, bracken starch, wheat starch, cassava starch, sago starch, rice starch, tapioca starch, soybean starch, arrowroot starch, lotus starch, buckwheat starch or any mixture thereof.

[0043] In some embodiments, the starch is raw (ie, in its natural state), that is, the starch has not been modified by chemical or other means.

[0044] In some embodiments, the composition and / or biocomposite comprises about 1-3% by weight of a processing agent, such as glycerol monostearate and / or stearic acid.

[0045] In some embodiments, the composition and / or biocomposite comprises an inorganic filler (e.g., talc, clay, wollastonite, montmorillonite, or alkali or alkaline earth metal carbonates, bicarbonates, oxides, or sulfates, etc.).

[0046] In some embodiments, the composition further comprises about 0.5-5% colorant, such as a mineral and / or dye, hi some embodiments, the composition comprises about 1% colorant.

[0047] In another aspect, the present invention provides a method for preparing the biodegradable biocomposite of the present invention. The method includes blending a PBAT component with hemp residue and, optionally, a compatibilizer or compatibilizer-grafted PBAT described herein, and extruding the mixture at an extrusion temperature sufficient to melt at least the PBAT. In some embodiments, the mixture is extruded through a screw extruder at a screw speed of about 80-120 rpm and a processing temperature of about 150°C-220°C. In some embodiments, the mixture is extruded through a screw extruder at a screw speed of about 380-450 rpm and a processing temperature of about 130°C-200°C.

[0048] In some embodiments, the PBAT ingredients and hemp powder are dried to remove residual moisture before processing. The drying step can be accomplished in a conventional oven at approximately 60-100°C, or by common industrial drying methods, such as using a desiccant wheel dryer or Munters desiccant wheel (overnight at approximately 40-60°C).

[0049] In some embodiments, the resulting biocomposite is air-cooled and pelletized.

[0050] In some embodiments, the compatibilizer-grafted PBAT can be prepared by combining PBAT with one or more compatibilizers and a free radical initiator to form a reaction mixture, and melt processing the reaction mixture to form the grafted PBAT.

[0051] 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 compatibilizers, followed by the addition of a free radical initiator prior to melt processing.

[0052] In some embodiments, melt processing is accomplished at a temperature of about 150°C to 220°C.

[0053] In some embodiments, melt processing comprises melt extrusion, which in some embodiments is carried out via a screw extruder at a screw speed of about 80-120 rpm and a feed rate of about 300-750 g / h.

[0054] In some embodiments, the resulting biocomposite is dried to remove unreacted compatibilizer.

[0055] In some embodiments, the biocomposites of the present invention comprising PBAT grafted with one or more compatibilizers are a) preparing the grafted PBAT by first combining PBAT with one or more compatibilizers and a free radical initiator 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 the PBAT component, hemp residue, and optional plasticizers and / or fillers, and extruding the mixture at a processing temperature sufficient to melt the PBAT. It can be prepared by

[0056] In one aspect, the present invention provides a biocomposite produced by the methods described herein.

[0057] In order to better understand the invention described herein, the following examples are described with reference to the accompanying drawings, in which: It will be understood that these examples are intended to illustrate exemplary embodiments of the invention and are not intended to limit the scope of the invention in any manner. [Example]

[0058] Example 1: Preparation of Hemp Powder (HP) To produce HP, the bast fibers are removed from the stems, and the remaining woody core (also called the hurd) and residual fiber are processed in a pulverizer to produce a fine powder of hemp hurd and residual fiber containing micron-sized particles. The resulting HP contained less than 1% tetrahydrocannabinol (THC).

[0059] Lignin and cellulose content determination of HP The lignin content of hemp flour (HP) was measured using the procedure adopted by Zhu et al.

[20] . Briefly, 1 g of dried HP was treated with ethanol at 30 °C for 4 h to remove pectin and wax, which was found to be approximately 2–5%. The ethanol-washed hemp flour was then subjected to 72% aqueous sulfuric acid cooking at 20 °C for 2 h with continuous stirring. After acid cooking, the solution was diluted with enough distilled water to a total acid content of 3% and boiled for 4 h. The cooked mass was then cooled to room temperature, filtered, and subsequently washed with distilled water. The insoluble fraction, lignin (L, in grams), was dried in a conventional oven at 80 °C for 24 h and weighed. The remaining soluble fraction was considered the cellulosic fraction (cellulose and hemicellulose) of the HP.

[0060] α-Cellulose was dissolved in NaOH (2.5 mol L -1 ) and Na2SO3 (0.4 mol L -1 The cellulose was separated from HP by dissolving the lignin and hemicellulose in an aqueous solution of 2.5 mol / L. A predetermined amount of HP was suspended in the basic solution and refluxed at 100 °C for 12 hours. After dissolving the lignin and hemicellulose, the undissolved material was collected and washed several times with distilled water to remove residual chemicals. The collected solid was then immersed in a boiling hydrogen peroxide solution (2.5 mol / L). -1 The white solid was collected, washed thoroughly with cold distilled water, dried at 80°C overnight, and weighed.

[0061] Using the microscope image shown in Figure 1A, the particle size of the hemp powder prepared as described above was found to be approximately 120 μm in length and 27 μm in width with an aspect ratio of approximately 4.4. The density of the HP was measured using back-calculation after the reactive extrusion process to be 1.27 gm / cm. 3 It was.

[0062] The components such as cellulose, hemicellulose, and lignin in hemp flour (HP) were determined using cooking and acid hydrolysis techniques and are listed in Table 1.

[0063] [Table 1]

[0064] The presence of 68-70% cellulose confirms the abundance of hydroxyl functional groups on the surface of HP. The presence of functional groups on HP was confirmed using FTIR, and a typical spectrum is shown in Figure 1B. Peaks corresponding to the carboxyl functional groups (C=O) and CO of pectin and wax are present on HP, at 1744 cm and 1744 cm, respectively. -1 and 1249 cm -1 The stretching vibration of the hydroxyl group of cellulose, and the symmetric and asymmetric stretching vibration of the CH group were observed as broad peaks around 3380 cm. -1 , 2903cm -1 , 2937cm -1 It was shown as 1312cm -1 ~1465cm -1 The peaks between 881 cm and 882 cm correspond to cellulose and hemicellulose. -1 ~1168cm -1 The spectra in the range of 1000 nm correspond to the backbone structures of cellulose and hemicellulose. Overall, these spectra confirm the presence of pectin, wax, lignin, cellulose, and hemicellulose in the HP used in this study.

[0065] Example 2: Preparation of MA-grafted PBAT We used an industrially viable melt extrusion technique to produce MA-grafted PBAT (mPBAT). First, PBAT pellets were mixed with 5 wt% maleic anhydride (MA) and held in a hot air oven at 80 °C for approximately 30 min to dissolve the MA and create a thin crust coating on the PBAT pellets. The mixture was cooled and mixed with 1 wt% dicumyl peroxide (DCP) as a reaction initiator, followed by stirring before melt processing. Reactive extrusion was carried out in a twin-screw extruder (Thermo Scientific, Haake Process 11, USA) with eight temperature zones, with a die-to-feed temperature profile of 130 / 135 / 140 / 150 / 150 / 140 / 135 / 130 °C. The screw (440 mm long, L / D 40:1) speed was maintained at 60 rpm (to ensure sufficient reaction time) and the feed rate was approximately 500 g / h. The resulting mPBAT was then pelletized, weighed, and dried in a vacuum oven at 80° C. under reduced pressure (100 mbar) for 24 hours to remove unreacted MA from the sample.

[0066] Quantification of grafted MA onto PBAT The grafted MA onto 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 a few drops of hydrochloric acid (HCl) to hydrolyze all the anhydride groups present in mPBAT.

[0067] Hydrolysis of the anhydride groups results in the formation of carboxylic acid functional groups, which are detected as an acid number as per ASTM D1386. The hydrolyzed solution was titrated with 0.1 M potassium hydroxide (KOH) in alcohol in the presence of phenolphthalein as an indicator. The percentage of MA was determined using equation (1).

[0068] where M, V, and W are the molar concentration, the end volume of the KOH solution used (in liters), and the weight of the sample used (in chloroform), respectively. The MA grafting on mPBAT (calculated based on the average of five end volumes) is shown as a percentage.

[0069] Example 3: Preparation of a biocomposite comprising PBAT, hemp residue, and optionally PBAT grafted with a compatibilizer PBAT and hemp flour (HP) were weighed and dried overnight at 80°C in a conventional oven to remove residual moisture before processing. PBAT was then blended with various HP and mPBAT contents, as shown in Table 2, and melt-processed in a twin-screw extruder at a screw speed of 100 rpm at a processing temperature of 180°C (full range). The resulting biocomposites were air-cooled and pelletized. The resulting pellets were used to prepare specimens for tensile testing, dynamic mechanical analysis (DMA), and rheological measurements using a piston injection molding system (HAAKE® MiniJet Pro, Thermo Fisher Scientific, USA) with cylinder, mold, and pressure settings of 190°C, 30°C, and 700 bar, respectively. The specimens were stored in Ziploc® bags for further use. Further addition of HP beyond 40 wt% was not continued in this study because it would torque the extruder due to viscosity increase.

[0070] [Table 2]

[0071] Quantification of gel content Gel formation in the developed biocomposites can be a qualitative indicator of the reaction between the anhydride of mPBAT and the -OH moiety of HP. Therefore, gel content was quantified by Soxhlet extraction, which involved successive washings of approximately 0.5 g of each sample in chloroform at 80 °C. The sample was then wrapped in 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 this process was repeated a total of 16–20 cycles. This ensured that PBAT and unreacted mPBAT were completely removed from the sample while limiting the leakage of gel and HP. The filter paper was weighed before and after extraction, and the gel content value was calculated as a percentage of the initial weight. Soxhlet extraction did not remove any existing unreacted hemp powder from the sample (due to the absence of solvent coloration). The percentage gel content was calculated using the following equation (2):

[0072] TIFF0007825699000004.tif1393Where i , W f , and C are the initial sample weight, the sample weight after Soxhlet extraction, and the HP content of the sample.

[0073] Characterization Fourier transform infrared spectroscopy Fourier transform infrared spectroscopy (FTIR) scans were collected using a Thermo Scientific Nicollet 6700. 50 mg of each sample was dissolved in 10 mL of chloroform. Once dissolved, a small amount (less than 1 mL) of the solution was dropped onto a pure KBr salt pellet. FTIR analysis was then performed with 64 scans in a nitrogen (N2) background.

[0074] Mechanical and thermomechanical analysis The tensile properties of the specimens were measured using a Shimadzu (Japan) Universal Tensile Machine AGS-X series with a 500 N load cell at a crosshead speed of 5 mm / min and a gauge length of 25 mm. Tensile properties of at least five specimens were tested, and the average measurements and standard deviations were reported. Specimens were injection molded into a dumbbell shape with average dimensions of 50 mm (gauge length) × 3.3 mm (thickness) × 3.2 mm (width) according to ASTM D638 Type V.

[0075] Thermomechanical data were recorded using a DMA instrument (Q800, TA Instruments, USA). For this, samples were tested in strain mode using a dual cantilever orientation at a temperature range of -80°C to 90°C, a heating rate of 3°C / min, a frequency of 1 Hz, and a temperature range of 100°C to 120°C. Rectangular specimens (50 mm (length, L) × 11.9 mm (width, W) × 3 mm (thickness, T)) were injection molded and subjected to DMA testing according to ASTM D648-07. The heat deflection temperature (HDT) of the specimens was also evaluated using DMA. The force (F), strain (ε), and deflection (D) required for the measurement were calculated according to the equations introduced elsewhere

[21] as follows:

[0076] TIFF0007825699000005.tif39124Here, σ is considered to be the stress of 0.455 MPa applied to the specimen.

[0077] Scanning Electron Microscopy (SEM) The fracture surface morphology of the developed biocomposites was investigated using a Zeiss Leo 1530 field emission scanning electron microscope (FE-SEM). The prepared fractured samples were lightly coated with gold nanoparticles, and high-resolution images were obtained.

[0078] Differential scanning calorimetry (DSC) The thermal behavior of PBAT and its biocomposites was investigated using a differential scanning calorimeter (DSC) (TA Instruments Q2000, USA) with a typical heating-cooling-heating program. Approximately 5 mg of each sample was first cooled to -80°C, and then the sample was heated from -80°C to 160°C at a heating rate of 10°C / min. The sample was then cooled back to -80°C and finally heated again to 160°C at the same heating rate. The glass transition temperatures (T g ), melting temperature (T m ), and enthalpy of fusion (Δ Hm ) was used to investigate the change in the thermal behavior of PBAT after intimate mixing with various loading levels of HP. The crystallinity (X c ) was calculated from the ratio of the area under the second melting peak in the DSC thermogram to the melting enthalpy of 100% crystalline PBAT, as shown in equation (6) below.

[0079] TIFF0007825699000006.tif1588where ΔH m is the enthalpy of melting of the PBAT sample, ΔHm 100 is the enthalpy of fusion of 100% crystalline PBAT (i.e., 114 J / g

[22] ), w f is the weight fraction of hemp powder added.

[0080] Thermogravimetric analysis (TGA) All extruded samples were pelletized into approximately 2 mm pieces before characterization by TGA (2 Star System, Mettler Toledo, Switzerland). TGA scans were performed from 30 °C to 700 °C at a heating rate of 10 °C / min under a nitrogen (N2) atmosphere. Collected data were analyzed for peak and onset temperatures.

[0081] Rheology The melt rheological properties of pure PBAT and its biocomposites with and without mPBAT were investigated using a rheometer (Thermo Scientific, HAAKE MARS III, USA). The samples were heated to 180 °C in the linear viscoelastic (LVE) region with a parallel plate configuration. 35 mm diameter plates with a 1 mm gap between the plates were used for the study. A strain of 1% was applied, and the rheological properties of the PBAT biocomposites within the frequency range of 0.01–100 Hz were reported.

[0082] MA grafting onto PBAT The grafting of MA onto PBAT was confirmed using FTIR analysis, as shown in Figure 2. For PBAT, the peak at 2957 cm -1 , 2887cm -1 , and 1734 cm -1 The peaks at 1100 cm correspond to the stretching vibrations of symmetric and asymmetric CH groups and C=O groups, respectively. -1 ~1600cm -1 Other peaks around 3060 cm are attributed to the stretching vibrations of the PBAT backbone COC and the phenylene groups of the PBAT chain. -1 and 1954 cm -1 The appearance of new peaks at 1687 cm corresponds to the =CH stretching vibration in the anhydride and the asymmetric stretching of the C=C group occurring between the anhydride and the PBAT chain, respectively. -1 The new shoulder generated at is assigned to the carbonyl functional group of the low molecular weight PBAT resulting from β-scission of the chain. Overall, the radical-initiated MA grafting was successful. Furthermore, the degree of maleation based on titration studies was found to be 2.27% ± 0.28 using Eq. (1)

[23] .

[0083] Thermal behavior of PBAT / hemp powder biocomposites The DSC heating and cooling thermograms of PBAT / HP at various hemp powder contents are shown in Figure 3 (A and B). Data extracted from the DSC thermograms, namely the glass transition temperature (T g ), melting temperature (T m ), crystallization temperature (Tc ), and crystallinity (X c ) are shown in Table 3. g There was no significant shift (less than 1°C) in the T of PBAT containing mPBAT after homogenous mixing of 10-40 wt% hemp powder. g was shifted to higher temperatures in the mPBAT / HP biocomposite, indicating that the interaction between PBAT and HP was enhanced as a result of the bonding effect of MA grafting. The PBAT polymer chain motion was restricted by the strong interphase adhesive force with HP due to the presence of mPBAT, so T g rises.

[0084] PBAT's T m After homogenization of hemp powder, the temperature shifted to a higher temperature (increased by about 1-3°C), and the 10 wt% hemp-filled PBAT biocomposite showed a T m A similar trend was observed for the PBAT-HP / mPBAT biocomposite, with the largest increase in T at 10 wt% hemp powder. m The T of the PBAT-HP biocomposite was increased when compared to hemp / PBAT with and without the presence of mPBAT across the entire range of hemp powder loading. m was decreased in the presence of the mPBAT coupling agent, confirming the effective compatibilization of HP and PBAT.

[0085] The enthalpy of fusion and cooling of PBAT decreased with increasing hemp powder content, indicating that the presence of hemp powder prevented the crystal formation and melt crystallization of PBAT. Furthermore, the addition of hemp powder and MA reduced the PBAT content, which also reduced the energy required to melt the crystals, leading to a decrease in the T of the biocomposite. m This may be the reason for the decrease in the calculated crystallinity X c The X of PBAT decreases when HP is added to PBAT. c fell from 3.77% to 2.70% (see Table 3).

[0086] [Table 3]

[0087] As shown in Figure 3B, the T c was not significantly affected by the addition of HP up to 30 wt% (only about 1°C difference). When the HP content reached 40 wt%, T c As the amount of hemp powder added increased, T c The intensity of the peak decreased and the peak width broadened, which is consistent with the change in the crystallite size of PBAT when HP was intimately mixed. The crystallization process of 40 wt% HP-filled PBAT occurred at approximately 91 °C, compared with 87 °C for pure PBAT. This indicates that the presence of HP may induce heterogeneous nucleation growth and crystallization of PBAT.

[0088] Overall, the X of HP / PBAT with MA coupling agent c showed a decrease compared to the one without mPBAT. The bonding effect and effective interfacial adhesion between the matrix and hemp powder with the addition of mPBAT coupling agent caused a more severe interruption to the crystallization process and therefore the overall crystallinity

[24] . Therefore, the interphase of the composite was improved, and the addition of mPBAT improved the nucleation rate of PBAT and X. c has decreased.

[0089] Figures 4A and 4B show the TGA study of the biocomposite. The onset temperature of decomposition of HP (T on ) was found to be 281°C, much lower than the decomposition onset temperature of PBAT (~372°C). In the case of the biocomposite, the decomposition temperature of HP shifted to a higher temperature, where the production and leakage of HP decomposition products such as gases decreased, due to the encapsulation of HP by PBAT chains. This encapsulation was more pronounced in the case of biocomposites containing mPBAT. In contrast to pure PBAT as the matrix of the biocomposite, the homogeneous blending of mPBAT resulted in a T onAn increase of at least 10 °C was observed in the T. For biocomposites containing mPBAT, the lowest T on The char formation observed at the end of the biocomposite decomposition was also consistent with the HP loading level.

[0090] Mechanical and thermomechanical properties of biocomposites Figures 5A-5D show the results of tensile testing of exemplary biocomposites. The yield tensile strength (TS) and tensile modulus (TM) gradually increased from 7.9 MPa and 79.5 MPa for unfilled PBAT to 14.3 MPa and 505 MPa, respectively, after the addition of 40% HP. The increase in TS and TM indicated the strengthening effect of HP. Conversely, the elongation at break significantly decreased from 520% ​​(PBAT) to 6.8% (PBAT-40HP), indicating relatively weak interactions between HP and PBAT chains. With 10% mPBAT, TS improved to 24.4 MPa, a significant (209%) improvement accompanied by the expected decrease in TM. Ultimate tensile strength (UTS) also increased from 18.7 MPa to 24.4 MPa (a 31% improvement) (Table 3). This significant increase in TS indicates improved interfacial adhesion between HP and PBAT chains, attributed to the bonding effect of mPBAT. Compared to highly loaded PBAT, improved elongation at break was observed with the intimate blending of mPBAT. For example, for PBAT containing 30% HP, an improvement of 165% (Figure 5A) was observed after the addition of 10% mPBAT, and its toughness increased by 375% (Figure 5B).

[0091] Figures 6A–6D depict the effect of temperature on the load-bearing capacity of specimens, as assessed using DMA analysis. The incorporation of HP fillers demonstrated a significant increase in storage modulus across the investigated temperature range. At 25°C, unfilled PBAT exhibited a storage modulus of 205 MPa, while the 40HP biocomposite (PBAT-40HP) exhibited a storage modulus of 2034 MPa. In contrast, the incorporation of mPBAT (PBAT-40HP-M) reduced the storage modulus to 1652 MPa, which may be related to the plasticizing effect of mPBAT containing low molecular weight chains (Figures 6A and 6B). A similar phenomenon was observed at lower temperatures. Tan delta, an indicator of the glass transition of the polymer biocomposite, was found to be between -18°C and 22°C (Figures 6C and 6D). This is significantly different from the DSC data. This variation in glass transitions in DSC and DMA is a result of the different mechanisms used in the analysis.

[0092] In practical applications, heat deflection temperature (HDT) is a very important parameter that needs to be considered. The HDT data of the biocomposite are shown in Figure 5D. The restriction of PBAT chains due to the homogeneous mixing of HP significantly improved the HDT. For the pristine PBAT, the HDT was approximately 39°C, but it increased to 93°C with the addition of 40% HP. With the addition of mPBAT, the HDT slightly decreased to 90°C due to the plasticizing effect of the low molecular weight PBAT chains.

[0093] Rheological properties of PBAT biocomposites Figures 7A-7C depict the melt rheological properties of the developed PBAT biocomposites, namely, the complex viscosity, storage modulus, and loss modulus as a function of frequency sweep. The complex viscosity of PBAT was found to exhibit Newtonian behavior at low frequency sweeps. However, at higher frequencies, shear-thinning behavior gradually took over (Figure 7A). Similarly, for the storage modulus and loss modulus, PBAT did not exhibit frequency dependence in the low- to mid-frequency range, reflecting Newtonian behavior. The reinforcing effect of HP in PBAT is clearly evident in its rheological behavior, as the complex viscosity, storage modulus, and loss modulus of PBAT are lower than those of the PBAT-HP biocomposite. The complex viscosity, storage modulus, and loss modulus of PBAT increased with increasing HP loading levels (Figures 7A-C). As the HP content increased beyond 20 wt%, the complex viscosity of PBAT at low frequencies gradually changed to shear-thinning behavior. Increasing the complex viscosity also applies to improving the storage modulus and loss modulus.

[0094] The storage and loss moduli of pure PBAT exhibited a typical liquid-like melt deformation response. As the HP of the PBAT-HP biocomposite increased, the storage and loss moduli also shifted toward a plateau at lower frequencies (Figure 7B–C).

[0095] PBAT-10HP containing mPBAT showed improved complex viscosity, storage modulus, and loss modulus compared to PBAT-10HP. This indicates greater compatibility and interfacial interaction between the components, resulting in a higher complex viscosity. In addition to enhancing hemp powder-PBAT interactions, MA may induce mild cross-linking of PBAT chains. The hydroxyl and carbonyl groups of PBAT can be easily bonded using MA during reactive extrusion. Consequently, processing with mPBAT improved the complex viscosity, storage modulus, and loss modulus of PBAT. However, when the HP content exceeded 20 wt%, the complex viscosity of PBAT-HP was found to be higher than that of PBAT-HP-M. Similar trends were observed in both the storage modulus and loss modulus, indicating that the compatibilizing effect of mPBAT improved the chain mobility of PBAT and the dispersibility of hemp powder at high HP contents. The binding effect created flexibility, resulting in a decrease in complex viscosity. Using mPBAT to reduce the complex viscosity of PBAT biocomposites is promising because they are easy to process even with high hemp flour content.

[0096] Mechanisms involved in the improvement of interfacial adhesion between HP and PBAT By intimately incorporating mPBAT into the biocomposite using a reactive extrusion process, a chemical reaction occurs between the mPBAT and hemp powder, forming covalent bonds. The formation of these chemical bonds allows the HP particles to be encapsulated by PBAT chains, which can easily disperse and interact with the PBAT chains during the melt reactive extrusion process. This improved interfacial interaction significantly impacted the tensile strength, as well as the elongation at break and toughness, of the developed biocomposites with high loadings of hemp powder (20-40%).

[0097] The resulting improved interfacial adhesion between HP and PBAT was observed using SEM and is shown in Figures 8A-8D and 9A-9D. It can be seen that the hemp powder exhibited a wavy surface structure along with changes in particle size. The fracture surfaces of pure PBAT, PBAT-10HP, and PBAT-40HP biocomposites are shown in Figures 8B-D, respectively. PBAT-40HP exhibited poor particle dispersion with overlapping particles as a result of the high loading, while PBAT-10HP exhibited good particle distribution without substantial aggregation. A comparison of the SEM fracture surfaces of PBAT-HP with and without mPBAT is shown in Figures 9A-D at two different magnifications. The PBAT-HP biocomposite exhibited large interfacial voids, indicating poor particle-matrix interaction (Figures 9A-B). This indicates surface incompatibility and low interfacial adhesion between hemp powder and PBAT due to the large difference in surface polarity. The particle-matrix interface of the biocomposite was found to be significantly enhanced by the intimate incorporation of the mPBAT compatibilizer. The hemp powder was completely encapsulated and attached to the PBAT (Figures 9C-D). There were no noticeable voids at the particle-matrix interface, as can be seen when mPBAT was added to PBAT-HP. The enhanced interfacial interaction by the addition of mPBAT to PBAT-HP was also reflected in the tensile strength and elongation at break data discussed in the previous section. The reaction of MA with PBAT and its further reaction with HP resulted in the formation of a gel in the polymer system, suggesting successful crosslinking (Figure 10).

[0098] As discussed above, the incorporation of hemp powder improves the tensile strength and modulus of PBAT at higher loadings. However, at higher loading levels, the toughness and elongation at break of the resulting biocomposite decrease. Reactive extrusion of PBAT with hemp powder and its compatibilization enhances the tensile strength along with the toughness and elongation at break.

[0099] Representative cutlery and flexible films were prepared using PBAT-40HP-M samples to demonstrate the processability and applications of the biocomposites, as shown in Figure 11. Furthermore, a high loading of HP may also contribute to an increase in the biodegradation rate.

[0100] Example 4: Preparation of biocomposite containing PBAT, starch, plasticizer and hemp residue A mixture containing 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 flour was extruded using a STEER World OMEGA 20 twin-screw extruder using the following temperature profile: 25-130-150-155-165-170-175°C, a feed rate of about 15 lbs / hr, and a screw speed of 410 RPM.

[0101] Mechanical and thermomechanical analysis The tensile properties of the samples of the product of Example 4 were measured using a Shimadzu AGS-X series universal tensile machine equipped with a 500N load cell at a crosshead speed of 5mm / min and a gauge length of 25mm.

[0102] Test specimens were injection molded in a dumbbell shape per ASTM D638 Type V. The results, along with average values, are summarized in Table 4 below.

[0103] [Table 4]

[0104] The biocomposite prepared in Example 4 can be used in injection molding to form rigid containers and shapes.

[0105] While the present invention has been described with reference to certain specific embodiments, various modifications thereof will be apparent to those skilled in the art without departing from the spirit and scope of the invention. All such modifications apparent to those skilled in the art are intended to be included within the scope of the following claims. The initial disclosure of this specification encompasses at least the following aspects. [1] a) about 30 to 99.5 wt% polybutylene adipate terephthalate (PBAT) component; b) about 0.5 to 50% by weight of hemp residue; and c) optionally, about 0.1 to 50 wt. % 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, copolymers of glycidyl methacrylate and / or copolymers of acrylic acid), and / or one or more compatibilizers selected from maleic anhydride, pyromellitic anhydride, acrylic acid, polyacrylic acid, and methylene diphenyl diisocyanate; 1. A composition for use in making a biodegradable biocomposite, comprising: [2] The composition according to [1], wherein the PBAT component is polybutylene adipate terephthalate (PBAT), and the composition comprises about 0.1 to 50% of PBAT grafted with one or more of the compatibilizers. [3] The composition according to [2] above, further comprising 20 to 40% by weight of a plasticizer. [4] The composition according to [1], wherein the PBAT component is a mixture of PBAT, starch, and a plasticizer, and the PBAT is about 50 to 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. [5] The composition of [1], wherein the PBAT component is a PBAT-thermoplastic starch blend, the PBAT being about 50-65% by weight of the composition, and the thermoplastic starch being about 30-40% by weight of the composition. [6] The composition according to any one of [1] to [5], wherein the hemp residue comprises particles having a length of about 75 to 150 μm, a width of about 15 to 40 μm, and an aspect ratio of about 3.5 to 5. [7] The hemp residue is about 1.0 to 2.0 g / cm 3 The composition according to any one of the above [1] to [6], having a density of [8] The composition according to any one of [1] to [7], wherein the hemp residue contains approximately 60 to 75% cellulose, 5 to 15% hemicellulose, and approximately 10 to 25% lignin. [9] The composition according to any one of [1] to [8], wherein the hemp residue is treated to remove THC and CBD therefrom.

[10] The composition according to any one of [1] to [9] above, further comprising about 1 to 3% by weight of a processing agent such as glycerol monostearate and / or stearic acid.

[11] The composition according to any one of [1] to [9] above, further comprising an inorganic filler (such as talc, clay, wollastonite, montmorillonite, or an alkali metal or alkaline earth metal carbonate, bicarbonate, oxide, or sulfate).

[12] A biocomposite made of the composition according to any one of [1] to

[11] above.

[13] a) about 30 to 99.5 wt% polybutylene adipate terephthalate (PBAT) component; b) about 0.5 to 50% by weight of hemp residue; and c) optionally, 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, copolymers of glycidyl methacrylate and / or copolymers of acrylic acid); and / or one or more compatibilizers selected from maleic anhydride, pyromellitic anhydride, acrylic acid; polyacrylic acid, and methylene diphenyl diisocyanate; wherein the mixture is heated.

[14] The biocomposite according to

[13] , wherein the PBAT component is polybutylene adipate terephthalate (PBAT), and the biocomposite comprises 0.1 to 50 wt. % of the PBAT grafted with one or more of the compatibilizers.

[15] The biocomposite according to

[14] , further comprising 20 to 40 wt % of a plasticizer.

[16] The biocomposite of

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

[17] The biocomposite of

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

[18] The biocomposite according to any one of

[13] to

[17] , wherein the hemp residue comprises particles having a length of about 75 to 150 μm, a width of about 15 to 40 μm, and an aspect ratio of about 3.5 to 5.

[19] The hemp residue is about 0.2 to 2.0 g / cm 3 The biocomposite according to any one of

[13] to

[17] above, having a density of

[20] The biocomposite according to any one of

[13] to

[19] , wherein the hemp residue contains approximately 60 to 75% cellulose, 5 to 15% hemicellulose, and approximately 10 to 25% lignin.

[21] The biocomposite according to any one of

[13] to

[20] , wherein the hemp residue has been pretreated to remove THC and CBD.

[22] The biocomposite according to any one of

[13] to

[21] above, further comprising about 1 to 3 wt. % of a processing agent such as glycerol monostearate and / or stearic acid.

[23] The biocomposite according to any one of

[13] to

[22] above, further comprising an inorganic filler (e.g., talc, clay, wollastonite, montmorillonite, or an alkali metal or alkaline earth metal carbonate, bicarbonate, oxide, or sulfate).

[24] a) mixing a PBAT component with hemp residue and, optionally, a compatibilizer; and b) extruding the mixture at an extrusion temperature at least sufficient to melt the PBAT. A method for preparing the biocomposite according to any one of

[13] to

[23] above, comprising:

[25] The method according to

[24] , wherein the mixture is extruded through a screw extruder at a screw speed of about 80 to 120 rpm and a processing temperature of about 150 to 220°C.

[26] The method according to

[24] , wherein the mixture is extruded through a screw extruder at a screw speed of about 380 to 450 rpm and a processing temperature of about 130 to 200°C.

[27] The method according to

[24] or

[25] , wherein the composite is air-cooled and pelletized.

[28] A method for preparing a biocomposite according to any one of

[13] to

[23] above, wherein the composite comprises PBAT grafted with one or more compatibilizers, and the method a) preparing a grafted PBAT by combining PBAT, one or more compatibilizers, and a free radical initiator to form a reaction mixture, and melt processing the reaction mixture to form a compatibilizer-grafted PBAT; and b) mixing the compatibilizer-grafted PBAT prepared in step a) with the PBAT component, hemp residue, and optional plasticizers and / or fillers, and extruding the mixture at an extrusion temperature sufficient to melt the PBAT; A method comprising:

Claims

1. a) 30 to 80 wt. % of a polybutylene adipate terephthalate (PBAT)-containing component, wherein the PBAT-containing component is polybutylene adipate terephthalate (PBAT); b) 0.5 to 50% by weight of hemp residue containing crushed hemp stalks in which hemp hurds and / or fibers have been crushed and / or sliced ​​into microparticles; and c) 0.1 to 50% by weight PBAT grafted with one or more compatibilizers selected from maleic anhydride, glycidyl methacrylate, pyromellitic anhydride, acrylic acid, polyacrylic acid, methylene diphenyl diisocyanate, polyglycidyl methacrylate, copolymers of glycidyl methacrylate and / or copolymers of acrylic acid.

1. A composition for use in making a biodegradable biocomposite, comprising:

2. The composition described in claim 1, further comprising a plasticizer.

3. a) 30 to 99.5 wt. % polybutylene adipate terephthalate (PBAT)-containing component; b) 0.5 to 50% by weight of hemp residue containing crushed hemp stalks in which the hemp hurds and / or fibers have been crushed and / or sliced ​​into micro-sized particles; and c) optionally 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, polyglycidyl methacrylate, copolymers of glycidyl methacrylate and / or copolymers of acrylic acid, and / or one or more compatibilizers selected from maleic anhydride, pyromellitic anhydride, acrylic acid, polyacrylic acid, and methylene diphenyl diisocyanate; Including, the PBAT-containing component comprises PBAT, starch, and a plasticizer, wherein the PBAT is 50-65% by weight of the composition, the starch is 15-35% by weight of the composition, and the plasticizer is 10-15% by weight of the composition; or A composition for use in preparing a biodegradable biocomposite, wherein the PBAT-containing component comprises PBAT and thermoplastic starch, the PBAT being 50-65% by weight of the composition, and the thermoplastic starch being 30-40% by weight of the composition.

4. 4. The composition of claim 1 or 3, wherein the hemp residue comprises particles having a length of 75 to 150 μm, a width of 15 to 40 μm, and an aspect ratio of 3.5 to 5.

5. The hemp residue is 1.0 to 2.0 g / cm ３ 4. The composition of claim 1 or 3, having a density of

6. 4. The composition of claim 1 or 3, wherein the hemp residue comprises 60-75% cellulose, 5-15% hemicellulose, and 10-25% lignin.

7. 4. The composition of claim 1 or 3, wherein the hemp residue is treated to remove tetrahydrocannabinol (THC) and cannabidiol (CBD) therefrom.

8. The composition of claim 1 or 3, further comprising an inorganic filler.

9. A biocomposite made from the composition of claim 1 or 3.

10. a) 30 to 80 wt. % of a polybutylene adipate terephthalate (PBAT)-containing component, wherein the PBAT-containing component is polybutylene adipate terephthalate (PBAT); b) 0.5 to 50% by weight of hemp residue containing crushed hemp stalks in which the hemp hurds and / or fibers have been crushed and / or sliced ​​into micro-sized particles; and c) PBAT grafted with 0.1 to 50% by weight of one or more compatibilizers selected from maleic anhydride, glycidyl methacrylate, pyromellitic anhydride, acrylic acid, polyacrylic acid, methylene diphenyl diisocyanate; polyglycidyl methacrylate, copolymers of glycidyl methacrylate and / or copolymers of acrylic acid.

1. A biocomposite comprising a mixture of:

11. The biocomposite of claim 10, further comprising a plasticizer.

12. a) 30 to 99.5 wt. % polybutylene adipate terephthalate (PBAT)-containing component; b) 0.5 to 50% by weight of hemp residue containing crushed hemp stalks in which the hemp hurds and / or fibers have been crushed and / or sliced ​​into micro-sized particles; and c) PBAT optionally grafted with 0.1 to 50% by weight of one or more compatibilizers selected from maleic anhydride, glycidyl methacrylate, pyromellitic anhydride, acrylic acid, polyacrylic acid, methylene diphenyl diisocyanate; polyglycidyl methacrylate, copolymers of glycidyl methacrylate and / or copolymers of acrylic acid, and / or one or more compatibilizers selected from maleic anhydride, pyromellitic anhydride, acrylic acid; polyacrylic acid, and methylene diphenyl diisocyanate; a mixture of the PBAT-containing component comprises PBAT, starch, and a plasticizer, wherein the PBAT is 50-65% by weight of the composition, the starch is 15-35% by weight of the composition, and the plasticizer is 10-15% by weight of the composition; or A biocomposite wherein the PBAT-containing component comprises PBAT and thermoplastic starch, the PBAT being 50-65% by weight of the composition and the thermoplastic starch being 30-40% by weight of the composition, and the mixture is heated.

13. 13. The biocomposite of claim 10 or 12, wherein the hemp residue comprises particles having a length of 75-150 μm, a width of 15-40 μm, and an aspect ratio of 3.5-5.

14. The hemp residue is 0.2 to 2.0 g / cm ３ 13. The biocomposite of claim 10 or 12, having a density of

15. 13. The biocomposite of claim 10 or 12, wherein the hemp residue comprises 60-75% cellulose, 5-15% hemicellulose, and 10-25% lignin.

16. 13. The biocomposite of claim 10 or 12, wherein the hemp residue has been pretreated to remove tetrahydrocannabinol (THC) and cannabidiol (CBD).

17. 13. The biocomposite of claim 10 or 12, further comprising an inorganic filler.

18. a) mixing a PBAT-containing component with hemp residue and, optionally, a compatibilizer; and b) extruding the mixture at an extrusion temperature sufficient to melt the PBAT.

13. A method for preparing the biocomposite of claim 12, comprising:

19. 19. The method of claim 18, wherein the mixture is extruded through a screw extruder at a screw speed of 80 to 120 rpm and a processing temperature of 150 to 220°C.

20. 19. The method of claim 18, wherein the mixture is extruded through a screw extruder at a screw speed of 380 to 450 rpm and a processing temperature of 130 to 200°C.

21. 21. The method of claim 19 or 20, wherein the composite is air-cooled and pelletized.

22. 13. A method for preparing a biocomposite according to claim 12, wherein the composite comprises PBAT grafted with one or more compatibilizers, the method comprising: a) preparing a grafted PBTA by combining PBAT, one or more compatibilizers, and a free radical initiator to form a reaction mixture, and melt processing the reaction mixture to form a compatibilizer-grafted PBTA; and b) mixing the compatibilizer-grafted PBAT prepared in step a) with a PBAT-containing component, hemp residue, and optional plasticizers and / or fillers, and extruding the mixture at an extrusion temperature sufficient to melt at least the PBAT; A method comprising:

23. 11. A method for preparing a biocomposite according to claim 10, wherein the composite comprises PBAT grafted with one or more compatibilizers, the method comprising: a) preparing a grafted PBTA by combining PBAT, one or more compatibilizers, and a free radical initiator to form a reaction mixture, and melt processing the reaction mixture to form a compatibilizer-grafted PBTA; and b) mixing the compatibilizer-grafted PBAT prepared in step a) with a PBAT-containing component, hemp residue, and optional plasticizers and / or fillers, and extruding the mixture at an extrusion temperature sufficient to melt at least the PBAT; A method comprising:

24. 24. The method of claim 23, wherein the mixture is extruded through a screw extruder at a screw speed of 80 to 120 rpm and a processing temperature of 150 to 220°C.

25. 24. The method of claim 23, wherein the mixture is extruded through a screw extruder at a screw speed of 380 to 450 rpm and a processing temperature of 130 to 200°C.

26. 26. The method of claim 24 or 25, wherein the composite is air-cooled and pelletized.

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