PHAs fiber reinforced composite material as well as preparation method and application thereof

Abstract

The invention provides a PHAs fiber reinforced composite material and a preparation method and application thereof, raw materials of the PHAs fiber reinforced composite material comprise a PHAs matrix material and PHAs fibers, and the melting point difference between the PHAs matrix material and the PHAs fibers is not lower than 30 DEG C. According to the composite material disclosed by the invention, the fibers and the matrix are PHAs materials, so that the fibers and the matrix can be completely compatible, and the processes of adding a dispersing agent and a coupling agent, surface treatment and the like are not needed. Besides, a double-screw mixing mill is adopted for processing, the base material part is made of low-melting-point PHA and can be fully melted in the mixing process, the fiber part is made of high-melting-point PHA, the fiber form is kept in the mixing process, the real fiber reinforcing effect is finally achieved, and meanwhile the problem that fibers are difficult to strip after being recycled is solved.

Description

Technical Field

[0001] This invention relates to the field of composite material technology, and in particular to a PHAs fiber-reinforced composite material, its preparation method, and its application. Background Technology

[0002] Since the advent of synthetic plastics, plastic products have developed rapidly. However, since plastics are mainly derived from non-renewable fossil fuels and plastic waste is often disposed of through incineration and landfill, they pose a significant threat to the environment.

[0003] With the depletion of petroleum resources and the enormous pressure brought about by environmental pollution, bio-based resins synthesized from biomass raw materials have attracted much attention. For example, biodegradable polymer materials such as polylactic acid (PLA), polyhydroxyalkanoates (PHAs), and polybutylene terephthalate have been commercially produced. However, these polymer materials generally have the disadvantages of poor stability and high cost, making it difficult to popularize them in daily life.

[0004] To further improve the overall performance of the aforementioned biodegradable polymer materials, some existing technologies have adopted technical solutions that reinforce biodegradable polyester materials with glass fiber, carbon fiber, inorganic fillers, and natural plant fibers, for example: CN105968756B discloses a method for preparing polylactic acid-fiber composite materials. Modified microcrystalline cellulose is formed by enzymatic treatment of tobacco stems and tobacco dust. This modified microcrystalline cellulose is then mixed with polylactic acid, macroporous konjac glucomannan hydrogel, modified microcrystalline cellulose, filler, plasticizer, crosslinking agent, nucleating agent, coupling agent, compatibilizer, lubricant, and surfactant. The mixture is then extruded in an extruder and granulated.

[0005] In similar schemes, the different surface energies of the fiber and the matrix material lead to incompatibility between the fiber and the matrix material, resulting in material defects and affecting mechanical strength.

[0006] CN106626535B discloses a high fiber volume content PHBV monopolymer composite material, which is prepared by the following method: (1) processing core-sheath PHBV fibers into fiber assemblies; (2) stacking 1 to 1000 layers of core-sheath PHBV fiber assemblies together; (3) hot-pressing the core-sheath PHBV fiber assemblies into PHBV monopolymer composite material under certain pressure and temperature on a hot press.

[0007] Although the reinforcing phase and matrix of the aforementioned PHBV monopolymer composite are both PHBV, giving it good interfacial compatibility, the hot-pressing process only controls pressure and temperature. By lowering the hot-pressing temperature, the PHBV fibers melt to form a whole on the outside, while the core remains solid. This material has at least the following problems: 1. There is no shearing and mixing inside the material, resulting in a very limited composite structure, i.e., a fiber-stacking structure. 2. The formation of the composite sheet is equivalent to welding each fiber boundary together. Due to the low controlled temperature, the fusion between fibers is only in the skin layer, which is very weak. Consequently, the overall strength of the composite sheet will not be improved; instead, defects will appear due to poor fiber boundary fusion, reducing strength. 3. Hot pressing is difficult to industrialize.

[0008] Therefore, effective improvement solutions are still needed to address the various shortcomings of existing composite materials. This invention proposes a solution for fiber-reinforced integrated composite materials, which solves both the problem of poor interfacial compatibility of fiber reinforcement and the difficulty of fiber stripping during recycling. Summary of the Invention

[0009] The primary objective of this invention is to provide a fully marine-degradable PHAs fiber-reinforced composite material.

[0010] The PHAs fiber-reinforced composite material provided by the present invention includes PHAs matrix material and PHAs fibers as raw materials, wherein the melting point difference between the PHAs matrix material and the PHAs fibers is not less than 30°C.

[0011] The PHAs fiber-reinforced composite material provided by this invention uses PHAs materials for both the matrix and the fiber. Therefore, the fiber and the matrix are completely compatible, eliminating the need for dispersants, coupling agents, or surface treatment processes.

[0012] This invention uses PHAs fibers with a melting point higher than the selected PHAs matrix, so they can be melt-processed into fiber-reinforced composite materials using a traditional twin-screw mixer, while ensuring good compatibility between the fibers and the matrix.

[0013] The PHAs fibers used in this invention have the characteristics of high crystallinity, high strength and high melting point. Their melting point is preferably between 180 and 190°C. Below the melting point, they will maintain a highly oriented fiber morphology and will not melt.

[0014] The PHA matrix material used in this invention preferably has a melting point between 130 and 150°C, and / or a processing and molding temperature between 150 and 160°C. This type of matrix material has the advantages of low melting point, low processing temperature, and high thermal stability.

[0015] Preferably, the melting point of the PHAs matrix material is lower than that of the PHAs fibers, and the difference in melting points is 30~60℃, more preferably 35~50℃. This difference in melting point temperature ensures that the PHAs fibers do not melt during the melting and processing of the PHAs matrix material, while still maintaining fiber reinforcement.

[0016] Preferably, the raw materials do not contain dispersants or coupling agents.

[0017] The PHAs fiber-reinforced composite material provided by the present invention preferably has a PHAs matrix material to PHAs fiber ratio of 1 / 99 to 99 / 1, particularly 30 / 70 to 90 / 10; and / or, the mass percentage of PHAs fiber in the raw material is 1% to 30%.

[0018] Within the above dosage range, PHAs fibers can achieve ideal dispersion in PHAs matrix materials, thereby further ensuring the reinforcing effect of PHAs fibers.

[0019] Preferably, the PHAs fibers are short fibers of 1 to 50 mm, especially short fibers of 5 to 20 mm, so as to effectively ensure that the PHAs fibers are fully mixed with other components in the raw materials (such as PHAs matrix materials, nucleating agents, heat stabilizers, etc.), which is more conducive to maintaining the fiber morphology during the mixing process.

[0020] The PHAs fiber-reinforced composite material provided by the present invention is selected from one or more of PHB, P3HB4HB, PHBHHx, PHBV, P3HB4HB3HV and P3HB4HB5HV (the "several" mentioned in the present invention refers to a combination of two or more, the same below).

[0021] Depending on the specific implementation requirements, PHAs can be one type, or a combination of two or more types.

[0022] Preferably, the molar content of 3HV in PHBV is any value from 1% to 80%, such as 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 15%, 20%, 25%, 30%, 40%, 50%, 60%, 70%, or 80%.

[0023] Preferably, the molar content of 4HB in P3HB4HB is any value from 1% to 80%, such as 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 15%, 20%, 25%, 30%, 40%, 50%, 60%, 70%, or 80%.

[0024] Preferably, the molar content of HHx in PHBHHx is any value from 1% to 80%, such as 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 15%, 20%, 25%, 30%, 40%, 50%, 60%, 70%, or 80%.

[0025] Preferably, the molar content of 4HB or 3HV in P3HB4HB3HV is any value from 1% to 80%, for example, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 15%, 20%, 25%, 30%, 40%, 50%, 60%, 70%, or 80%.

[0026] Preferably, the molar content of 4HB or 5HV in P3HB4HB5HV is any value from 1% to 80%, for example, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 15%, 20%, 25%, 30%, 40%, 50%, 60%, 70%, or 80%.

[0027] In some embodiments provided by the present invention, the PHAs fiber is selected from one or more of PHB, P3HB4HB, PHBHHx, and PHBV, including but not limited to; the PHAs matrix material is selected from one or more of PHB, P3HB4HB, PHBHHx, PHBV, P3HB4HB3HV, and P3HB4HB5HV, including but not limited to.

[0028] In some preferred embodiments provided by the present invention, the combination of PHAs matrix material and PHAs fibers includes PHBHHx+PHB, P3HB4HB+PHB, P3HB4HB3HV+PHB, P3HB4HB5HV+PHB, or PHBHHx+PHBV, P3HB4HB+PHBV, P3HB4HB+P3HB4HB3HV, P3HB4HB+P3HB4HB5HV. The above combinations are particularly beneficial for ensuring the mechanical properties of PHAs fiber reinforced composite materials.

[0029] In some embodiments provided by the present invention, the raw materials of the PHAs fiber reinforced composite material, by weight, include: 1-99 parts of PHAs matrix material, 99-1 parts of PHAs fiber, 1-5 parts of nucleating agent, 0.1-2 parts of heat stabilizer, 0.1-2 parts of antioxidant, 0-5 parts of chain extender and 0-5 parts of plasticizer.

[0030] Preferably, the PHAs matrix material is 30-90 parts, more preferably 70-90 parts.

[0031] Preferably, the PHAs fiber is 1 to 50 parts, more preferably 1 to 30 parts.

[0032] In the composition of the PHA fiber described in this invention, the proportion of PHA is higher than 20%, preferably 50% to 100%, and more preferably 85% to 100%. The components other than PHA are inorganic fillers, nucleating agents, heat stabilizers, and melting point enhancing components. The melting point enhancing components can be selected from 0 or 1 of PGA, PLA, or PLGA in biodegradable polyesters.

[0033] In the above-mentioned formulation provided by this invention, the nucleating agent is selected from inorganic materials such as talc, magnesium silicate, bentonite, calcined kaolin, calcium carbonate, silicon dioxide, alum, titanium dioxide, calcium oxide, magnesium oxide, carbon black, and mica; dibenzyl sorbitol and its derivatives, aromatic phosphate salts; sodium succinate, sodium glutarate, sodium hexanoate, sodium 4-methylvalerate, adipic acid, aluminum adipic acid, aluminum tert-butylbenzoate, aluminum benzoate, potassium benzoate, lithium benzoate, and cinnamic acid. Sodium, sodium β-naphthoate and other carboxylic acid metal salts; 2,2′-methylenebis(4,6-tert-butylphenol), phosphine aluminum salt (NA-21) and other organophosphates; or one or more of sorbitol benzylidene derivatives, preferably talc, calcium carbonate, silica, dibenzylidene sorbitol, 2,2′-methylenebis(4,6-tert-butylphenol), phosphine aluminum salt (NA-21). These nucleating agents help improve the crystallinity, strength and thermal stability of fibers.

[0034] The nucleating agent of the present invention is preferably used in the raw materials in an amount of 1 to 5 parts, more preferably 1 to 4 parts, and even better in an amount of 1 to 3 parts.

[0035] In the above-mentioned formulation provided by the present invention, the heat stabilizer is selected from one or a combination of two of calcium stearate, zinc stearate, calcium laurate, magnesium laurate, zinc 2-ethylhexanoate, and magnesium 2-ethylhexanoate. Such heat stabilizers help prevent PHA thermal degradation.

[0036] The heat stabilizer described in this invention is preferably used in the raw materials at a dosage of 0.1 to 3 parts, more preferably 0.2 to 2 parts, and even better at 0.5 to 2 parts.

[0037] In the formulation provided by the present invention, the antioxidant is selected from one or more of phosphites, hindered phenols, and thioether compounds; preferably hindered phenols, such heat stabilizers help prevent the thermal degradation of PHA.

[0038] The antioxidant described in this invention is preferably used in the raw materials at a dosage of 0.1 to 3 parts, more preferably 0.1 to 2 parts, and even better at 0.5 to 2 parts.

[0039] In the formulation provided by this invention, the chain extender is selected from one or a combination of two of glycidyl methacrylate (GMA), oligomeric epoxy chain extenders, ethanolamine, tetrabutyl titanate, BASF ADR4400, BASF ADR4300, Vertellus E60P, trimethylolpropane, and EK-145; preferably BASF ADR4400, as such chain extenders help improve the compatibility of the mixture.

[0040] The chain extender described in this invention is preferably used in the raw material at a dosage of 0 to 5 parts, more preferably 0.5 to 4 parts, and even better at 0.5 to 3 parts.

[0041] In the above-mentioned formulation provided by the present invention, the plasticizer is selected from one or more of epoxidized soybean oil, triethyl citrate, tributyl citrate, and acetylated tributyl citrate; preferably triethyl citrate, such plasticizers help to increase the flexibility of the matrix material.

[0042] The amount of the plasticizer described in this invention in the raw material is preferably 0 to 5 parts, more preferably 0 to 4 parts, and even better 0 to 2 parts.

[0043] Using the above technical solution, the tensile strength of the PHA fiber-reinforced composite material provided by the present invention can be increased by up to 50% compared with pure PHA material.

[0044] The PHAs fiber-reinforced composite material provided by this invention may also include a lubricant as a raw material. The lubricant is selected from one or more of fatty acid salts and fatty amides.

[0045] The PHAs fiber-reinforced composite material provided by this invention may also include fiber filler materials as raw materials. The fiber filler materials are selected from one or more of cellulose, hemicellulose, lignin, coconut fiber, nano-montmorillonite, nano-calcium carbonate, nano-titanium boride, nano-titanium carbide, talc, titanium dioxide, bentonite, magnesium silicate, kaolin, and boron nitride.

[0046] The present invention does not impose any particular limitation on the source of each raw material in the above formula; any commercially available product in the art is acceptable.

[0047] The second objective of this invention is to provide a method for preparing the above-mentioned PHAs fiber-reinforced composite material.

[0048] The preparation method of the PHAs fiber-reinforced composite material of the present invention specifically involves: mixing the raw materials evenly and then co-extruding them in a twin-screw extruder.

[0049] This invention uses a twin-screw mixer for processing, which can effectively ensure that the matrix and fiber are completely mixed. The matrix material is made of low-melting-point PHA, which can be fully melted during the mixing process; the fiber material is made of high-melting-point PHA, which maintains the fiber shape during the mixing process, thereby ultimately achieving a true fiber reinforcement effect.

[0050] When the preparation method provided by the present invention is processed using a twin-screw mixer, the screw temperature is preferably controlled at 130~150℃, the die pressure at 1.5~4.0MPa, and the conveyor belt speed at 4~15rpm, preferably 5~12rpm, and more preferably 7~10rpm.

[0051] Preferably, during the above processing, the air cooling temperature is controlled at 40~60℃.

[0052] Preferably, the preparation method provided by the present invention further includes the step of obtaining PHA short fibers by melt spinning, specifically including: spinning PHA powder through a twin-screw melt spinning machine, wherein the spinning temperature is 165~170℃; the extrusion rate is 120~200m / min; and the draw ratio is 6~12.

[0053] More preferably, the number of holes in the die head of the twin-screw melt spinning machine is 12.

[0054] In some embodiments provided by the present invention, the raw material is spun under the above conditions, the spun material is cooled by a water bath and stretched, the stretch ratio is 6~12, the water temperature is controlled at 4°C, and PHA long fibers are obtained; after the obtained long fibers are dried, they are placed for 18~32 (preferably 24 hours) and cut into short fibers of 1~50mm (preferably 5~20mm).

[0055] The third objective of this invention is to provide the application of the above-mentioned PHAs fiber-reinforced composite materials in disposable environmentally friendly materials, fiber-reinforced composite materials, and packaging materials.

[0056] The bio-based biodegradable composite material provided by this invention uses PHAs as both the fiber and matrix. Therefore, this composite material possesses unique properties such as no need for separation, easy recycling, and complete biodegradability by marine organisms. It is suitable for thermoforming processes such as injection molding and extrusion molding, effectively improving the mechanical strength and toughness of the products. Furthermore, the microstructure of the molded product is a fiber-reinforced composite material, with the matrix and fiber being the same material. The compatibility between the matrix and fiber is excellent, and unlike traditional glass fiber and carbon fiber composites, it does not require separation, filling, and reprocessing during recycling, demonstrating extremely strong application prospects. Attached Figure Description

[0057] To more clearly illustrate the technical solutions in this invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be described below.

[0058] Figure 1 This is a schematic diagram of the structure of the PHAs fiber-reinforced composite material of the present invention. Detailed Implementation

[0059] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this invention, not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0060] Example 1

[0061] This embodiment provides a PHAs fiber-reinforced composite material and its preparation method. Specifically, the formulation of the PHAs fiber-reinforced composite material is as follows: 70 parts PHBHHx matrix powder (from Kaneka Corporation), 22 parts PHAs fiber, 3 parts nucleating agent talc (from United Micro Powder 3000 mesh), 1 part heat stabilizer calcium stearate (from Fisher Chemical™ catalog number C136 from Thermo Fisher Scientific), 1 part antioxidant (from JYANOX-1010 from Beijing Jiyi), 2 parts chain extender (from JoncrylADR-4400 from BASF), and 1 part plasticizer tributyl citrate (from Sigma-Aldrich CAS No.: 77-94-1).

[0062] The PHA fiber formulation is as follows: 85 parts of PHB powder (from Beijing Microstructure Factory PB3000), 2 parts of nucleating agent talc powder (from United Micro Powder 3000 mesh), 2 parts of heat stabilizer calcium stearate (from Thermo Fisher's Fisher Chemical™ catalog number C136), 1 part of antioxidant (from Beijing Jiyi's JYANOX-1010), 10 parts of PLA (from NatureWorks® PLA polymer 6060D), and 0 parts of nano-montmorillonite (from United Micro Powder BT-001).

[0063] The method for preparing the above-mentioned PHAs fiber-reinforced composite material includes the following steps: 1. Fiber material granulation process

[0064] The PHA fiber formulation was added to a twin-screw mixer according to the solid ratio for extrusion granulation. Additives and granules were added via side feeding to ensure uniform mixing. The screw temperature was controlled at 160~170℃, the die pressure at 1.5~4.0MPa, the conveyor belt speed at 7.8rpm, and the air cooling temperature at 50±1℃.

[0065] 2. Fiber manufacturing process

[0066] PHA fibers were spun using a twin-screw melt spinning machine at a spinning temperature of 165-170℃. The die had 12 orifices, and the extrusion rate was 120-200 m / min. The spun fibers were cooled in a water bath and then stretched. The stretch ratio was 6-12, and the water temperature was 4℃, resulting in long PHA fibers.

[0067] After drying the obtained long fibers, let them stand for 24 hours and then cut them into short fibers of 1-50mm.

[0068] 3. Composite material processing technology

[0069] PHA short fibers are mixed evenly with PHA powder (PHBHHx), nucleating agents, and other raw materials, and then co-extruded in a twin-screw extruder. The screw temperature is controlled at 130~150℃, the die pressure at 1.5~4.0MPa, the conveyor belt speed at 7.8rpm, and the air cooling temperature at 50℃. The resulting granules or strips can be further used for injection molding, compression molding, extrusion, and other molding processes.

[0070] Example 2

[0071] 80 parts of PHBHHx matrix powder (from Kaneka Corporation), 12 parts of PHAs fiber, 3 parts of nucleating agent talc powder (from United Micro Powder 3000 mesh), 1 part of heat stabilizer calcium stearate (from Fisher Chemical™ catalog number C136 from Thermo Fisher Scientific), 1 part of antioxidant (from JYANOX-1010 from Beijing Jiyi), 2 parts of chain extender (from JoncrylADR-4400 from BASF), and 1 part of plasticizer tributyl citrate (from Sigma-Aldrich CAS No.: 77-94-1).

[0072] The PHA fiber formulation is as follows: 90 parts of PHB powder (from Beijing Microstructure Factory PB3000), 2 parts of nucleating agent talc powder (from United Micro Powder 3000 mesh), 2 parts of heat stabilizer calcium stearate (from Thermo Fisher's Fisher Chemical™ catalog number C136), 1 part of antioxidant (from Beijing Jiyi's JYANOX-1010), and 5 parts of nano montmorillonite (from United Micro Powder BT-001).

[0073] The method for preparing the above-mentioned PHAs fiber-reinforced composite material includes the following steps: 1. Fiber material granulation process

[0074] The PHA fiber formulation was added to a twin-screw mixer according to the solid ratio for extrusion granulation. Additives and granules were added via side feeding to ensure uniform mixing. The screw temperature was controlled at 160~170℃, the die pressure at 1.5~4.0MPa, the conveyor belt speed at 7.8rpm, and the air cooling temperature at 50℃±1.

[0075] 2. Fiber manufacturing process

[0076] PHA fibers were spun using a twin-screw melt spinning machine at a spinning temperature of 165-170℃. The die had 12 orifices, and the extrusion rate was 120-200 m / min. The spun fibers were cooled in a water bath and then stretched. The stretch ratio was 6-12, and the water temperature was 4℃, resulting in long PHA fibers.

[0077] After drying the obtained long fibers, let them stand for 24 hours and then cut them into short fibers of 1-50mm.

[0078] 3. Composite material processing technology

[0079] PHA short fibers are mixed evenly with PHA powder (PHBHHx), nucleating agents, and other raw materials, and then co-extruded in a twin-screw extruder. The screw temperature is controlled at 130~150℃, the die pressure at 1.5~4.0MPa, the conveyor belt speed at 7.8rpm, and the air cooling temperature at 50℃. The resulting granules or strips can be further used for injection molding, compression molding, extrusion, and other molding processes.

[0080] Comparative Example 1

[0081] This comparative example provides a PHA composite material, the specific formulation and preparation method of which are as follows: 72 parts of PHBHHx matrix powder (from Kaneka Corporation), 20 parts of PLA (NatureWorks® PLApolymer 6060D) fiber, 3 parts of nucleating agent talc (from United Micro Powder 3000 mesh), 1 part of heat stabilizer calcium stearate (from Fisher Chemical™ catalog number C136 of Thermo Fisher Scientific), 1 part of antioxidant (from JYANOX-1010 of Beijing Jiyi), 2 parts of chain extender (from Joncryl ADR-4400 of BASF), and 1 part of plasticizer tributyl citrate (from Sigma-Aldrich CAS No.: 77-94-1).

[0082] Composite material processing technology: PLA short fibers are mixed evenly with PHA powder (PHBHHx), nucleating agent talc, and other raw materials, and then fed into a twin-screw extruder for co-extrusion. The screw temperature is controlled at 130~150℃, the die pressure at 1.5~4.0MPa, the conveyor belt speed at 7.8rpm, and the air cooling temperature at 50℃.

[0083] The specific categories of functional components selected in Examples 1-2 and Comparative Example 1 are shown in Table 1.

[0084] Table 1

[0085] Experimental Example 1

[0086] The composite materials obtained in Examples 1-2 and Comparative Example 1 were subjected to performance testing. The testing methods included: Tensile strength: The test method refers to standard GB / T 1040.2-2006.

[0087] Elongation at break: The test method is in accordance with standard GB / T 1040.2-2006.

[0088] Impact strength: The test method refers to standard GB / T 1043.2-2018.

[0089] Heat distortion temperature: The test method refers to standard GB / T 1634.2-2019.

[0090] The test results are shown in Table 2 below.

[0091] Table 2

[0092] The test results in Table 2 show that in Comparative Example 1, the PLA fiber had poor compatibility with the PHBHHx matrix, resulting in the PLA fiber not reinforcing the matrix; instead, defects caused by interphase gaps led to a decrease in strength. In Examples 1 and 2, the PHA fiber and the matrix were of the same type of material, therefore there were no interphase defects, allowing the fiber to fully reinforce the matrix. It was also found that adding different reinforcing components (MMT and PLA) to the fiber had significantly different reinforcing effects. The reinforcing effect of the composite material can be adjusted by modifying the PHA fiber formulation.

[0093] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A PHAs fiber-reinforced composite material, wherein the raw materials include a PHAs matrix material, characterized in that, The raw materials also include PHAs fibers, and the melting point difference between the PHAs matrix material and the PHAs fibers is not less than 30°C, preferably 30~60°C, and more preferably 35~50°C.

2. The PHAs fiber-reinforced composite material according to claim 1, characterized in that, The melting point of the PHAs fiber is 180-190°C; and / or the melting point of the PHAs matrix material is 130-150°C.

3. The PHAs fiber-reinforced composite material according to claim 1 or 2, characterized in that, In the raw materials, the ratio of the PHAs matrix material to the PHAs fibers is 1 / 99 to 99 / 1; preferably, the PHAs fibers are short fibers of 1 to 50 mm.

4. The PHAs fiber-reinforced composite material according to claim 1 or 2, characterized in that, PHAs are selected from one or more combinations of PHB, P3HB4HB, PHBHHx, PHBV, P3HB4HB3HV and P3HB4HB5HV. Preferably, the molar content of 3HV in PHBV is 1-80%; the molar content of 4HB in P3HB4HB is 1-80%; the molar content of HHx in PHBHHx is 1-80%; the molar content of 4HB or 3HV in P3HB4HB3HV is 1-80%; and the molar content of 4HB or 5HV in P3HB4HB5HV is 1-80%.

5. A PHAs fiber-reinforced composite material, characterized in that, By weight, the raw materials include: 1-99 parts of PHAs matrix material, 99-1 parts of PHAs fiber, 1-5 parts of nucleating agent, 0.1-2 parts of heat stabilizer, 0.1-2 parts of antioxidant, 0-5 parts of chain extender and 0-5 parts of plasticizer.

6. The PHAs fiber-reinforced composite material according to claim 5, characterized in that, The nucleating agent is selected from one or more of talc, calcium carbonate, silica, dibenzyl sorbitol, 2,2′-methylenebis(4,6-tert-butylphenol), and phosphonium aluminum salt (NA-21); and / or, the heat stabilizer is selected from one or more of calcium stearate, zinc stearate, calcium laurate, magnesium laurate, zinc 2-ethylhexanoate, and magnesium 2-ethylhexanoate; and / or, the antioxidant is selected from one or more of phosphites, hindered phenols, and thioether compounds; and / or, the chain extender is selected from one or more of glycidyl methacrylate (GMA), oligomeric epoxy chain extenders, ethanolamine, tetrabutyl titanate, BASF ADR4400, BASF ADR4300, Vertellus E60P, trimethylolpropane, and EK-145; and / or, the plasticizer is selected from one or more of epoxidized soybean oil, triethyl citrate, tributyl citrate, and acetylated tributyl citrate.

7. The PHAs fiber-reinforced composite material according to claim 5 or 6, characterized in that, The raw materials also include lubricants; preferably, the lubricants are selected from one or more of fatty acid salts and fatty amides.

8. A method for preparing the PHAs fiber-reinforced composite material according to any one of claims 1-7, characterized in that, The raw materials are mixed evenly and then fed into a twin-screw extruder for co-extrusion.

9. The method for preparing the PHAs fiber-reinforced composite material according to claim 8, characterized in that, The screw temperature is 130~150℃, the die pressure is 1.5~4.0MPa, and the conveyor belt speed is 4~15rpm.

10. The application of the PHAs fiber-reinforced composite material according to any one of claims 1-7 in disposable environmentally friendly materials, fiber-reinforced composite materials, and packaging materials.

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