Polyhydroxyalkanoate composition and preparation method therefor and use thereof

Abstract

The present application provides a polyhydroxyalkanoate (PHA) composition and a preparation method therefor and a use thereof. The PHA composition comprises a PHA terpolymer, wherein the PHA terpolymer is P3HB4HB3HV, P3HB4HB5HV, or a combination of P3HB4HB3HV and P3HB4HB5HV. The PHA composition containing the specific PHA terpolymer provided by the present invention can achieve many excellent properties including marine degradability, with a small amount of auxiliary agent or even without an auxiliary agent.

Description

A polyhydroxyalkanoate composition and its preparation method and application

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese patent application No. 202311783873X, filed on December 22, 2023, entitled “A polyhydroxyalkanoate composition, its preparation method and application”; claims priority to Chinese patent application No. 2023117838725, filed on December 22, 2023, entitled “A polyhydroxyalkanoate composition, its preparation method and application”; and claims priority to Chinese patent application No. 2024101136873, filed on January 26, 2024, entitled “A polyhydroxyalkanoate composition, its preparation method and application”, all of which are incorporated herein by reference. Technical Field

[0003] The present application relates to the field of biodegradable polymer materials, and in particular to a polyhydroxyalkanoate composition, a preparation method thereof, and an application thereof. Background Art

[0004] As white pollution becomes increasingly serious, people are increasingly demanding environmentally friendly and biodegradable materials. In particular, those who care about ocean health and low-carbon sustainability are in greater need of bio-based materials that are marine degradable and compostable at home.

[0005] Currently, PLA, PBS, and PBAT no longer meet these requirements. The main options currently available include PCL, PGA, starch, cellulose, and PHA. However, PCL's melting point is too low, limiting its practical applications. PGA has strong rigidity but poor toughness, but ages and degrades rapidly, resulting in a short shelf life. The performance of materials like starch and cellulose is not particularly impressive, making them difficult to use as primary components. Therefore, PHA has become the most promising biodegradable material. However, most PHA types still face challenges in processing and application, including high melting points, narrow thermal processing windows, and poor performance.

[0006] For example, PHB has a melting point of around 175°C. However, as a poly(3-hydroxy fatty acid ester) (P3HA), its molecular chain scission begins at 160°C. Therefore, even a single heat treatment can significantly impact its performance. Even after pelletization, its molecular weight can be halved, and its strength can drop by 5-30%, making it difficult to use stably and effectively. PHBV also faces similar challenges. PHBHHx, however, suffers from insufficient crystallinity and often lacks strength, limiting its application in applications such as injection molding, fibers, 3D printing, sheets, and straws. To address this issue, researchers are introducing 4HA (4-hydroxy fatty acid) or 2HA (2-hydroxy fatty acid) monomers to improve the thermal stability of the material and prevent premature chain scission, such as in P34HB and P(HA-LA). However, a high ratio of 4HB to LA is required to achieve significant improvements in thermal stability. Consequently, the copolymer tends to become semi-crystalline or amorphous, significantly reducing its strength.

[0007] However, for applications that require high transparency, good toughness, and fast crystallization rate, such as sheets, plates, films, and packaging materials, all existing types of PHA materials are insufficient. For example, PHB and PHBV have high melting points and are hard and brittle; PHBHHx and P34HB have slow crystallization rates and severe post-crystallization. To this end, people usually think of solutions that add various nucleating agents to accelerate the crystallization rate of PHBHHx and P34HB, or blend PHB / PHBV with PHBHHx / P34HB, two types of hard and soft materials, but it is difficult to improve the performance to the ideal state. In particular, the crystallization rate (the inverse of which is t 1 / 2 , that is, the time required for the polymer crystallization process to be halfway completed) has a great impact. Since PHA has a low glass transition temperature (around 0°C), it can only be solidified by crystallization at room temperature. Therefore, for the application scenarios of thin products such as sheets, plates, films, and packaging materials, if the crystallization rate is not fast enough, the molding speed will be seriously slowed down. In addition, the spherulites of post-crystallization are large, which makes the material brittle and greatly affects the transparency of the product. All these have restricted the application of PHA in the direction of thin products.

[0008] In addition, in scenarios such as adhesives, coatings, and pigments, acrylic resin has become the most widely used material, but it has the defect of not being marine degradable. Many of the commonly used curing agents, stabilizers, cross-linking agents, etc. are not environmentally friendly additives, so it is difficult to meet higher environmental protection requirements. Other relatively environmentally friendly adhesive materials, such as starch, gelatin, and PVA, have low peel strength and poor mechanical properties. The degradation rate of the latter is very slow, and accelerators need to be added to increase its degradation rate. The strength of PVA after film formation is also insufficient. For high adhesion and mechanical properties, composite adhesives are often better. However, these adhesives have a slow curing speed, are not marine degradable, and do not have pressure-sensitive curing and the ability to quickly exert adhesive functions.

[0009] Therefore, there is an urgent need to develop marine-degradable materials that also possess various other excellent properties (such as high strength, high crystallinity, and low melting point, or high transparency, good toughness, fast crystallization rate, and small spherulites, or high peel strength and pressure-sensitive curing properties) to meet environmental protection, low carbon, and practical application requirements. In view of this, the present invention is proposed. Summary of the Invention

[0010] The embodiments of the present application provide a polyhydroxyalkanoate composition, a preparation method, and an application thereof. The polyhydroxyalkanoate composition comprises a specific PHA terpolymer, which can achieve numerous excellent properties, including marine degradability, with little or no use of additives.

[0011] The solution provided by the present invention is as follows:

[0012] In a first aspect, the present invention provides a polyhydroxyalkanoate (PHA) composition comprising a PHA terpolymer, wherein the PHA terpolymer is P3HB4HB3HV and / or P3HB4HB5HV, wherein the molar content of the repeating unit 3HB in the PHA terpolymer is greater than 94%, and the weight-average molecular weight of the PHA terpolymer is greater than 300,000. This polyhydroxyalkanoate composition meets the requirements of marine degradability, high strength, high crystallinity, and a low melting point, resulting in an environmentally friendly, low-carbon, and high-performance product.

[0013] The polyhydroxyalkanoate composition of the present invention utilizes a PHA terpolymer of a specific type and copolymer unit ratio, namely P3HB4HB3HV and / or P3HB4HB5HV, wherein the molar content of the repeating unit 3HB is greater than 94% and the weight-average molecular weight is greater than 300,000. Experiments have confirmed that, due to the high proportion of 3HB, the PHA terpolymer exhibits material properties similar to those of a crystalline polymer, with high crystallinity and a high load deflection temperature. The presence of three comonomers also provides toughness, while the medium-to-high molecular weight maintains high strength. Furthermore, the introduction of the third monomer, 3HV or 5HV, with the molar content limited to less than 6%, surprisingly lowers the melting point of the polymer, thereby avoiding thermal degradation such as molecular chain breakage caused by excessively high processing temperatures during heat treatment, ensuring high performance retention before and after processing.

[0014] Because the PHA terpolymer of the present invention is marine degradable, highly crystallinity-rich, and relatively strong, possessing both moderate toughness, a high deflection temperature under load, and a low melting point, its basic properties meet the requirements for molded products, including molded parts, extruded parts, wiredrawn parts, fiber products, 3D-printed parts, and sheet / plate-shaped products. Therefore, it can meet product application requirements without the addition of additives. Therefore, the present invention streamlines the formulation, reduces costs, and contributes to environmental protection while ensuring product quality and stability.

[0015] It should be noted that the PHA terpolymer described herein can be composed of P3HB4HB3HV and P3HB4HB5HV in any ratio; it can also be pure P3HB4HB3HV or pure P3HB4HB5HV. Pure P3HB4HB3HV can be a single substance, i.e., the molar content of the three repeating units 3HB, 4HB, and 3HV in P3HB4HB3HV is fixed and unique; or it can be a combination, i.e., P3HB4HB3HV comprises two or more terpolymers with different molar contents of the repeating units 3HB, 4HB, and 3HV, such as P3HB4HB3HV with a 94% molar content of 3HB, a 3% molar content of 4HB, and a 3% molar content of 3HV, and P3HB4HB3HV with a 96% molar content of 3HB, a 2% molar content of 4HB, and a 2% molar content of 3HV. Similarly, pure P3HB4HB5HV can be a single substance or a combination.

[0016] In some embodiments of the present invention, the PHA terpolymer has a crystallinity of 30% to 70% and a melting point below 155°C.

[0017] The melting point is below 155°C, thus avoiding thermal degradation such as molecular chain breakage caused by processing temperatures above 160°C due to the high melting point. To meet this melting point requirement, the weight-average molecular weight of the PHA terpolymer must be between 300,000 and 3,000,000.

[0018] In some embodiments of the present invention, the polyhydroxyalkanoate composition may contain other PHA homopolymers or copolymers in addition to the PHA terpolymer. However, in order to achieve good results, the mass proportion of the PHA terpolymer in the polyhydroxyalkanoate composition must be greater than 60%.

[0019] For example, the polyhydroxyalkanoate composition is composed of P3HB4HB5HV and PHB, wherein the mass fraction of P3HB4HB5HV is greater than 70%. For another example, the polyhydroxyalkanoate composition is composed of P3HB4HB3HV, PHB, and P34HB, wherein the mass fraction of P3HB4HB3HV is greater than 60%.

[0020] In some embodiments of the present invention, according to the GB / T 1634.2 test standard, the load deformation temperature of the polyhydroxyalkanoate composition is above 85°C.

[0021] In some embodiments of the present invention, according to the GB / T 1040.2 test standard, the polyhydroxyalkanoate composition has a tensile strength greater than 18 MPa and an elongation at break greater than 5%.

[0022] It is understood that in order to further improve the material properties, the polyhydroxyalkanoate composition may further include an auxiliary agent, wherein the auxiliary agent is selected from one or more of a nucleating agent, a chain extender, an antioxidant, a plasticizer, and a filler.

[0023] As described above, the PHA terpolymer of the present invention has excellent properties itself, so even if an auxiliary agent is added, the required amount of the auxiliary agent is very small.

[0024] In some embodiments of the present invention, based on the mass of the polyhydroxyalkanoate composition, the amount of the nucleating agent added is 0.01-2%, the amount of the chain extender added is 0.1-2%, the amount of the antioxidant added is 0.1-2%, the amount of the plasticizer added is 0.1-2%, and the amount of the filler added is 0.1-30%.

[0025] In some embodiments of the present invention, the nucleating agent is selected from hexagonal crystal structure compounds (such as boron nitride, silicon nitride, titanium nitride, boron carbide, silicon carbide, titanium carbide, magnesium oxide, aluminum oxide), pyrimidines (such as uracil, thymine, cytosine), purines (such as adenine, guanine), dicarboxylic acid salicylic acid hydrazide, melamine, sugar alcohol compounds (such as pentaerythritol, isosorbide, sorbitol, mannitol, maltitol, erythritol), fatty acid amides (such as EBS, erucamide, oleamide, linoleamide, palmitic acid amide), TMC300 and TMC 306 of Shanxi Chemical Research Institute, or one or more thereof.

[0026] In some embodiments of the present invention, the chain extender is selected from one or more of isocyanates (such as toluene diisocyanate (TDI), isophorone diisocyanate (IPDI), diphenylmethane diisocyanate (MDI), dicyclohexylmethane diisocyanate (HMDI), hexamethylene diisocyanate (HDI), lysine diisocyanate (LDI), 1,5-naphthalene diisocyanate (NDI)), BASF Joncryl ADR-4400 / ADR-4468, Shanxi Chemical Research Institute KL-E series, Japan Catalyst EPOCROS RPS1005, 1,3-bis(2-oxazoline)benzene (MPBO), 2,2'-(1,3-phenylene)-bisoxazoline, and trimethylolpropane chain extender.

[0027] In some embodiments of the present invention, the antioxidant is selected from one or more of antioxidant 1010, antioxidant 1076, antioxidant BHT, antioxidant 1098, antioxidant 245, antioxidant 168, antioxidant DSTP, antioxidant 412S, antioxidant DLTP, antioxidant PEPQ, carbodiimide, polymerized carbodiimide, HyMax 1010, TNK-01, KSJ-936, DuPont 132F NC010, German Lasig STABILIZER 7000, Rhein Chemical Stabaxol P, American Doverphos Chemical Doverphos S-9228, and stearate.

[0028] In some embodiments of the present invention, the plasticizer is selected from one or more of isosorbide dioctanoate, acetylated ricinoleic acid dimethyl glycerol, epoxy tetrahydrophthalate, castor oil, polyethylene glycol series, polypropylene glycol series, acetyl tributyl citrate, acetyl tributyl ethyl citrate, epoxy soybean oil, glycerol, triacetin, fatty acids (e.g., dodecanoic acid, tetradecanoic acid, hexadecanoic acid, octadecanoic acid, eicosanoic acid, docosanoic acid, tetracosanoic acid, hexacosanoic acid, octacosanoic acid, triacontanol), fatty alcohols (e.g., dodecanol, tetradecanol, hexadecanol, octacosanoic acid, eicosanoic acid, docosanoic acid, tetracosanoic acid, hexacosanoic acid, octacosanoic acid, triacontanol), and fatty alcohols (e.g., dodecanol, tetradecanol, hexadecanol, octacosanoic acid, eicosanoic acid, docosanoic acid, tetracosanoic acid, hexacosanoic acid, octacosanoic acid, triacontanol).

[0029] In some embodiments of the present invention, the filler is selected from one or more of clay, calcium carbonate, talc, kaolin, montmorillonite, bentonite, silicon dioxide, chitin, titanium dioxide, cellulose, and pregelatinized starch.

[0030] Furthermore, the present invention provides a method for preparing the polyhydroxyalkanoate composition.

[0031] The preparation method provided by the present invention includes the step of mixing the PHA terpolymer with other components. It is understood that when the polyhydroxyalkanoate contains only one PHA terpolymer and does not include other components such as additives, no mixing is required.

[0032] In some embodiments of the present invention, the PHA terpolymer is obtained by fermentation culture of recombinant bacteria.

[0033] Specifically, the preparation of the terpolymer P3HB4HB3HV may refer to the applicant's prior application CN114134096A, and the preparation of the terpolymer P3HB4HB5HV may refer to the applicant's prior application CN113684169A.

[0034] In CN114134096A, the applicant studied how to construct halophilic bacteria for synthesizing P3HB4HB3HV, and explored how to increase the 4HB ratio and / or 3HV ratio, such as introducing dhaT and aldD genes into halophilic bacteria to increase the 4HB ratio; knocking out gabD and sad genes in halophilic bacteria to increase the 4HB ratio; knocking out sdhA and sdhE genes in halophilic bacteria to increase the 3HV ratio; and adjusting the feeding strategy during batch fed-batch fermentation to adjust the 4HB ratio and 3HV ratio. In short, the applicant had been trying every possible way to study how to increase the 4HB ratio and / or 3HV ratio in P3HB4HB3HV, but did not prepare P3HB4HB3HV with a 3HB content of more than 94% and characterize its performance. At that time, the prior art did not provide relevant technical inspiration to guide the applicant to prepare P3HB4HB3HV with a 3HB content of more than 94%. The applicant unexpectedly discovered during this research and development that P3HB4HB3HV, with a 3HB content of more than 94% and a weight-average molecular weight between 300,000 and 3 million, has good performance and meets the requirements of marine degradability, high strength, high crystallinity and low melting point.

[0035] Similarly, the applicant studied how to construct halophilic bacteria to synthesize P3HB4HB5HV in CN113684169A and explored how to obtain P3HB4HB5HV with different 4HB and / or 5HV ratios. However, they did not prepare P3HB4HB5HV with a 3HB content of 94% or more and characterize its properties. The applicant unexpectedly discovered during this research and development that P3HB4HB5HV with a 3HB content of 94% or more and a weight-average molecular weight between 300,000 and 3,000,000 exhibits excellent properties, meeting the requirements of marine degradability, high strength, high crystallinity, and a low melting point.

[0036] Furthermore, the present invention provides a PHA powder comprising the above-mentioned polyhydroxyalkanoate composition.

[0037] In some embodiments of the present invention, the PHA powder composition is the above-mentioned polyhydroxyalkanoate composition.

[0038] The PHA terpolymer produced by microbial fermentation is in powder form, which can be mixed with optional additives to obtain PHA powder.

[0039] Furthermore, the present invention provides a PHA pellet comprising the polyhydroxyalkanoate composition.

[0040] In some embodiments of the present invention, the composition of the PHA pellets is the above-mentioned polyhydroxyalkanoate composition.

[0041] The PHA pellets can be obtained by granulating PHA powder as a raw material using conventional granulation methods in the art (including but not limited to extrusion granulation).

[0042] Furthermore, the present invention provides a PHA molded product comprising the polyhydroxyalkanoate composition.

[0043] In some embodiments of the present invention, the composition of the PHA molded body is the above-mentioned polyhydroxyalkanoate composition.

[0044] In the art, the steps for preparing PHA molded articles typically involve first converting PHA powder into PHA pellets, and then converting the PHA pellets into corresponding molded articles through either thermal or non-thermal processing. Of course, the present invention does not exclude the possibility of directly preparing PHA molded articles from PHA powder, for example, directly preparing sheets from PHA powder.

[0045] In some embodiments of the present invention, the PHA molded article is a molded product, an extruded product, a wire drawing product, a fiber product, a 3D printed product, a foamed product, a sheet product, or a plate product. It is understood that the molded product is obtained by injection molding, vacuum forming, or blow molding, the extruded product is obtained by extrusion molding, the 3D printed product is obtained by 3D printing, and the same applies to the remaining products. The resulting PHA molded article can include various forms, such as pellets, vacuum forming parts, straws, blow molding parts, injection molding parts, rigid strips, filaments, staple fibers, 3D printing wires, 3D printed parts, wire drawing parts, foamed parts, sheets, plates, etc.

[0046] In some embodiments of the present invention, the preparation method of the polyhydroxyalkanoate granules is as follows:

[0047] The components of the polyhydroxyalkanoate composition are weighed according to a set mass ratio, and then blended using a high-speed mixer at room temperature at a speed of 50-500 r / min for 0.5-5 minutes. The above mixture is fed into the feed port of a screw extruder. The processing temperature is set within the range of 100-160°C. The feed rate or production capacity is adjusted according to the actual production status. Pellets are obtained using a pelletizer.

[0048] The PHA molded body is prepared by feeding the above polyhydroxyalkanoate pellets into the feed port of the corresponding processing equipment, setting the processing temperature within the range of 110-175°C, and adjusting the feed rate or production capacity according to the actual production status to produce the corresponding product.

[0049] The present invention provides a polyhydroxyalkanoate composition, a preparation method, and an application thereof. Since the polyhydroxyalkanoate composition comprises P3HB4HB3HV and / or P3HB4HB5HV with a 3HB molar content of more than 94% and a weight-average molecular weight of more than 300,000, the obtained polyhydroxyalkanoate composition can meet the requirements of marine degradability, high strength, high crystallinity, and low melting point, thereby obtaining an environmentally friendly, low-carbon, and high-performance product.

[0050] In a second aspect, the present invention provides a polyhydroxyalkanoate (PHA) composition comprising a PHA terpolymer, wherein the PHA terpolymer is P3HB4HB3HV and / or P3HB4HB5HV. The molar content of 3HB in the PHA terpolymer is less than 94%, and the molar ratio of 4HB to 3HV or 5HV is less than 0.16. The PHA terpolymer has a weight-average molecular weight between 200,000 and 2,000,000. This polyhydroxyalkanoate composition meets the requirements of marine degradation, high transparency, good toughness, fast crystallization rate, and small spherulites, resulting in an environmentally friendly, low-carbon, and high-performance product.

[0051] The polyhydroxyalkanoate (PHA) terpolymers of the present invention utilize specific copolymerization unit ratios (P3HB4HB3HV and / or P3HB4HB5HV) with a 3HB molar content of less than 94% and a 4HB to 3HV or 5HV molar ratio of less than 0.16 (i.e., the 3HV or 5HV content significantly exceeds the 4HB content). The weight-average molecular weight ranges from 200,000 to 2,000,000. Experiments have confirmed that despite the low 3HB content and the material properties tending toward semi-crystalline polymers, the presence of 3HV or 5HV unexpectedly increases the material's crystallization rate and reduces the size of the spherulites. According to preliminary analysis, this is because when the 3HB monomer is the main component (≥46.3mol%), the 3HV or 5HV chain segments easily form micro-nano-scale fine spherulites (the number of carbon atoms in the side chains of 3HV is similar to that in the main chain, the main chain is difficult to curl, the rigidity is large, and the side chain units form spherulite nuclei; the main chain of 5HV is longer but still short, so after rotation and folding within the three-dimensional structure, the rigidity is still large, and the main chain units form spherulites; the main chain of 4HB has one less carbon than that of 5HV, which is inconvenient to rotate and fold into small nuclei within the three-dimensional structure, and it is easier to form a flexible ring structure, which will destroy the crystallization behavior to a certain extent). The 3HB unit will grow and crystallize in this way, and 3HV or 5HV is uniformly present in it like filling and has a nucleation effect. In addition, the small amount of 4HB monomer destroys the upper limit of crystallinity, so the overall material presents a semi-crystalline structure with rapid crystallization and fine crystallization, high transparency, low haze, and mechanical properties with both strength and toughness. On the contrary, when the content of 3HB monomer is small and 3HV or 5HV is the main component, 3HB in turn forms a rigid and short chain segment, which can easily serve as a crystal nucleus to promote the rapid crystallization of 3HV or 5HV, and a small amount of 4HB monomer still acts as a flexible chain segment to reduce the crystallinity.

[0052] Because the PHA terpolymer of the present invention is marine degradable, highly transparent, tough, rapidly crystallizes, and has small spherulites, its basic properties meet the requirements for thin products such as sheets, plates, films, and packaging materials. Therefore, it can meet product application requirements with minimal or no additives. Therefore, the present invention streamlines the formulation, reduces costs, and contributes to environmental protection while ensuring product quality and stability.

[0053] It should be noted that the PHA terpolymer described herein can be composed of P3HB4HB3HV and P3HB4HB5HV in any ratio; it can also be pure P3HB4HB3HV or pure P3HB4HB5HV. Pure P3HB4HB3HV can be a single substance, i.e., the molar content of the three repeating units 3HB, 4HB, and 3HV in P3HB4HB3HV is fixed and unique; or it can be a combination, i.e., P3HB4HB3HV comprises two or more terpolymers with different molar contents of the repeating units 3HB, 4HB, and 3HV, such as P3HB4HB3HV with a 3HB content of 93%, a 4HB content of 0.9%, and a 3HV content of 6.1%, and P3HB4HB3HV with a 3HB content of 90%, a 4HB content of 1%, and a 3HV content of 9%. Similarly, pure P3HB4HB5HV can be a single substance or a combination.

[0054] In some embodiments of the present invention, the half crystallization time t of the PHA terpolymer at 60°C is 1 / 2 The crystallization temperature Tc is between 50-85℃ during 10-30s.

[0055] The polyhydroxyalkanoate composition of the present invention introduces a third monomer, 3HV or 5HV, having a molar content of more than six times that of 4HB, compared to P34HB having the same molar content of 4HB. Surprisingly, it is found that the crystallinity of the polymer is not significantly reduced, while the crystallization rate is greatly improved. At the same time, the melting point is further reduced (below 155° C.). This avoids the occurrence of thermal degradation such as molecular chain breakage caused by setting a processing temperature above 160° C. due to the high melting point, thereby ensuring high performance retention of the material before and after processing. It also avoids the occurrence of a significant reduction in mechanical strength due to low crystallinity.

[0056] In some embodiments of the present invention, the polyhydroxyalkanoate composition may contain other PHA homopolymers or copolymers in addition to the PHA terpolymer. However, in order to achieve good results, the mass proportion of the PHA terpolymer in the polyhydroxyalkanoate composition must be greater than 70%.

[0057] For example, the polyhydroxyalkanoate composition is composed of P3HB4HB5HV and PHB, wherein the mass fraction of P3HB4HB5HV is greater than 70%. For another example, the polyhydroxyalkanoate composition is composed of P3HB4HB3HV, PHB, and P34HB, wherein the mass fraction of P3HB4HB3HV is greater than 70%.

[0058] In some embodiments of the present invention, according to the GB / T 2410 Method A test standard, for a thickness of 100 μm, the light transmittance of the polyhydroxyalkanoate composition is greater than 81.5% and the haze is less than 8.5%.

[0059] In some embodiments of the present invention, according to the GB / T 1040.2 test standard, the polyhydroxyalkanoate composition has a tensile strength greater than 3.5 MPa and an elongation at break greater than 25%.

[0060] It is understood that in order to further improve the material properties, the polyhydroxyalkanoate composition further includes an auxiliary agent, which is selected from one or more of a nucleating agent, a chain extender, an antioxidant, a plasticizer, and a filler.

[0061] As described above, the PHA terpolymer of the present invention has excellent properties itself, so even if an auxiliary agent is added, the required amount of the auxiliary agent is very small.

[0062] In some embodiments of the present invention, based on the mass of the polyhydroxyalkanoate composition, the amount of the nucleating agent added is 0.01-2%, the amount of the chain extender added is 0.1-2%, the amount of the antioxidant added is 0.1-2%, the amount of the plasticizer added is 0.1-2%, and the amount of the filler added is 0.1-30%.

[0063] In some embodiments of the present invention, the nucleating agent is selected from hexagonal crystal structure compounds (such as boron nitride, silicon nitride, titanium nitride, boron carbide, silicon carbide, titanium carbide, magnesium oxide, aluminum oxide), pyrimidines (such as uracil, thymine, cytosine), purines (such as adenine, guanine), dicarboxylic acid salicylic acid hydrazide, melamine, sugar alcohol compounds (such as pentaerythritol, isosorbide, sorbitol, mannitol, maltitol, erythritol), fatty acid amides (such as EBS, erucamide, oleamide, linoleamide, palmitic acid amide), TMC300 and TMC 306 of Shanxi Chemical Research Institute, or one or more thereof.

[0064] In some embodiments of the present invention, the chain extender is selected from one or more of isocyanates (such as toluene diisocyanate (TDI), isophorone diisocyanate (IPDI), diphenylmethane diisocyanate (MDI), dicyclohexylmethane diisocyanate (HMDI), hexamethylene diisocyanate (HDI), lysine diisocyanate (LDI), 1,5-naphthalene diisocyanate (NDI)), BASF Joncryl ADR-4400 / ADR-4468, Shanxi Chemical Research Institute KL-E series, Japan Catalyst EPOCROS RPS1005, 1,3-bis(2-oxazoline)benzene (MPBO), 2,2'-(1,3-phenylene)-bisoxazoline, and trimethylolpropane chain extender.

[0065] In some embodiments of the present invention, the antioxidant is selected from one or more of antioxidant 1010, antioxidant 1076, antioxidant BHT, antioxidant 1098, antioxidant 245, antioxidant 168, antioxidant DSTP, antioxidant 412S, antioxidant DLTP, antioxidant PEPQ, carbodiimide, polymerized carbodiimide, HyMax 1010, TNK-01, KSJ-936, DuPont 132F NC010, German Lasig STABILIZER 7000, Rhein Chemical Stabaxol P, American Doverphos Chemical Doverphos S-9228, and stearate.

[0066] In some embodiments of the present invention, the plasticizer is selected from one or more of isosorbide dioctanoate, acetylated ricinoleic acid dimethyl glycerol, epoxy tetrahydrophthalate, castor oil, polyethylene glycol series, polypropylene glycol series, acetyl tributyl citrate, acetyl tributyl ethyl citrate, epoxy soybean oil, glycerol, triacetin, fatty acids (e.g., dodecanoic acid, tetradecanoic acid, hexadecanoic acid, octadecanoic acid, eicosanoic acid, docosanoic acid, tetracosanoic acid, hexacosanoic acid, octacosanoic acid, triacontanol), fatty alcohols (e.g., dodecanol, tetradecanol, hexadecanol, octacosanoic acid, eicosanoic acid, docosanoic acid, tetracosanoic acid, hexacosanoic acid, octacosanoic acid, triacontanol), and fatty alcohols (e.g., dodecanol, tetradecanol, hexadecanol, octacosanoic acid, eicosanoic acid, docosanoic acid, tetracosanoic acid, hexacosanoic acid, octacosanoic acid, triacontanol).

[0067] In some embodiments of the present invention, the filler is selected from one or more of clay, calcium carbonate, talc, kaolin, montmorillonite, bentonite, silicon dioxide, chitin, titanium dioxide, cellulose, and pregelatinized starch.

[0068] Furthermore, the present invention provides a method for preparing the polyhydroxyalkanoate composition

[0069] The preparation method provided by the present invention includes the step of mixing the PHA terpolymer with other components. It is understood that when the polyhydroxyalkanoate contains only one PHA terpolymer and does not include other components such as additives, no mixing is required.

[0070] In some embodiments of the present invention, the PHA terpolymer is obtained by fermentation culture of recombinant bacteria.

[0071] Furthermore, the present invention provides a PHA powder comprising the above-mentioned polyhydroxyalkanoate composition.

[0072] In some embodiments of the present invention, the PHA powder composition is the above-mentioned polyhydroxyalkanoate composition.

[0073] The PHA terpolymer produced by microbial fermentation is in powder form, which can be mixed with optional additives to obtain PHA powder.

[0074] Furthermore, the present invention provides a PHA pellet comprising the polyhydroxyalkanoate composition.

[0075] In some embodiments of the present invention, the composition of the PHA pellets is the above-mentioned polyhydroxyalkanoate composition.

[0076] The PHA pellets can be obtained by granulating PHA powder as a raw material using conventional granulation methods in the art (including but not limited to extrusion granulation).

[0077] Furthermore, the present invention provides a PHA molded product comprising the polyhydroxyalkanoate composition.

[0078] In some embodiments of the present invention, the composition of the PHA molded body is the above-mentioned polyhydroxyalkanoate composition.

[0079] In the art, the steps for preparing PHA molded articles typically involve first converting PHA powder into PHA pellets, and then converting the PHA pellets into corresponding molded articles through either thermal or non-thermal processing. Of course, the present invention does not exclude the possibility of directly preparing PHA molded articles from PHA powder, for example, directly preparing sheets from PHA powder.

[0080] In some embodiments of the present invention, the PHA molded body is a thin product, including but not limited to a plate, a sheet, a film, a strip, a packaging material, etc.

[0081] The thickness of the thin product is in the range of 10μm-5mm. Specifically, the thickness of the plate is 0.8-5mm, the thickness of the sheet is 0.2-0.8mm, and the thickness of the film is 10μm-0.2mm. As for the thickness of the strips and packaging materials, it depends on specific needs and does not exceed the range of 10μm-5mm.

[0082] For example, film materials include optical film, cast film, calendered film, blown film, composite film, shopping bags, garbage bags, packaging bags, ziplock bags, heat shrink film, stretch film, agricultural film, ground film, aluminized film, composite film, film and fabric composite materials, i.e. artificial leather and other products.

[0083] Strips include ribbons, adhesive tapes, packing tapes and other products.

[0084] Packaging materials include packaging bags, packaging shells (toys, stationery, toiletries, cosmetics, gifts), cushioning air column bags, bubble bags, bubble film, pearl cotton, cable jackets, packing tapes, candy wrappers, medicine plates and other products.

[0085] The molding process of the molded body is not limited and can be selected from conventional processing methods (injection molding, vacuum molding, blow molding, extrusion, biaxial stretching, calendering, casting, etc.) according to specific needs.

[0086] In some embodiments of the present invention, the preparation method of the polyhydroxyalkanoate granules is as follows:

[0087] The components of the polyhydroxyalkanoate composition are weighed according to a set mass ratio, and then blended using a high-speed mixer at room temperature at a speed of 50-500 r / min for 10 seconds to 5 minutes. The above mixture is fed into the feed port of a screw extruder. The processing temperature is set within the range of 50-160°C. The feed rate or production capacity is adjusted according to the actual production status. Pellets are obtained using a pelletizer.

[0088] The PHA molded body is prepared by feeding the above polyhydroxyalkanoate pellets into the feed port of the corresponding processing equipment, setting the processing temperature within the range of 50-175°C, and adjusting the feed rate or production capacity according to the actual production status to produce the corresponding product.

[0089] The present invention provides a polyhydroxyalkanoate composition, a preparation method thereof, and an application thereof. The polyhydroxyalkanoate composition comprises P3HB4HB3HV and / or P3HB4HB5HV with a 3HB molar content of less than 94%, a 4HB to 3HV or 5HV molar content ratio of less than 0.16, and a weight-average molecular weight of 200,000 to 2,000,000. Therefore, the obtained polyhydroxyalkanoate composition has the advantages of being marine degradable, having high transparency, good toughness, fast crystallization rate, and small spherulites, and can be used to prepare thin products.

[0090] In a third aspect, the present invention provides a polyhydroxyalkanoate (PHA) terpolymer comprising PHA (P3HB4HB3HV), P3HB4HB5HV, or a combination thereof, wherein the molar content of the repeating unit 3HB is less than 94%, the molar ratio of 4HB to 3HV or 5HV is greater than 4.2, and the weight-average molecular weight of the PHA terpolymer is between 8,000 and 200,000. This polyhydroxyalkanoate composition can meet the requirements of marine degradation, high peel strength, and pressure-sensitive curing properties, resulting in an environmentally friendly, low-carbon, and high-performance adhesive, dressing, coating, pigment, ink, or the like.

[0091] The polyhydroxyalkanoate (PHA) terpolymer of the present invention utilizes a specific type and copolymer unit ratio of PHAs, namely P3HB4HB3HV and / or P3HB4HB5HV, wherein the molar content of the repeating unit 3HB is less than 94%, the molar ratio of 4HB to 3HV or 5HV is greater than 4.2 (i.e., the 4HB content is significantly greater than that of 3HV or 5HV), and the weight-average molecular weight is between 8,000 and 200,000. Experiments have confirmed that this PHA terpolymer, due to its low 3HB content and low molecular weight, is an amorphous polymer with good flexibility and is suitable for film and gel formation. Compared to P34HB, which has a higher 4HB ratio, the presence of 3HV and / or 5HV unexpectedly exhibits pressure-sensitive curing properties.

[0092] The inventors deduced that the most likely reason is that when the 3HB monomer is the main component (≥44.7 mol%), the proportion of 3HV or 5HV is very small, and its chain segments easily form micro-nano-scale tiny spherulites (the number of carbon atoms in the side chains of 3HV is similar to that in the main chain, the main chain is difficult to curl, the rigidity is large, and the branch units form spherulite nuclei; the main chain of 5HV is longer, but still short, so after rotation and folding within the three-dimensional structure, the rigidity is still large, and the main chain units form spherulites); and although 4HB is less than 3HB, it is far more than 3HV or 5HV. The main chain of 4HB has one less carbon than 5HV, which makes it inconvenient to rotate and fold into small crystal nuclei within the three-dimensional structure. It is more likely to form a flexible ring structure, which will destroy the crystallization behavior of 3HB, so the material as a whole is an amorphous polymer. However, when external pressure is applied to the material, the macromolecules of the PHA terpolymer undergo displacement, distortion, rearrangement, and other changes, making its overall arrangement more orderly. Regular structures such as small spherulites of 3HV or 5HV grow rapidly. Under the influence of this effect, the 3HB units around it will grow and crystallize in this way, and 4HB exists evenly in it like a filler. Even if the upper limit of crystallinity is destroyed, it is still difficult to prevent the rapid solidification of the entire material, so it finally presents the characteristics of pressure-sensitive crystallization and solidification. When the 4HB monomer is the main monomer (≥44.7mol%), the principle is similar. 3HB becomes the existence that destroys the crystallization of 4HB, but under pressure, 4HB is still easily induced by a small amount of 3HV or 5HV to rapidly solidify. This characteristic can make the PHA terpolymer more convenient and efficient in application.

[0093] Furthermore, the polyhydroxyalkanoate composition of the present invention has a lower molecular weight than medium- and high-molecular-weight PHAs, resulting in a higher number of terminal hydroxyl groups and the presence of free monomers, which enhances its hydrophilicity and significantly increases its surface activity, thereby ensuring high peel strength. Combined with its pressure-sensitive curing properties, the pure material can fully meet the requirements of applications such as adhesives, sizing for dressings, and water-based coatings for paper. The addition of additives is minimal or even non-existent, allowing for a streamlined formulation, reduced costs, and environmentally friendly performance while ensuring product quality and stability.

[0094] Furthermore, the polyhydroxyalkanoate composition of the present invention is gentle on the skin, has good human compatibility, and surprisingly exhibits excellent antibacterial properties, likely due to the presence of the free monomer 3HB. Therefore, in specific applications such as tourniquets and bandages, this composition significantly reduces wound irritation and promotes wound healing.

[0095] It should be noted that the PHA terpolymer described herein can be composed of P3HB4HB3HV and P3HB4HB5HV in any ratio; it can also be pure P3HB4HB3HV or pure P3HB4HB5HV. Pure P3HB4HB3HV can be a single substance, i.e., the molar content of the three repeating units 3HB, 4HB, and 3HV in P3HB4HB3HV is fixed and unique; or it can be a combination, i.e., P3HB4HB3HV comprises two or more terpolymers with different molar contents of the repeating units 3HB, 4HB, and 3HV, such as P3HB4HB3HV with a 3HB content of 56%, a 4HB content of 36%, and a 3HV content of 8%, and P3HB4HB3HV with a 3HB content of 72%, a 4HB content of 25%, and a 3HV content of 3%. Similarly, pure P3HB4HB5HV can be a single substance or a combination.

[0096] In some embodiments of the present invention, in addition to the PHA terpolymer, the polyhydroxyalkanoate composition may also contain a PHA binary copolymer of the same low molecular weight (8,000-200,000). However, in order to achieve a good effect, the mass proportion of the PHA terpolymer in the polyhydroxyalkanoate composition must be greater than 70%.

[0097] For example, the polyhydroxyalkanoate composition is composed of P3HB4HB3HV and P34HB (molecular weight between 8,000 and 200,000), wherein the mass fraction of P3HB4HB3HV is above 70%.

[0098] However, it should be noted that the polyhydroxyalkanoate composition of the present invention is intended for use in adhesives, coatings, dressings, and the like, and is in liquid, gel, or soft solid form and is not suitable for thermal processing. Therefore, it cannot be blended with other crystalline PHAs, i.e., the polyhydroxyalkanoate composition does not contain crystalline polyhydroxyalkanoate.

[0099] In some embodiments of the present invention, the half-crystallization time t of the PHA terpolymer measured at 60°C is 1 / 2 Above 1200s.

[0100] Furthermore, the PHA terpolymer is subjected to a pressure of 50 kPa-2 MPa at 60 ° C. and the measured half-crystallization time t 1 / 2 Between 1-300s.

[0101] In some embodiments of the present invention, according to the GB / T 1040.2 test standard, the tensile strength of the PHA terpolymer is between 0.12-3.3 MPa, and the elongation at break is not less than 220%.

[0102] In some embodiments of the present invention, according to the GB / T 2791 test standard, the peel strength of the polyhydroxyalkanoate composition is not less than 0.35 kN / m.

[0103] It is understood that in order to further improve the material properties, the polyhydroxyalkanoate composition may further include an auxiliary agent, wherein the auxiliary agent is selected from one or more of a curing agent, a solvent, a plasticizer, a coupling agent, a thickener, and a filler.

[0104] As described above, the PHA terpolymer of the present invention has excellent properties itself, so even if an auxiliary agent is added, the required amount of the auxiliary agent is very small.

[0105] In some embodiments of the present invention, based on the mass of the polyhydroxyalkanoate composition, the added amount of the curing agent is 0.1-5%, the added amount of the solvent is 1-80%, the added amount of the plasticizer is 0.1-5%, the added amount of the coupling agent is 0.1-2%, the added amount of the thickener is 0.1-2.5%, and the added amount of the filler is 0.1%-8%.

[0106] In some embodiments of the present invention, the curing agent includes one or more of aliphatic polyamines, alicyclic polyamines, low molecular weight polyamides, and modified aromatic amines.

[0107] In some embodiments of the present invention, the solvent includes one or more of water, ethanol, ethylene glycol, n-propanol, propylene glycol, glycerol, acetone, isobutanol, 1,4-butanediol, methyl ethyl ketone, isoamyl alcohol, ethyl acetate, propyl acetate, butyl acetate, ethylene glycol diacetate, ethylene glycol dibutyrate, limonene, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, 1-allyl-3-methylimidazolium chloride, 1-ethyl-3-methylimidazolium acetate, tributylmethylammonium bis(trifluoromethylsulfonyl)imide, 1-ethyl-3-methylimidazolium dicyanamide, 1-ethyl-3-methylimidazolium ethyl sulfate, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, or 1-butyl-3-methylimidazolium tetrafluoroborate.

[0108] In some embodiments of the present invention, the plasticizer includes one or more of isosorbide dioctanoate, acetylated ricinoleic acid dimethyl glycerol, epoxy tetrahydrophthalate, castor oil, polyethylene glycol series (polyethylene glycol with different molecular weight, viscosity or acidity is selected according to actual conditions in the specific embodiment), polypropylene glycol series, acetyl tributyl citrate, acetyl tributyl ethyl citrate, epoxy soybean oil, glycerol, triacetin, fatty acid plasticizers (dodecanoic acid, tetradecanoic acid, hexadecanoic acid, octadecanoic acid, eicosanoic acid, docosanoic acid, tetracosanoic acid, hexacosanoic acid, octacosanoic acid, triacontanol), and fatty alcohol plasticizers (dodecanol, tetradecanol, hexadecanol, octadecyl alcohol, eicosanol, docosanol, tetracosanol, hexacosanol, octacosanol, triacontanol, and dotriacontanol).

[0109] In some embodiments of the present invention, the coupling agent includes one or more of a silane coupling agent, a titanate coupling agent, a zirconium coupling agent, and a magnesium coupling agent.

[0110] In some embodiments of the present invention, the thickening agent includes one or more of gum arabic, pectin, agar, gelatin, alginate, carrageenan, dextrin, polysaccharide derivatives, carboxymethyl cellulose, hydroxyethyl cellulose, propylene glycol alginate, methyl cellulose, sodium starch phosphate, sodium alginate, casein, sodium polyacrylate, polyethylene oxide, and polyvinyl pyrrolidone.

[0111] In some embodiments of the present invention, the filler includes one or more of clay, barium sulfate, calcium carbonate, aluminum hydroxide, talc, kaolin, montmorillonite, bentonite, silica, chitin, titanium dioxide, cellulose, and pregelatinized starch.

[0112] Furthermore, the present invention provides a method for preparing the polyhydroxyalkanoate composition.

[0113] The preparation method provided by the present invention includes the step of mixing the PHA terpolymer with other components. It is understood that when the polyhydroxyalkanoate contains only one PHA terpolymer and does not include other components such as additives, no mixing is required.

[0114] In some embodiments of the present invention, the PHA terpolymer is obtained by fermentation culture of recombinant bacteria.

[0115] Specifically, the preparation of the terpolymer P3HB4HB3HV may refer to the applicant's prior application CN114134096A, and the preparation of the terpolymer P3HB4HB5HV may refer to the applicant's prior application CN113684169A.

[0116] In other embodiments of the present invention, the PHA terpolymer is obtained by recycling and degrading high molecular weight (over 200,000) P3HB4HB3HV or P3HB4HB5HV materials obtained by fermentation and culture of recombinant bacteria. The degradation method can be biological degradation, chemical degradation, or physical degradation.

[0117] Furthermore, the present invention provides an adhesive comprising the polyhydroxyalkanoate composition.

[0118] Adhesive is a substance that can bond two or more materials together and is widely used in the fields of construction, manufacturing, automobiles, aerospace, medical care, etc. According to different classification standards, adhesives can be classified in many ways. For example, according to chemical composition, they can be divided into natural adhesives and synthetic adhesives. Natural adhesives come from nature or through biosynthesis, such as starch, rubber, etc.; synthetic adhesives are made through chemical synthesis, such as polymers, resins, etc. The adhesives described in the present invention are classified as natural adhesives. According to morphological classification, they can be divided into three types: liquid adhesives, solid adhesives and paste adhesives. Liquid adhesives are mostly solvent-based or aqueous solution-based; solid adhesives are mostly in the form of powder, rods, sheets, etc.; paste adhesives are mostly in the form of pastes or emulsions. The adhesives described in the present invention are mainly liquid and paste-based.

[0119] The adhesive of the present invention includes but is not limited to water-based glue, self-adhesive glue, solid glue, sealant, etc.

[0120] Furthermore, the present invention provides a dressing comprising the polyhydroxyalkanoate composition.

[0121] Dressings are materials used to cover and protect wounds and are commonly used in the medical field. The primary function of a dressing is to promote wound healing while also protecting the wound from environmental damage. The dressings described herein include, but are not limited to, tourniquets, medical adhesive tapes, and Band-Aids. The polyhydroxyalkanoate composition can be used as the adhesive for tourniquets, medical adhesive tapes, and Band-Aids.

[0122] Furthermore, the present invention provides a coating or pigment comprising the polyhydroxyalkanoate composition.

[0123] Paint is a material applied to the surface of an object being protected or decorated, forming a thin, continuous film that adheres firmly to the object. It is a viscous liquid primarily composed of resins, oils, and emulsions, with or without pigments (substances that impart color), fillers, and appropriate additives, formulated with organic solvents or water. The coatings described herein include water-based paints (for walls, paper, and metal), oil-based paints, neutral paints, and water-based lacquers.

[0124] The pigment of the present invention refers to a viscous liquid obtained by adding a substance that can dye an object into a color to a coating. The pigment of the present invention includes water-based pigments, oil-based pigments, neutral pigments, etc.

[0125] In a sixth aspect, the present invention provides an ink comprising the polyhydroxyalkanoate composition.

[0126] Ink is an important printing material used for printing various substrates, such as paper, cloth, and metal. It is composed of a homogeneous mixture of pigments, binders, fillers, and additives. Ink has a wide range of applications, including in printing books, packaging, and architectural decoration. As social demand increases, the variety and production of inks are also expanding and growing accordingly. The inks described herein include, but are not limited to, printing inks, writing inks, and printing inks.

[0127] The present invention provides a polyhydroxyalkanoate composition, a preparation method, and an application thereof. The polyhydroxyalkanoate composition comprises P3HB4HB3HV and / or P3HB4HB5HV, wherein the molar content of 3HB is less than 94%, the molar content ratio of 4HB to 3HV or 5HV is greater than 4.2, and the weight-average molecular weight is between 8,000 and 200,000. Therefore, the obtained polyhydroxyalkanoate composition can meet the requirements of being marine degradable, having high peel strength, and having pressure-sensitive curing properties, thereby obtaining an environmentally friendly, low-carbon, and high-performance adhesive, dressing, coating, pigment, ink, or the like. DETAILED DESCRIPTION

[0128] The term "include" or "comprising" in the present invention is an open description containing the specified components or steps described, as well as other specified components or steps that do not substantially affect them.

[0129] The endpoints of the ranges and any values ​​disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoints of each range, the endpoints of each range and individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered to be specifically disclosed herein.

[0130] In the description of this specification, the reference terms "one embodiment", "some embodiments", "specific implementation methods", or "some specific implementation methods" and the like mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiments of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0131] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention are described clearly and completely below. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0132] If no specific techniques or conditions are specified in the examples, the experiments were carried out according to the techniques or conditions described in the literature in the field or according to the product instructions. If no manufacturer is specified for the reagents or instruments used, they are all conventional products that can be purchased through regular channels.

[0133] The English abbreviations that appear in this article correspond to the following Chinese full names:

[0134] PHA: polyhydroxyalkanoate

[0135] PHB: Poly-3-hydroxybutyrate

[0136] PHBV: poly(3-hydroxybutyrate-co-3-hydroxyvalerate)

[0137] P3HB4HB or P34HB: poly(3-hydroxybutyrate-co-4-hydroxybutyrate)

[0138] PHBHHx: poly(3-hydroxybutyrate-co-3-hydroxyhexanoate)

[0139] P3HB5HV: poly(3-hydroxybutyrate-co-5-hydroxyvalerate)

[0140] P3HB4HB3HV: poly(3-hydroxybutyrate-co-4-hydroxybutyrate-co-3-hydroxyvalerate)

[0141] P3HB4HB5HV: poly(3-hydroxybutyrate-co-4-hydroxybutyrate-co-5-hydroxyvalerate).

[0142] P3HB4HB3HHx: poly(3-hydroxybutyrate-co-4-hydroxybutyrate-co-3-hydroxyhexanoate).

[0143] In the following examples, the load deformation temperature of the polyhydroxyalkanoate pellets was tested according to GB / T 1634.2; and the tensile strength and elongation at break of the polyhydroxyalkanoate pellets were tested according to GB / T 1040.2.

[0144] In the following examples, the melting point and crystallinity are those of the corresponding PHA terpolymers in each example and comparative example; the light transmittance and haze of the polyhydroxyalkanoate pellets were tested according to Method A of GB / T2410.

[0145] In the following examples, the peel strength of the polyhydroxyalkanoate composition was tested according to GB / T 2791 standard.

[0146] Antibacterial test: refer to GB / T 24253-2009 Evaluation of antibacterial properties of textiles Part 2: Absorption method. The sample is coated with the polyhydroxyalkanoate composition of the corresponding example on 110g / m 2 Made on woven fabric, the coating amount is 20g / m 2 .

[0147] In the following examples, the preparation method of the polyhydroxyalkanoate composition includes:

[0148] One or more PHA terpolymers (and additives, other types of PHA) are weighed according to a set mass ratio, and then dispersed or mixed using a high-speed disperser, physical stirring, homogenization, ultrasound or surface chemical modification to obtain a polyhydroxyalkanoate composition.

[0149] Example 1

[0150] 99 parts by mass of P3HB4HB3HV (weight-average molecular weight of 960,000, 3HB molar content of 97%, 4HB molar content of 1.5%, 3HV molar content of 1.5%, crystallinity of 52.6%, melting point of 149°C) and 1 part of pentaerythritol were blended with a high-speed mixer at room temperature at a speed of 300 r / min for 1 minute. The mixture was fed into the feed port of a screw extruder. The processing temperature was set within the range of 120-150°C, the main engine speed was 120-180 r / min, and the feed rate or production capacity was adjusted according to the actual production status. The pellets, i.e., polyhydroxyalkanoate pellets, were prepared by a strand cutting method.

[0151] Polyhydroxyalkanoate pellets were fed into the injection molding machine feed port. The injection molding parameters were set to 148°C in zone 1, 144°C in zone 2, and 140°C in zone 3 (mold opening). The mold closing time was 2s, the mold opening time was 1s, the holding time was 5s, the injection delay was 2s, the cooling time was 10s, the cycle time was 10s, and the screw exit delay was 0s to obtain the injection molded product.

[0152] Example 2-12

[0153] The polyhydroxyalkanoate pellets of Examples 2 to 12 were prepared in the same manner as in Example 1, wherein the polyhydroxyalkanoate composition ratios are shown in Tables 1 and 2, and the properties of the resulting pellets are shown in Tables 1 and 2. At the same time, various existing molding methods were used to prepare different products (molded bodies), as shown in Tables 1 and 2 for details.

[0154] Table 1

[0155] Table 2 Note: The dosage of additives in the above table is based on the total mass of the composition.

[0156] Comparative Examples 1-4

[0157] Polyhydroxyalkanoate pellets for Comparative Examples 1 to 4 were prepared using the same method as Example 1. The polyhydroxyalkanoate composition ratios and properties of the resulting pellets are shown in Table 3. Various products (molded bodies) were also produced using various existing molding methods, as detailed in Table 3. Compared with Example 11, the molar content of 3HB in Comparative Example 1 was lower, while the contents of 4HB and 5HV were higher; the molecular weight in Comparative Example 2 was lower; 5HV in Comparative Example 3 was replaced with 3HHx; and both 4HB and 5HV in Comparative Example 4 were replaced with 3HV.

[0158] Table 3

[0159] From the above results, it can be seen that P3HB4HB3HV and P3HB4HB5HV with a 3HB molar content of more than 94% and a weight-average molecular weight of more than 300,000 have good performance. Therefore, the polyhydroxyalkanoate composition containing them can meet the requirements of marine degradability, high strength, high crystallinity and low melting point, and obtain environmentally friendly, low-carbon and good-performance products.

[0160] Example 13

[0161] 99 parts by mass of P3HB4HB3HV (weight-average molecular weight of 780,000, 3HB molar content of 93%, 4HB molar content of 1%, 3HV molar content of 6%, crystallinity of 39.5%, melting point of 137°C) and 1 part of isosorbide were blended with a high-speed mixer at room temperature at a speed of 300 r / min for 30 seconds. The above mixture was fed into the feed port of a screw extruder. The processing temperature was set within the range of 60-140°C, the main engine speed was 120-200 r / min, and the feed rate or production capacity was adjusted according to the actual production status. The pellets, i.e., polyhydroxyalkanoate pellets, were prepared by strand cutting.

[0162] The polyhydroxyalkanoate pellets are placed in a mold and hot-pressed in a flat-plate vulcanizer at a temperature of 135-175° C., a time of 2-5 minutes, and a pressure of 10-15 kPa. The mold is then cooled and demolded to obtain a sheet product.

[0163] Examples 14-22

[0164] The polyhydroxyalkanoate pellets of Examples 14 to 22 were prepared in the same manner as in Example 13, wherein the polyhydroxyalkanoate composition ratios are shown in Tables 4 to 6, and the properties of the resulting pellets are shown in Tables 4 to 6. At the same time, various existing molding methods were used to prepare different products (molded bodies), as shown in Tables 4 to 6 for details.

[0165] Compared with Example 13, Example 21 has another type of PHA terpolymer component, and Example 22 has another type of PHA component.

[0166] Comparative Examples 5-11

[0167] Polyhydroxyalkanoate pellets of Comparative Examples 5-11 were prepared using the same method as Example 13, wherein the polyhydroxyalkanoate composition formulations are shown in Tables 5 and 6, and the properties of the resulting pellets are shown in Tables 5 and 6. Various existing molding methods were also used to produce different products (molded bodies), as detailed in Tables 5 and 6. Compared with Example 20, the molar content of 3HB in Comparative Example 5 was too high; compared with Example 16, the molar ratio of 4HB to 5HV in Comparative Example 6 was greater than 0.16, the molecular weight in Comparative Example 7 was too low, and 3HV in Comparative Example 8 was replaced with 3HHx; compared with Example 15, both 4HB and 5HV in Comparative Example 9 were 5HV; and compared with Example 22, the content of other types of PHA in Comparative Examples 10 and 11 was too high.

[0168] Table 4

[0169] Table 5

[0170] Table 6 Note: The dosage of additives and other types of PHA in the above table are based on the total mass of the composition, and the remainder is the content of the PHA terpolymer.

[0171] From the above results, it can be seen that P3HB4HB3HV and P3HB4HB5HV, whose 3HB molar content is less than 94% and whose 4HB to 3HV or 5HV molar content ratio is less than 0.16, have good performance. Therefore, the polyhydroxyalkanoate composition containing them and accounting for more than 70% can meet the requirements of marine degradation, fast crystallization rate and small spherulites, good toughness and high transparency, and obtain environmentally friendly, low-carbon and good performance products.

[0172] Examples 23-29

[0173] Examples 23-29 respectively provide a polyhydroxyalkanoate composition, wherein the composition ratio of each example is shown in Table 1, and the properties of the obtained polyhydroxyalkanoate composition or the PHA terpolymer therein are shown in Table 7. At the same time, the obtained polyhydroxyalkanoate composition is applied to adhesives, dressings, coatings or pigments, inks, etc., as shown in Table 7 for details.

[0174] Table 7 Note: The dosage of additives and other PHA contents in the above table are based on the total mass of the composition, and the remainder is the content of the PHA terpolymer;

[0175] The applied pressure is not the minimum pressure required for the PHA terpolymer of the corresponding embodiment to undergo pressure-sensitive curing, and is for example only.

[0176] Comparative Examples 12-17

[0177] Comparative Examples 12-17 each provide a polyhydroxyalkanoate composition having the formulations shown in Table 8. The properties of the resulting polyhydroxyalkanoate composition or the PHA terpolymer therein are shown in Table 8. Compared with Example 27, the molar content of 3HB in Comparative Example 12 is too high; compared with Example 25, the molar ratio of 4HB to 3HV in Comparative Example 13 is less than 4.2, the molecular weight in Comparative Example 14 is too high, and 3HV in Comparative Example 15 is replaced with 3HHx; compared with Example 24, both 4HB and 5HV in Comparative Example 16 are 5HV; and compared with Example 26, the content of P34HB in Comparative Example 17 is too high.

[0178] Table 8 Note: The dosage of additives and other PHA contents in the above table are based on the total mass of the composition, and the remainder is the content of the PHA terpolymer;

[0179] The applied pressure is not the minimum pressure required for the PHA terpolymer of the corresponding embodiment to undergo pressure-sensitive curing, and is for example only.

[0180] From the above results, it can be seen that the molar content of 3HB is less than 94%, the molar content ratio of 4HB to 3HV or 5HV is above 4.2, and P3HB4HB3HV and P3HB4HB5HV with a weight average molecular weight between 8000 and 200000 have good performance. Therefore, the polyhydroxyalkanoate composition containing them (accounting for more than 70% by mass) can meet the requirements of marine degradation, high peel strength, and pressure-sensitive curing properties, and obtain environmentally friendly, low-carbon and good-performance adhesives, dressings, coatings or pigments, inks, etc.

[0181] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

[0182] Industrial Applicability Description

[0183] The present invention provides a polyhydroxyalkanoate (PHA) composition, its preparation method, and application. The polyhydroxyalkanoate composition includes a PHA terpolymer, wherein the PHA terpolymer is P3HB4HB3HV, P3HB4HB5HV, or a combination thereof. The polyhydroxyalkanoate composition containing the specific PHA terpolymer provided herein can achieve numerous excellent properties, including marine degradability, with minimal or no additives.

Claims

1. A polyhydroxyalkanoate composition, characterized in that: The polyhydroxyalkanoate composition includes a PHA terpolymer, and the PHA terpolymer is P3HB4HB3HV, P3HB4HB5HV, or a combination thereof.

2. The polyhydroxyalkanoate composition according to claim 1, characterized in that The polyhydroxyalkanoate composition comprises a PHA terpolymer, wherein the PHA terpolymer is P3HB4HB3HV and / or P3HB4HB5HV, wherein the molar content of the repeating unit 3HB in the PHA terpolymer is greater than 94%, and the weight average molecular weight of the PHA terpolymer is greater than 300,000.

3. The polyhydroxyalkanoate composition according to claim 2, characterized in that The PHA terpolymer has a crystallinity of 30% to 70% and a melting point below 155°C.

4. The polyhydroxyalkanoate composition according to claim 2 or 3, characterized in that The mass percentage of the PHA terpolymer in the polyhydroxyalkanoate composition is more than 60%.

5. The polyhydroxyalkanoate composition according to claim 2 or 3, characterized in that According to the GB / T 1634.2 test standard, the load deformation temperature of the polyhydroxyalkanoate composition is above 85°C; According to the GB / T 1040.2 test standard, the tensile strength of the polyhydroxyalkanoate composition is greater than 18 MPa, and the elongation at break is greater than 5%.

6. The polyhydroxyalkanoate composition according to claim 1, characterized in that The polyhydroxyalkanoate composition includes a PHA terpolymer, wherein the PHA terpolymer is P3HB4HB3HV and / or P3HB4HB5HV; The molar content of 3HB in the PHA terpolymer is less than 94%, and the molar content ratio of 4HB to 3HV or 5HV is less than 0.16; The weight average molecular weight of the PHA terpolymer is between 200,000 and 2,000,000.

7. The polyhydroxyalkanoate composition according to claim 6, characterized in that The half crystallization time t of the PHA terpolymer at 60°C 1 / 2 Between 10-30s, the crystallization temperature Tc is between 50-85℃.

8. The polyhydroxyalkanoate composition according to claim 6 or 7, characterized in that The mass proportion of the PHA terpolymer in the polyhydroxyalkanoate composition is more than 70%.

9. The polyhydroxyalkanoate composition according to claim 6 or 7, characterized in that According to the GB / T 2410 Method A test standard, for a thickness of 100 μm, the light transmittance of the polyhydroxyalkanoate composition is above 81.5% and the haze is below 8.5%; According to the GB / T 1040.2 test standard, the tensile strength of the polyhydroxyalkanoate composition is greater than 3.5 MPa, and the elongation at break is greater than 25%.

10. The polyhydroxyalkanoate composition according to claim 1, 2, 6 or 7, characterized in that: The polyhydroxyalkanoate composition further comprises an auxiliary agent, wherein the auxiliary agent is selected from one or more of a nucleating agent, a chain extender, an antioxidant, a plasticizer, and a filler; Preferably, based on the mass of the polyhydroxyalkanoate composition, the amount of the nucleating agent added is 0.01-2%, the amount of the chain extender added is 0.1-2%, the amount of the antioxidant added is 0.1-2%, the amount of the plasticizer added is 0.1-2%, and the amount of the filler added is 0.1-30%; Further preferably, the nucleating agent is selected from one or more of hexagonal crystal structure compounds, pyrimidines, purines, dicarboxylic acid salicylic acid hydrazides, melamine, sugar alcohol compounds, fatty acid amides, TMC300 and TMC 306 of Shanxi Chemical Research Institute; And / or, the chain extender is selected from one or more of isocyanates, BASF Joncryl ADR-4400 / ADR-4468, Shanxi Chemical Research Institute KL-E series, Japan Catalyst EPOCROS RPS 1005, 1,3-bis(2-oxazoline)benzene, 2,2'-(1,3-phenylene)-bisoxazoline, and trimethylolpropane chain extender; And / or, the antioxidant is selected from one or more of antioxidant 1010, antioxidant 1076, antioxidant BHT, antioxidant 1098, antioxidant 245, antioxidant 168, antioxidant DSTP, antioxidant 412S, antioxidant DLTP, antioxidant PEPQ, carbodiimide, polymerized carbodiimide, HyMax 1010, TNK-01, KSJ-936, DuPont 132F NC010, German Lasig STABILIZER 7000, Rhein Chemical Stabaxol P, American Doverphos S-9228, and stearate; And / or, the plasticizer is selected from one or more of isosorbide dioctanoate, acetylated ricinoleic acid dimethyl glyceride, epoxy tetrahydrophthalate, castor oil, polyethylene glycol series, polypropylene glycol series, acetyl tributyl citrate, acetyl tributyl citrate, epoxy soybean oil, glycerol, triacetin, fatty acids, and fatty alcohols; And / or, the filler is selected from one or more of clay, calcium carbonate, talc, kaolin, montmorillonite, bentonite, silicon dioxide, chitin, titanium dioxide, cellulose, and pregelatinized starch.

11. The method for preparing the polyhydroxyalkanoate composition according to any one of claims 1 to 10, characterized in that: The method comprises the steps of mixing the PHA terpolymer with other components; Preferably, the PHA terpolymer is obtained by fermentation culture of recombinant bacteria.

12. A PHA powder, characterized in that: A polyhydroxyalkanoate composition comprising any one of claims 1 to 10.

13. A PHA pellet, characterized in that: A polyhydroxyalkanoate composition comprising any one of claims 1 to 10.

14. A PHA molded body, characterized in that: A polyhydroxyalkanoate composition comprising any one of claims 1 to 10.

15. The PHA molded product according to claim 14, characterized in that The PHA molded body is a molded product, an extruded product, a wire drawing product, a fiber product, a 3D printed product, a foamed product, a sheet product or a plate product.

16. The PHA molded product according to claim 14, characterized in that The PHA molded body is a thin product, including but not limited to a plate, a sheet, a film, a strip, and a packaging material.

17. The polyhydroxyalkanoate composition according to claim 1, characterized in that: The polyhydroxyalkanoate composition includes a PHA terpolymer, wherein the PHA terpolymer is P3HB4HB3HV, P3HB4HB5HV or a combination thereof, wherein the molar content of the repeating unit 3HB is less than 94%, the molar content ratio of 4HB to 3HV or 5HV is greater than 4.2, and the weight average molecular weight of the PHA terpolymer is between 8000 and 200000.

18. The polyhydroxyalkanoate composition according to claim 17, characterized in that The half crystallization time t of the PHA terpolymer 1 / 2 Above 1200s; Preferably, the half crystallization time t of the PHA terpolymer measured at 60°C and under a pressure of 50 kPa-2 MPa is 1 / 2 Between 1-300s.

19. The polyhydroxyalkanoate composition according to claim 18 or 17, characterized in that: The polyhydroxyalkanoate composition does not contain crystalline polyhydroxyalkanoate; The mass proportion of the PHA terpolymer in the polyhydroxyalkanoate composition is more than 70%.

20. The polyhydroxyalkanoate composition according to claim 18 or 17, characterized in that: According to the GB / T 1040.2 test standard, the tensile strength of the PHA terpolymer is between 0.12-3.3 MPa, and the elongation at break is not less than 220%; According to the GB / T 2791 test standard, the peel strength of the polyhydroxyalkanoate composition is not less than 0.35 kN / m.

21. The polyhydroxyalkanoate composition according to any one of claims 17 to 20, characterized in that: The polyhydroxyalkanoate composition further comprises an auxiliary agent, wherein the auxiliary agent is selected from one or more of a curing agent, a solvent, a plasticizer, a coupling agent, a thickener, and a filler; Preferably, based on the mass of the polyhydroxyalkanoate composition, the amount of the curing agent added is 0.1-5%, the amount of the solvent added is 1-80%, the amount of the plasticizer added is 0.1-5%, the amount of the coupling agent added is 0.1-2%, the amount of the thickener added is 0.1-2.5%, and the amount of the filler added is 0.1%-8%; Further preferably, the curing agent includes one or more of aliphatic polyamines, alicyclic polyamines, low molecular weight polyamides and modified aromatic amines; And / or, the solvent includes one or more of water, ethanol, ethylene glycol, n-propanol, propylene glycol, glycerol, acetone, isobutanol, 1,4-butanediol, methyl ethyl ketone, isoamyl alcohol, ethyl acetate, propyl acetate, butyl acetate, ethylene glycol diacetate, ethylene glycol dibutyrate, limonene, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, 1-allyl-3-methylimidazolium chloride, 1-ethyl-3-methylimidazolium acetate, tributylmethylammonium bis(trifluoromethylsulfonyl)imide, 1-ethyl-3-methylimidazolium dicyanamide, 1-ethyl-3-methylimidazolium ethyl sulfate, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, and 1-butyl-3-methylimidazolium tetrafluoroborate; And / or, the plasticizer includes one or more of isosorbide dioctanoate, acetylated ricinoleic acid dimethyl glyceride, epoxy tetrahydrophthalate, castor oil, polyethylene glycol series, polypropylene glycol series, acetyl tributyl citrate, acetyl tributyl citrate, epoxy soybean oil, glycerol, triacetin, fatty acid plasticizers, and fatty alcohol plasticizers; And / or, the coupling agent includes one or more of a silane coupling agent, a titanate coupling agent, a zirconium coupling agent, and a magnesium coupling agent; and / or, the thickener comprises one or more of gum arabic, pectin, agar, gelatin, alginate, carrageenan, dextrin, polysaccharide derivatives, carboxymethyl cellulose, hydroxyethyl cellulose, propylene glycol alginate, methyl cellulose, sodium starch phosphate, sodium alginate, casein, sodium polyacrylate, polyethylene oxide, and polyvinyl pyrrolidone; And / or, the filler includes one or more of clay, barium sulfate, calcium carbonate, aluminum hydroxide, talc, kaolin, montmorillonite, bentonite, silicon dioxide, chitin, titanium dioxide, cellulose, and pregelatinized starch.

22. The method for preparing the polyhydroxyalkanoate composition according to any one of claims 17 to 21, characterized in that: The method comprises the steps of mixing the PHA terpolymer with other components; The PHA ternary copolymer is obtained by fermentation and culture of recombinant bacteria, or is obtained by recycling and degrading P3HB4HB3HV or P3HB4HB5HV materials with a molecular weight of more than 200,000 obtained by fermentation and culture of recombinant bacteria.

23. An adhesive, characterized in that: A polyhydroxyalkanoate composition comprising any one of claims 17-21.

24. A dressing, characterized in that A polyhydroxyalkanoate composition comprising any one of claims 17-21.

25. A coating or pigment, characterized in that: A polyhydroxyalkanoate composition comprising any one of claims 17-21.

26. An ink, characterized in that: A polyhydroxyalkanoate composition comprising any one of claims 17-21.

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