A polyhydroxyalkanoate product and a process for its preparation

Abstract

The application discloses a polyhydroxyalkanoate product and a preparation method thereof, and belongs to the technical field of high polymer materials. The polyhydroxyalkanoate product comprises the following components in parts by weight: 30-45 parts of polyhydroxyalkanoate with high crystallinity, 30-45 parts of crystalline polyhydroxyalkanoate, 5-15 parts of amorphous polyhydroxyalkanoate, 0-30 parts of a filler and 0.1-4 parts of an additive. The application combines the characteristics of different types of PHA, such as the high crystallinity and strength of PHB with high crystallinity, and the good processing performance of crystalline P34HB. The amorphous P34HB with low glass transition temperature and good toughness is used as a toughening agent, and the filler and the additive are supplemented, so that the polyhydroxyalkanoate product can be obtained. The biological material has good physical and mechanical properties and processing performance, and significant low-temperature toughness, and meanwhile, the unique marine degradation characteristics of PHA are maintained, and can be used in various application scenarios such as injection molding, film coating, straw, fiber, sheet and the like.

Description

Technical Field

[0001] This invention discloses a polymer material technology, and in particular relates to a polyhydroxyalkanoate product and its preparation method. Background Technology

[0002] Polyhydroxyalkanoates (PHAs) are both a type of "bio-based biodegradable material" and a means of achieving "carbon reduction." Compared to widely used biodegradable materials such as PLA, PBAT, and modified starch, PHAs offer several advantages. First, the diverse molecular properties of PHAs allow for different applications. Second, PHAs can degrade through various pathways, including marine degradation, industrial composting, and household composting, exhibiting more diverse degradation characteristics. Notably, their marine degradation capability is unique among biodegradable materials. Therefore, the development of PHA materials and their applications is currently a hot research topic in the field of degradation.

[0003] PHA has a wide variety of synthetic monomers; according to statistics, more than 150 types of hydroxy fatty acids have been identified as constituents of PHA. PHA products with relatively mature processing technologies and applications mainly include PHB, PHBV, P34HB, and PHBH. PHB is a short-chain homopolymer with 3HB as the monomer, possessing good strength and crystallinity. However, due to its melting point being close to its thermal decomposition temperature, its thermal processing window is very narrow, making processing difficult and resulting in products with significant brittleness. Therefore, it is mainly used for injection molding and fibers. P34HB is a short-chain copolymer, which can be classified as crystalline or amorphous depending on its 4HB content. It has advantages such as high strength, good ductility, controllable mechanical properties, good thermal stability, and excellent processing performance. However, while possessing many advantages, this material also has significant drawbacks; P34HB with a lower 4HB content lacks sufficient toughness and strength. Furthermore, its high cost also limits the widespread application of P34HB to some extent.

[0004] To improve the processing performance of PHA and enhance its toughness and strength, the current common practice is to blend it with other biodegradable materials to achieve better physical and mechanical properties, such as blending it with PLA to improve its toughness and blending it with PBAT to improve its strength. However, since biodegradable materials such as PLA, PBAT, and PBS cannot meet the requirements for marine degradation, although this method effectively improves the performance of PHA, it causes it to lose its unique marine degradation characteristics. Summary of the Invention

[0005] The purpose of this invention is to provide a polyhydroxy fatty acid ester product and its preparation method in order to solve the above-mentioned problems.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a polyhydroxyalkanoate product comprising the following components by weight: 30-45 parts of PHB with a crystallinity of 49-55%, 30-45 parts of crystalline P34HB, 5-15 parts of amorphous P34HB, 0-30 parts of filler and 0.1-4 parts of additives;

[0007] The fillers include barium sulfate, talc, and boron nitride;

[0008] The additives include nucleating agents, antioxidant 1010, antioxidant 168, anti-hydrolysis agent carbodiimide, and food-grade white oil as a lubricant;

[0009] Nucleating agents include erucamide, oleamide, behenamide, lauramide, nano silica, titanium dioxide, and boron nitride.

[0010] By adopting the above technical solution, a polyhydroxyalkanoate product can be configured that can be applied to various scenarios such as injection molding, coating, and pipe stretching.

[0011] Preferably, the molar content of 4HB in PHB with a crystallinity of 49-55% is 5-15%.

[0012] By adopting the above technical solution, PHA is modified with PHB, which not only maintains the unique marine degradation characteristics of PHA, but also improves its product toughness and low-temperature toughness.

[0013] Preferably, the molar content of 4HB in amorphous P34HB is 50-60%.

[0014] By adopting the above technical solution, P34HB is modified to improve the original toughness and strength defects of P34HB, giving polyhydroxyalkanoate products advantages such as high strength, good ductility, controllable mechanical properties, good thermal stability, and excellent processing performance.

[0015] A method for preparing a polyhydroxyalkanoate product, the method comprising the following steps:

[0016] PHB with a crystallinity of 49-55%, crystalline P34HB, amorphous P34HB, fillers and additives are mixed in proportions by weight and extruded and granulated using a twin-screw extruder. The temperature of the twin-screw extruder is controlled at 100-165℃ and the screw speed is 200-300rpm.

[0017] By adopting the above technical solution, the characteristics of different types of PHA, such as the high crystallinity and strength of highly crystalline PHB and the good processing performance of crystalline P34HB, are combined to prepare polyhydroxy fatty acid ester products with good general performance.

[0018] Preferably, the product extruded by the twin-screw extruder is crystallized in a water bath at a water temperature of 55-62℃.

[0019] By adopting the above technical solution and setting the water temperature to 55-62℃, the degree of crystallization can be better controlled.

[0020] Preferably, the crystallized product is processed by post-processing equipment, which includes a control cabinet, a heating zone, and a deodorization zone. The heating zone includes a placement module, a heating component, and a centrifugal fan system. The deodorization zone includes a deodorization module and an air outlet device. The placement module of the heating zone consists of several metal placement frames spliced ​​together, with rollers at the bottom of the placement frames. The heating component and centrifugal fan system are placed on top of the heating zone. The centrifugal fan system provides uniform heating to the heating zone. The hot air generated in the heating zone is guided into the deodorization zone by the air outlet device and treated by adsorption or chemical reaction through the deodorization module in the deodorization zone.

[0021] By adopting the above technical solution, the crystallized product is placed in a placement frame and enters the heating zone; after setting the heating temperature and holding time, the product crystallizes more completely and the structure gradually stabilizes in the heating zone; under the action of hot air, molecules with smaller molecular weights are dispersed and guided to the deodorization zone, and then adsorbed by the deodorization module, ultimately achieving complete crystallization and deodorization effects.

[0022] Compared with the prior art, the beneficial effects of the present invention are:

[0023] Firstly, by combining the characteristics of different types of PHA, such as the high crystallinity and strength of highly crystalline PHB and the good processing performance of crystalline P34HB, a PHA product with good physical and mechanical properties and processing performance can be developed.

[0024] Secondly, amorphous P34HB with low glass transition temperature and good toughness is used as a toughening agent to achieve PHA toughened PHA. This allows the PHA product to maintain its marine degradation characteristics while directly meeting the application requirements of various scenarios such as injection molding, coating, straws, fibers, and sheets, and has wide versatility.

[0025] Thirdly, by using post-processing equipment for temperature control and hot air rinsing, the crystallization process of polyhydroxyalkanoate (PHA) products tends to be complete and releases low molecular weight components with strong odors. Under the guidance of the gas outlet device, the odor flows unidirectionally from the heating zone to the deodorization zone, where it is adsorbed and treated by the deodorization module. This not only solves the problem of unstable product structure and performance caused by PHA post-crystallization, but also greatly reduces the unique grain fermentation odor of PHA, expanding its application in the field of biodegradability. Attached Figure Description

[0026] Figure 1This is a schematic diagram of the post-processing equipment.

[0027] Attached reference numerals: 1. Control cabinet; 2. Heating zone; 3. Deodorizing zone; 4. Placement module; 5. Centrifugal fan system; 6. Deodorizing module; 7. Air outlet device. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. In this description, it should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0029] The full Chinese translations of the English abbreviations used in this article are as follows:

[0030] PHA: Polyhydroxy fatty acid ester;

[0031] PBAT: Polybutylene adipate / terephthalate;

[0032] PLA: Polylactic acid;

[0033] PHB: Poly-3-hydroxybutyrate;

[0034] PHBV: Poly(3-hydroxybutyrate-co-3-hydroxyvalerate);

[0035] P34HB: Poly(3-hydroxybutyrate-co-4-hydroxybutyrate);

[0036] This invention includes the following four embodiments, and the Vicat softening point is tested according to GB / T1633-2000 "Determination of Vicat softening temperature (VST) of thermoplastic plastics", the flexural modulus is tested according to GB / T9341-2008 "Determination of flexural properties of plastics", the impact strength is tested according to GB / T1043.2-2008 "Determination of impact strength of simply supported beams of plastics", and the tensile strength is tested according to GB / T1040.1-2008 "Determination of tensile strength of plastics".

[0037] Example 1

[0038] A polyhydroxyalkanoate product, by weight, comprises the following components:

[0039] PHB (Beijing Microstructure PB3000, 4HB content 15%, crystallinity 55%), 32 parts by weight;

[0040] P34HB (MDF150, 4HB content 5%, crystallinity 60%), 32 parts by weight;

[0041] Amorphous P34HB (Korean CJA1000P, 4HB content 50%), 14 parts by weight;

[0042] Filler: 13 parts by weight of talc, 5 parts by weight of barium sulfate, and 3 parts by weight of boron nitride;

[0043] Nucleating agent: Erucamide, 0.1 parts by weight;

[0044] Anti-hydrolysis agent: carbodiimide, 0.1 parts by weight;

[0045] Lubricant: Food-grade white oil, 0.2 parts by weight;

[0046] Antioxidants: Antioxidant 1010, 0.1 parts by weight; Antioxidant 168, 0.15 parts by weight;

[0047] The preparation method is as follows: Weigh each component according to the mass ratio, mix them for 20 minutes at 1500 rpm using a high-speed mixer, and then extrude and granulate them through a parallel twin-screw extruder at a set heating temperature of 100-165℃, a screw length-to-diameter ratio of 52:1, and a screw speed of 250 rpm. After that, the extruded product is crystallized in a water bath at a water temperature of 58℃ to obtain the polyhydroxy fatty acid ester product.

[0048] The post-processing of polyhydroxyalkanoate products is as follows:

[0049] The obtained polyhydroxy fatty acid ester product is placed in heating zone 2, the temperature is set to 55°C, and the heat preservation time is 10h. In this embodiment, the deodorization module 6 is composed of activated carbon and nanofiber filter membrane.

[0050] The performance test results of the polyhydroxyalkanoate product in this embodiment are shown in Table 1 below:

[0051] Table 1

[0052]

[0053] Example 2

[0054] A polyhydroxyalkanoate product, by weight, comprises the following components:

[0055] PHB (PB3000, 4HB content 15%, crystallinity 55%), 42.5 parts by weight;

[0056] P34HB (MDF150, 4HB content 5%, crystallinity 60%), 42.5 parts by weight;

[0057] Amorphous P34HB (A1000P, 4HB content 50%), 14 parts by weight;

[0058] Nucleating agent: Erucamide, 0.1 parts by weight;

[0059] Anti-hydrolysis agent: carbodiimide, 0.1 parts by weight;

[0060] Lubricant: Food-grade white oil, 0.2 parts by weight;

[0061] Antioxidants: Antioxidant 1010, 0.1 parts by weight; Antioxidant 168, 0.15 parts by weight;

[0062] The preparation method is as follows: Weigh each component according to the mass ratio, mix them for 25 minutes at 1500 rpm using a high-speed mixer, and then extrude and granulate them through a parallel twin-screw extruder at a set heating temperature of 100-165℃, a screw length-to-diameter ratio of 52:1, and a screw speed of 250 rpm. After that, the extruded product is crystallized in a water bath at a water temperature of 58℃ to obtain the polyhydroxy fatty acid ester product.

[0063] The post-processing of polyhydroxyalkanoate products is as follows:

[0064] The obtained polyhydroxy fatty acid ester product is placed in heating zone 2, the temperature is set to 60°C, and the heat preservation time is 8 hours. In this embodiment, the deodorization module 6 is composed of activated carbon and nanofiber filter membrane.

[0065] The performance test results of the polyhydroxyalkanoate product in this embodiment are shown in Table 2 below:

[0066] Table 2

[0067]

[0068] Example 3

[0069] A polyhydroxyalkanoate product, by weight, comprises the following components:

[0070] PHB (Beijing Microstructure PB3000, 4HB content 15%, crystallinity 55%), 32 parts by weight;

[0071] P34HB (MDF150, 4HB content 5%, crystallinity 60%), 32 parts by weight;

[0072] Amorphous P34HB (Korean CJA1000P, 4HB content 50%), 9 parts by weight;

[0073] Filler: 20 parts by weight of talc, 5 parts by weight of barium sulfate, and 3 parts by weight of boron nitride;

[0074] Nucleating agent: Erucamide, 0.1 parts by weight;

[0075] Anti-hydrolysis agent: carbodiimide, 0.1 parts by weight;

[0076] Lubricant: Food-grade white oil, 0.2 parts by weight;

[0077] Antioxidants: Antioxidant 1010, 0.1 parts by weight; Antioxidant 168, 0.15 parts by weight;

[0078] The preparation method is as follows: Weigh each component according to the mass ratio, mix them for 20 minutes at 1500 rpm using a high-speed mixer, and then extrude and granulate them through a parallel twin-screw extruder at a set heating temperature of 100-165℃, a screw length-to-diameter ratio of 52:1, and a screw speed of 270 rpm. After that, the extruded product is crystallized in a water bath at a water temperature of 55℃ to obtain the polyhydroxy fatty acid ester product.

[0079] The post-processing of polyhydroxyalkanoate products is as follows:

[0080] The obtained polyhydroxy fatty acid ester product is placed in heating zone 2, the temperature is set to 55°C, and the heat preservation time is 10h. In this embodiment, the deodorization module 6 is composed of activated carbon and nanofiber filter membrane.

[0081] The performance test results of the polyhydroxyalkanoate product in this embodiment are shown in Table 3 below:

[0082] Table 3

[0083]

[0084] Example 4

[0085] A polyhydroxyalkanoate product, by weight, comprises the following components:

[0086] PHB (MDF150, 4HB content 5%, crystallinity 49%), 40 parts by weight;

[0087] P34HB (MDF200, 4HB content 10%, crystallinity 60%), 40 parts by weight;

[0088] Amorphous P34HB (Korean CJA1000P, 4HB content 50%), 8 parts by weight;

[0089] Filler: 12 parts by weight of talc powder;

[0090] Nucleating agent: Erucamide, 0.1 parts by weight;

[0091] Anti-hydrolysis agent: carbodiimide, 0.1 parts by weight;

[0092] Lubricant: Food-grade white oil, 0.2 parts by weight;

[0093] Antioxidants: Antioxidant 1010, 0.1 parts by weight; Antioxidant 168, 0.15 parts by weight;

[0094] The preparation method is as follows: Weigh each component according to the mass ratio, mix them for 20 minutes at 1500 rpm using a high-speed mixer, and then extrude and granulate them through a parallel twin-screw extruder at a set heating temperature of 100-165℃, a screw length-to-diameter ratio of 52:1, and a screw speed of 250 rpm. After that, the extruded product is crystallized in a water bath at a water temperature of 60℃ to obtain the polyhydroxy fatty acid ester product.

[0095] The post-processing of polyhydroxyalkanoate products is as follows:

[0096] The obtained polyhydroxy fatty acid ester product is placed in heating zone 2, the temperature is set to 65°C, and the heat preservation time is 6 hours. In this embodiment, the deodorization module 6 is composed of activated carbon and nanofiber filter membrane.

[0097] The performance test results of the polyhydroxyalkanoate product in this embodiment are shown in Table 4 below:

[0098] Table 4

[0099]

[0100] The polyhydroxyalkanoate product prepared in Example 1 was injection molded using an extrusion process to obtain standard samples for testing tensile and flexural properties. The standard samples were then divided into two groups: one group received no post-treatment, and the other group received post-treatment, and their properties were compared. The post-treatment conditions were as follows: temperature 55°C, holding time 10 hours, and activated carbon particles as the adsorption medium.

[0101] Performance tests were conducted before and after post-processing, and the results are shown in Table 5.

[0102] Table 5

[0103]

[0104] Post-processing equipment such as Figure 1As shown, the system includes a control cabinet 1, a heating zone 2, and a deodorizing zone 3. The heating zone 2 includes a placement module 4, a heating element, and a centrifugal fan system 5. The deodorizing zone 3 includes a deodorizing module 6 and an air outlet device 7. The placement module 4 of the heating zone 2 consists of several metal placement frames assembled together, with rollers at the bottom of the frames. The heating element and centrifugal fan system 5 are placed on top of the heating zone 2. The centrifugal fan system 5 provides uniform heating to the heating zone 2. The hot air generated in the heating zone 2 is guided into the deodorizing zone 3 by the air outlet device 7 and treated by the deodorizing module 6 of the deodorizing zone 3 through adsorption or chemical reaction. The heating zone 2 is equipped with a control cabinet 1, a heating zone 2, and a deodorizing zone 3 ... With uniform pores, the hot air generated in heating zone 2 continuously blows hot air onto the polyhydroxyalkanoate product through the pores. Guided by the air outlet device in deodorizing zone 3, the air flows continuously in one direction from heating zone 2 to deodorizing zone 3. The relatively small molecular weight components with strong odors are effectively dispersed and fully absorbed by deodorizing module 6, improving the deodorization effect. Deodorizing module 6 is composed of one or more of the following: inorganic adsorbent activated carbon, molecular sieve or activated alumina and nanofiber porous membrane, which further improves the adsorption and reaction treatment of dispersed components, preventing them from dispersing into the air or flowing back into the polyhydroxyalkanoate product.

[0105] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0106] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for preparing a polyhydroxyalkanoate product, characterized in that, The preparation method includes the following steps: PHB with a crystallinity of 49-55%, crystalline P34HB, amorphous P34HB, fillers and additives are mixed in proportion by weight and extruded and granulated through a twin-screw extruder. The temperature of the twin-screw extruder is controlled at 100-165℃ and the screw speed is 200-300rpm. The composition, by weight, is 30-45 parts of PHB with a crystallinity of 49-55%, 30-45 parts of crystalline P34HB, 5-15 parts of amorphous P34HB, 0-30 parts of filler, and 0.1-4 parts of additives. The filler includes barium sulfate, talc, and boron nitride; the additives include nucleating agents, antioxidant 1010, antioxidant 168, anti-hydrolysis agent carbodiimide, and food-grade white oil as a lubricant; the nucleating agents include erucamide, oleamide, behenamide, laurylamide, nano silica, titanium dioxide, and boron nitride. The product extruded by the twin-screw extruder is crystallized in a water bath at a water temperature of 55-62℃. The crystallized product is processed by post-processing equipment, which includes a control cabinet (1), a heating zone (2) and a deodorizing zone (3). The heating zone (2) includes a placement module (4), a heating component and a centrifugal fan system (5). The deodorizing zone (3) includes a deodorizing module (6) and an air outlet device (7). The placement module (4) of the heating zone (2) consists of several metal placement frames spliced ​​together. The bottom of the placement frame is equipped with rollers. The heating component and centrifugal fan system (5) are placed on top of the heating zone (2). The centrifugal fan system (5) provides uniform heating to the heating zone. The hot air generated in the heating zone is guided into the deodorizing zone (3) through the air outlet device (7) and is treated by adsorption or chemical reaction through the deodorizing module (6) of the deodorizing zone (3).

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