Carrier material for improving high-temperature processing resistance of biological enzymes and application thereof

Abstract

The application discloses a carrier material for improving high-temperature processing resistance of biological enzymes and application thereof. The carrier material comprises the following raw materials in mass fraction: 11-31 parts of high-temperature-resistant protective agents with a core-shell structure, 100 parts of porous materials, 1-3 parts of activators and 1-5 parts of surface modifiers. The carrier material can not only play a high-temperature-resistant protection role on biological enzymes in the high-temperature processing process, significantly improve the high-temperature resistance of the biological enzymes, thereby improving the activity of the biological enzymes after high-temperature processing, but also can activate and improve the catalytic activity of the biological enzymes through the activators in the degradation process, so as to jointly promote the biological enzyme catalytic high-molecular material degradation reaction, and provide guidance significance for subsequent preparation of the degradable high-molecular material containing the biological enzymes under the high-temperature processing condition.

Description

Technical Field

[0001] This invention relates to the field of enzyme processing technology. More specifically, it relates to a carrier material for improving the high-temperature processing resistance of biological enzymes and its application. Background Technology

[0002] Bioenzymes are derived from animals (pancreas, stomach), plants (oats, wheat), and microorganisms (bacteria or fungi). They are non-toxic, environmentally friendly biocatalysts with characteristics such as high efficiency, specificity, low consumption, and low reaction conditions. They are currently widely used in textiles, petroleum, food, papermaking and other fields.

[0003] The specificity of biological enzymes is reflected in the fact that one enzyme can only catalyze the chemical reactions of one type of substance. For example, α-amylase can cleave the α-1,4 glycosidic bonds in the long chain of starch molecules, accelerating starch hydrolysis; proteases can cleave the long peptide chains of proteins, breaking them down into short peptides of polysaccharides, ultimately forming water-soluble amino acid molecules; lipases can act on glycerol ester bonds, hydrolyzing them into glycerol and fatty acids. Similarly, it is precisely because extracellular enzymes secreted by microorganisms catalyze and accelerate the early hydrolysis process of biodegradable plastics during biodegradation that starch mixtures and biodegradable polyesters and other biodegradable plastics can be rapidly assimilated / mineralized in the later stages, ultimately achieving complete degradation. This suggests that adding bio-enzymes that catalyze the breaking of polymer chains to polymeric materials that do not degrade or degrade slowly in the natural environment, such as polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyamide (PA), and biodegradable polyesters polylactic acid (PLA) and polybutylene adipate / terephthalate (PBAT), should accelerate the degradation of polymeric materials in the natural environment.

[0004] Unlike conventional catalysts that require harsh conditions such as high temperature, high pressure, strong acids, and strong alkalis, bioenzymes can efficiently catalyze reactions under relatively mild conditions of room temperature and pressure. Therefore, the catalytic conditions required by bioenzymes are generally met in the natural environment. However, it is worth noting that the vast majority of bioenzymes are chemically proteins, and an important property of enzyme proteins is that they denature and lose their catalytic activity when heated. Therefore, preventing bioenzymes from being rapidly destroyed and losing their catalytic activity during the high-temperature processing of polymer materials is a challenging technical problem. Summary of the Invention

[0005] To overcome the above problems, the first objective of this invention is to provide a high-temperature resistant protective agent with a core-shell structure. This high-temperature resistant protective agent achieves thermal insulation protection for the processing of biological enzymes by encapsulating them within a shell structure. Simultaneously, with the introduction of a water-retaining agent in the core region, some heat can be carried away through water evaporation during high-temperature processing, thereby further reducing the probability of the biological enzymes being destroyed by high temperatures.

[0006] A second objective of this invention is to provide a method for preparing the high-temperature resistant protective agent as described above.

[0007] A third objective of this invention is to provide a carrier material containing the heat-resistant protective agent described above, which improves the heat-resistant processability of biological enzymes. This carrier material not only contains the aforementioned heat-resistant protective agent, but also incorporates a porous material with a high-density porous structure and excellent heat-resistant properties, further protecting the structure of the biological enzyme. Additionally, an activator is added to effectively enhance the catalytic activity of the biological enzyme.

[0008] A fourth objective of this invention is to provide the application of the carrier material described above in the preparation of biodegradable polymer products. When this carrier material and the polymer material are subjected to high-temperature heating treatment to obtain biodegradable polymer products, the excellent catalytic effect of the bio-enzyme is still maintained, and the degradation effect is significant.

[0009] To achieve the first objective mentioned above, the present invention adopts the following technical solution:

[0010] This invention discloses a high-temperature resistant protective agent with a core-shell structure, comprising a core material and a shell material. The core material is a biological enzyme and a water-retaining agent, and the shell material is a composite layer of polyvinyl alcohol and an adsorbent-dispersant coating the core material.

[0011] In this invention, the inventors first proposed a high-temperature resistant protective agent with a core-shell structure. A core composed of a biological enzyme and a water-retaining agent is encapsulated in a shell of polyvinyl alcohol (PVA) – an adsorbent-dispersant – achieving high-temperature protection for the biological enzyme, preventing structural damage during high-temperature processing and increasing its activity after processing. Then, using this high-temperature resistant protective agent as a raw material, a carrier material is prepared by compounding it with porous materials, activators, and surface modifiers to improve the high-temperature processability of the biological enzyme. This further protects the enzyme structure while activating its catalytic performance. Finally, during the degradation of the polymer material, the encapsulated biological enzyme is released after water molecules break down the PVA film, promoting the degradation process of the plastic product.

[0012] It should also be noted that the high-temperature protective agent has a typical core-shell structure, with a mixture of biological enzymes and a water-retaining agent forming the core, and polyvinyl alcohol and an adsorbent-dispersant forming the shell material. In this structure, the polyvinyl alcohol in the shell is a water-soluble material that, after dissolving in water, has adhesive properties and can form a protective film on the outside of the core, which serves as the high-temperature protective agent. Simultaneously, water molecules in the polyvinyl alcohol aqueous solution can combine with the water-retaining agent; during high-temperature processing, some of the water evaporates, carrying away some heat and thus reducing the damage to the biological enzymes caused by high temperatures. Therefore, the water-retaining agent in the core and the polyvinyl alcohol in the shell have a synergistic effect. Furthermore, because the surface of the core is coated with a polyvinyl alcohol film, it has a certain lubricating function, which is more conducive to adsorption into the porous structure of the adsorbent-dispersant. The adsorbent-dispersant plays a good adsorption and dispersion role, and due to its excellent thermal stability, it protects the biological enzymes during high-temperature processing.

[0013] The mass ratio of the bio-enzyme, polyvinyl alcohol, water-retaining agent, and adsorption dispersant is 1:5-15:1-3:4-12.

[0014] Furthermore, the bioenzyme is a specific bioenzyme of the selected polymer material, used to accelerate the catalytic breaking of polymer chains. Those skilled in the art can adjust the types of bioenzymes and polymer materials according to actual needs.

[0015] Furthermore, the polyvinyl alcohol has adhesive properties when dissolved in water, which can encapsulate the core of the high-temperature protective agent to form a protective film. The polyvinyl alcohol includes, but is not limited to, one or more of polyvinyl alcohol 0388, polyvinyl alcohol 0588, and polyvinyl alcohol 1788. It should be noted that polyvinyl alcohol 0388, polyvinyl alcohol 0588, and polyvinyl alcohol 1788 are different grades of polyvinyl alcohol.

[0016] Furthermore, the water-retaining agent can combine with biological enzymes to form a core, and the water-retaining agent absorbs some of the water in polyvinyl alcohol, thus removing some heat from the core area during high-temperature processing; including but not limited to one or more of polyacrylamide, sodium polyacrylate, potassium polyacrylate, and ammonium polyacrylate.

[0017] Furthermore, the adsorbent dispersant in the formulation mainly provides good adsorption and dispersion, preventing local overheating. The adsorbent dispersant is diatomaceous earth, which has a high-density porous structure, excellent adsorption properties, and thermal stability. Preferably, the particle size of the adsorbent dispersant is 2500-3000 mesh.

[0018] Furthermore, the mass ratio of the bio-enzyme, polyvinyl alcohol 0388, polyacrylamide, and diatomaceous earth is 1:5-15:1-3:4-12; exemplaryly, the mass ratio of the bio-enzyme, polyvinyl alcohol 0388, polyacrylamide, and diatomaceous earth can also be 1:5-10:1-3:4-12, 1:5-15:1:4-12, 1:5-15:1-3:4-8, 1:5-10:1:4-12, 1:5-10:1-3:4-8, or 1:5-15:1:4-8, etc.; wherein the bio-enzyme can be proteinase K, lipase, or other bio-enzymes.

[0019] Furthermore, the mass ratio of the bio-enzyme, polyvinyl alcohol 0588, sodium polyacrylate, and diatomaceous earth is 1:5-15:1-3:4-12; exemplaryly, the mass ratio of the bio-enzyme, polyvinyl alcohol 0588, sodium polyacrylate, and diatomaceous earth can also be 1:5-10:1-3:4-12, 1:5-15:1:4-12, 1:5-15:1-3:4-8, 1:5-10:1:4-12, 1:5-10:1-3:4-8, or 1:5-15:1:4-8, etc.; wherein the bio-enzyme can be proteinase K, lipase, or other bio-enzymes.

[0020] Furthermore, the mass ratio of the bio-enzyme, polyvinyl alcohol 1788, ammonium polyacrylate, and diatomaceous earth is 1:5-15:1-3:4-12; exemplaryly, the mass ratio of the bio-enzyme, polyvinyl alcohol 1788, ammonium polyacrylate, and diatomaceous earth can also be 1:5-10:1-3:4-12, 1:5-15:1:4-12, 1:5-15:1-3:4-8, 1:5-10:1:4-12, 1:5-10:1-3:4-8, or 1:5-15:1:4-8, etc.; wherein the bio-enzyme can be proteinase K, lipase, or other bio-enzymes.

[0021] To achieve the second objective mentioned above, this invention discloses a method for preparing the above-mentioned high-temperature resistant protective agent, comprising the following steps:

[0022] S1. Mix the biological enzyme and water-retaining agent evenly to obtain the core of the high-temperature resistant protective agent;

[0023] S2. Dissolve polyvinyl alcohol in deionized water, then add the core prepared in step 1 at 45-55℃, stir evenly, place in a vacuum oven for dehydration until viscous, and then add the adsorption dispersant evenly to obtain a high-temperature resistant protective agent with a core-shell structure.

[0024] In step 2, it should be noted that the core is added at a temperature of 45-55℃ to avoid damaging the structure of the biological enzyme and to ensure that the polyvinyl alcohol solution has good fluidity, so that the core is fully wrapped by polyvinyl alcohol and a dense polyvinyl alcohol film is formed on the outer layer of the core. When the core is vacuum dehydrated to a viscous state, the adsorbent dispersant is added so that the adsorbent dispersant can fully adsorb the core wrapped with a certain degree of lubricity of polyvinyl alcohol film, and the adsorbent dispersant is well dispersed, reducing agglomeration.

[0025] To achieve the third objective mentioned above, the present invention adopts the following technical solution:

[0026] This invention discloses a carrier material that can improve the high-temperature processability of biological enzymes, comprising, by mass parts, 11-31 parts of the high-temperature protective agent as described above, 100 parts of porous material, 1-3 parts of activator and 1-5 parts of surface modifier.

[0027] With the proper combination of the above raw materials, this carrier material can be used in the high-temperature processing of polymer materials containing bio-enzymes. This not only prevents the bio-enzymes from being quickly destroyed and losing their catalytic activity during high-temperature processing, thus increasing the activity level after high-temperature processing, but also allows it to be well dispersed in the polymer matrix and has good compatibility with the matrix. Finally, during the degradation process, the encapsulated bio-enzymes can be released after water molecules destroy the polyvinyl alcohol film, exhibiting even more efficient catalytic activity under the action of the activator.

[0028] Furthermore, the porous material is a commonly available commercially available powder material with a porous structure. The raw materials are readily available and stable under high-temperature conditions, including but not limited to one or more of zeolite powder, sepiolite powder, vermiculite powder, perlite powder, gypsum powder, and montmorillonite powder. To better load the high-temperature protective agent onto the porous material, the pore size of the selected porous material should be larger than the average particle size of the high-temperature protective agent, so that the high-temperature protective agent can enter the pores of the porous material as much as possible. Therefore, in this invention, the particle size of the porous material is 500-1000 mesh.

[0029] Furthermore, the introduction of activators can enhance the catalytic activity of biological enzymes, thereby exhibiting an activation effect, including but not limited to one or more of calcium hydroxide, barium oxide, and calcium oxide.

[0030] Furthermore, the introduction of surface modifiers can modify the surface of each powder, allowing the carrier material to be better added to the plastic matrix and improving the compatibility between the carrier material and the plastic matrix. The surface modifiers include, but are not limited to, one or more of γ-glycidyl etheroxypropyltrimethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, erucamide, stearamide, and N,N'-ethylene bis-stearamide.

[0031] Furthermore, the carrier material is prepared by the following method:

[0032] A high-temperature resistant protective agent and an activator containing biological enzymes are mixed evenly to obtain a premix. Then, porous materials and surface modifiers are added to the premix and mixed evenly to obtain a uniform carrier material.

[0033] To achieve the fourth objective mentioned above, the present invention adopts the following technical solution:

[0034] This invention discloses the application of the carrier material described above in the preparation of biodegradable polymer material products.

[0035] Furthermore, the specific steps for preparing biodegradable polymer material products are as follows:

[0036] The carrier material and the polymer material are thoroughly mixed and melt-processed at a temperature of 100-280℃ to obtain biodegradable polymer material products containing bioenzymes.

[0037] The beneficial effects of this invention are as follows:

[0038] (1) The carrier material of the present invention for improving the high temperature processing resistance of biological enzymes can fully protect biological enzymes during high temperature processing and improve the activity of biological enzymes after high temperature processing.

[0039] (2) The present invention innovatively introduces a high-temperature resistant protective agent with a core-shell structure into a carrier material for improving the high-temperature processing resistance of biological enzymes. Both the composition and the core-shell structure are beneficial to protecting biological enzymes from destruction at high temperatures, thus providing dual protection.

[0040] (3) The carrier material of the present invention for improving the high temperature processability of biological enzymes can be well dispersed in the polymer matrix and has good compatibility with the matrix.

[0041] (4) The carrier material of the present invention improves the high temperature resistance of bioenzymes. While protecting bioenzymes from high temperatures, it also takes into account the release and catalytic degradation of bioenzymes during the degradation process. Specifically, the encapsulated bioenzymes can be released after water molecules destroy the polyvinyl alcohol film, and have more efficient catalytic activity under the action of activator.

[0042] (5) The carrier material of the present invention for improving the high temperature processing resistance of bioenzymes can be applied to the high temperature processing process for preparing polymer materials containing bioenzymes. Detailed Implementation

[0043] To more clearly illustrate the present invention, the following description, in conjunction with preferred embodiments, further clarifies the invention. Those skilled in the art should understand that the specific descriptions below are illustrative rather than restrictive, and should not be construed as limiting the scope of protection of the present invention.

[0044] In this invention, the preparation methods are all conventional unless otherwise specified, and the raw materials used can be obtained from publicly available commercial sources or prepared according to existing technology unless otherwise specified.

[0045] Example 1

[0046] A carrier material for improving the high-temperature processing resistance of biological enzymes comprises the following raw materials, in parts by weight:

[0047]

[0048] The diatomaceous earth has a particle size of 3000 mesh, and the zeolite powder has a particle size of 800 mesh.

[0049] The preparation of the aforementioned carrier material for improving the high-temperature processing resistance of biological enzymes includes the following steps:

[0050] (1) Preparation of high-temperature resistant protective agent:

[0051] S1: Mix 1 part of proteinase K that needs to be protected and 1 part of polyacrylamide evenly, and mix at a low speed of 60 rpm for 30 min to obtain the core of the high temperature protective agent.

[0052] S2: Dissolve 5 parts of polyvinyl alcohol 0388 in deionized water at 90°C to obtain a polyvinyl alcohol 0388 aqueous solution, then cool it to 50°C, add the core of the high-temperature resistant protective agent prepared in S1, stir evenly, place it in a vacuum oven at 50°C for dehydration until it becomes viscous, then add 4 parts of diatomaceous earth evenly, stir for 30 minutes to obtain a high-temperature resistant protective agent with a core-shell structure.

[0053] (2) Preparation of carrier materials to improve the high-temperature processing resistance of bioenzymes:

[0054] S1: Mix the obtained high-temperature protective agent containing proteinase K with 1 part of calcium oxide evenly, and stir at 80 rpm for 15 min to obtain a premix;

[0055] S2: The premix prepared in S1 was added to 100 parts of zeolite powder and 1 part of γ-glycidyl etheroxypropyltrimethoxysilane and mixed evenly. The mixture was stirred at 80 rpm for 30 min to obtain a homogeneous carrier material.

[0056] (3) Preparation of polylactic acid containing biological enzymes, including the following steps:

[0057] The obtained carrier material was mixed with 10 parts of polylactic acid and stirred at 100 rpm for 10 minutes until the mixture was uniform. The mixture was then melt-extruded at a processing temperature of 200°C to obtain polylactic acid material containing bioenzymes.

[0058] Example 2

[0059] Compared with Example 1, the only difference is that the preparation of polylactic acid containing bio-enzymes in step 3 includes the following steps: the obtained carrier material is mixed with 5 parts of polylactic acid, stirred at 100 rpm for 10 min until the mixture is uniform, and melt extruded at a processing temperature of 200°C to obtain polylactic acid material containing bio-enzymes.

[0060] Example 3

[0061] A carrier material for improving the high-temperature processing resistance of biological enzymes comprises the following raw materials, in parts by weight:

[0062]

[0063] The diatomaceous earth has a particle size of 3000 mesh, and the zeolite powder has a particle size of 800 mesh.

[0064] The preparation of the aforementioned carrier material for improving the high-temperature processing resistance of biological enzymes includes the following steps:

[0065] (1) Preparation of high-temperature resistant protective agent:

[0066] S1: Mix 2 parts of proteinase K that needs to be protected and 2 parts of polyacrylamide evenly, and mix at a low speed of 60 rpm for 30 min to obtain the core of the high temperature protective agent.

[0067] S2: Dissolve 10 parts of polyvinyl alcohol 0388 in deionized water at 90°C to obtain a polyvinyl alcohol 0388 aqueous solution, then cool it to 50°C, add the core of the high-temperature resistant protective agent prepared in S1, stir evenly, place it in a vacuum oven at 50°C for dehydration until it becomes viscous, then add 8 parts of diatomaceous earth evenly, stir for 30 minutes to obtain a high-temperature resistant protective agent with a core-shell structure.

[0068] (2) Preparation of carrier materials to improve the high-temperature processing resistance of bioenzymes:

[0069] S1: Mix the obtained high-temperature protective agent containing proteinase K with 2 parts of calcium oxide evenly, and stir at 80 rpm for 15 min to obtain a premix;

[0070] S2: The premix prepared in S1 was added to 100 parts of zeolite powder and 2 parts of γ-glycidyl etheroxypropyltrimethoxysilane and mixed evenly. The mixture was stirred at 80 rpm for 30 min to obtain a homogeneous carrier material.

[0071] (3) Preparation of polylactic acid containing biological enzymes, including the following steps:

[0072] The obtained carrier material was mixed with 10 parts of polylactic acid and stirred at 100 rpm for 10 minutes until the mixture was uniform. The mixture was then melt-extruded at a processing temperature of 200°C to obtain polylactic acid material containing bioenzymes.

[0073] Example 4

[0074] A carrier material for improving the high-temperature processing resistance of biological enzymes comprises the following raw materials, in parts by weight:

[0075]

[0076] The diatomaceous earth has a particle size of 2500 mesh, and the vermiculite powder has a particle size of 500 mesh.

[0077] The preparation of the aforementioned carrier material for improving the high-temperature processing resistance of biological enzymes includes the following steps:

[0078] (1) Preparation of high-temperature resistant protective agent:

[0079] S1: Mix 1 part of the lipase to be protected and 3 parts of sodium polyacrylate evenly, and mix at a low speed of 60 rpm for 30 min to obtain the core of the high temperature resistant protective agent.

[0080] S2: Dissolve 15 parts of polyvinyl alcohol 0588 in deionized water at 90°C to obtain an aqueous solution of polyvinyl alcohol 0588. Then cool it to 50°C and add the core of the high-temperature resistant protective agent prepared in S1. Stir evenly and place it in a vacuum oven at 50°C for dehydration until it becomes viscous. Then add 12 parts of diatomaceous earth evenly and stir for 30 minutes to obtain a high-temperature resistant protective agent with a core-shell structure.

[0081] (2) Preparation of carrier materials to improve the high-temperature processing resistance of bioenzymes:

[0082] S1: Mix the obtained lipase-containing high-temperature protective agent with 2 parts of calcium hydroxide evenly, and stir at 80 rpm for 15 min to obtain a premix;

[0083] S2: The premix prepared in S1 was added to 100 parts vermiculite powder and 2 parts γ-methacryloyloxypropyltrimethoxysilane and mixed evenly. The mixture was stirred at 80 rpm for 30 min to obtain a homogeneous carrier material.

[0084] (3) Preparation of poly(butylene adipate) / terephthalate containing bioenzymes, comprising the following steps:

[0085] The obtained carrier material was mixed with 10 parts of poly(adipate adipate / butylene terephthalate) and stirred at 100 rpm for 10 min until the mixture was uniform. The mixture was then melt-extruded at a processing temperature of 170°C to obtain poly(adipate adipate / butylene terephthalate) material containing bio-enzymes.

[0086] Example 5

[0087] A carrier material for improving the high-temperature processing resistance of biological enzymes comprises the following raw materials, in parts by weight:

[0088]

[0089] The diatomite has a particle size of 2800 mesh, and the montmorillonite powder has a particle size of 800 mesh.

[0090] The preparation of the aforementioned carrier material for improving the high-temperature processing resistance of biological enzymes includes the following steps:

[0091] (1) Preparation of high-temperature resistant protective agent:

[0092] S1: Mix 1 part of the lipase to be protected and 1 part of ammonium polyacrylate evenly, and mix at a low speed of 60 rpm for 30 min to obtain the core of the high temperature resistant protective agent;

[0093] S2: Dissolve 5 parts of polyvinyl alcohol 1788 in deionized water at 90°C to obtain an aqueous solution of polyvinyl alcohol 1788. Then cool it to 50°C and add the core of the high-temperature resistant protective agent prepared in S1. Stir evenly and place it in a vacuum oven at 50°C for dehydration until it becomes viscous. Then add 4 parts of diatomaceous earth evenly and stir for 30 minutes to obtain a high-temperature resistant protective agent with a core-shell structure.

[0094] (2) Preparation of carrier materials to improve the high-temperature processing resistance of bioenzymes:

[0095] S1: Mix the obtained lipase-containing high-temperature protective agent with 1 part of barium oxide evenly, and stir at 80 rpm for 15 min to obtain a premix;

[0096] S2: The premix prepared in S1 was added to 100 parts of montmorillonite powder and 1 part of N,N'-ethylene bis-stearamide and mixed evenly. The mixture was stirred at 80 rpm for 30 min to obtain a homogeneous carrier material.

[0097] (3) Preparation of polybutylene succinate containing bioenzymes, comprising the following steps:

[0098] The obtained carrier material was mixed with 10 parts of polybutylene succinate and stirred at 100 rpm for 10 min until the mixture was uniform. The mixture was then melt-extruded at a processing temperature of 180°C to obtain polybutylene succinate material containing bio-enzymes.

[0099] Comparative Example 1

[0100] The preparation of polylactic acid containing bioenzymes includes the following steps:

[0101] One part of bio-enzyme was added to 10 parts of polylactic acid, and the mixture was stirred at 100 rpm for 10 minutes until it was uniformly mixed. The mixture was then melt-extruded at a processing temperature of 200°C to obtain polylactic acid material containing bio-enzyme.

[0102] Comparative Example 2

[0103] The only difference from Example 1 is that calcium oxide was not added; all other steps and experimental parameters are the same as in Example 1.

[0104] Comparative Example 3

[0105] A carrier material for improving the high-temperature processing resistance of biological enzymes comprises the following raw materials, in parts by weight:

[0106]

[0107] The diatomaceous earth has a particle size of 3000 mesh, and the zeolite powder has a particle size of 800 mesh.

[0108] The preparation of the aforementioned carrier material for improving the high-temperature processing resistance of biological enzymes includes the following steps:

[0109] (1) Preparation of carrier materials to improve the high-temperature processing resistance of bioenzymes:

[0110] S1: Mix 1 part proteinase K and 1 part calcium oxide evenly and stir at 80 rpm for 15 min to obtain the premix;

[0111] S2: The premix prepared in S1 was added to 100 parts of zeolite powder and 1 part of γ-glycidyl etheroxypropyltrimethoxysilane and mixed evenly. The mixture was stirred at 80 rpm for 30 min to obtain a homogeneous carrier material.

[0112] (2) Preparation of polylactic acid containing biological enzymes includes the following steps:

[0113] The obtained carrier material was mixed with 10 parts of polylactic acid and stirred at 100 rpm for 10 minutes until the mixture was uniform. The mixture was then melt-extruded at a processing temperature of 200°C to obtain polylactic acid material containing bioenzymes.

[0114] Comparative Example 4

[0115] A carrier material for improving the high-temperature processing resistance of biological enzymes comprises the following raw materials, in parts by weight:

[0116]

[0117] The diatomaceous earth has a particle size of 3000 mesh, and the zeolite powder has a particle size of 800 mesh.

[0118] The preparation of the aforementioned carrier material for improving the high-temperature processing resistance of biological enzymes includes the following steps:

[0119] (1) Preparation of high-temperature resistant protective agent:

[0120] S1: Mix 1 part of proteinase K that needs to be protected and 1 part of polyacrylamide evenly, and mix at a low speed of 60 rpm for 30 min to obtain a mixture;

[0121] S2: Mix 5 parts of polyvinyl alcohol 0388 and the mixture prepared by S1 evenly, then add 4 parts of diatomaceous earth evenly, and stir for 30 minutes to obtain a high-temperature resistant protective agent.

[0122] (2) Preparation of carrier materials:

[0123] S1: Mix the obtained high-temperature protective agent containing proteinase K with 1 part of calcium oxide evenly, and stir at 80 rpm for 15 min to obtain a premix;

[0124] S2: The premix prepared in S1 was added to 100 parts of zeolite powder and 1 part of γ-glycidyl etheroxypropyltrimethoxysilane and mixed evenly. The mixture was stirred at 80 rpm for 30 min to obtain a homogeneous carrier material.

[0125] (3) Preparation of polylactic acid containing biological enzymes, including the following steps:

[0126] The obtained carrier material was mixed with 10 parts of polylactic acid and stirred at 100 rpm for 10 minutes until the mixture was uniform. The mixture was then melt-extruded at a processing temperature of 200°C to obtain polylactic acid material containing bioenzymes.

[0127] Comparative Example 5

[0128] Compared with Example 1, the only difference is that the water-retaining agent polyacrylamide was not added; the other steps and experimental parameters are the same as in Example 1.

[0129] Test case

[0130] The materials prepared in Examples 1-5 and Comparative Examples 1-5 were injection molded into standard tensile specimens and placed in 0.01 mol / L phosphate buffer solution (PBS buffer, pH = 7.2-7.4) at 37°C. Mechanical properties and molecular weight were tested using a universal testing instrument and gel permeation chromatography, respectively. The initial molecular weight of polylactic acid was 6.6 × 10⁻⁶. 4 The initial molecular weight of poly(butylene adipate) / butylene terephthalate is 5.8 × 10 g / mol. 4 g / mol, the initial molecular weight of polybutylene succinate is 5.4 × 10⁻⁶ g / mol. 4 g / mol.

[0131] Table 1. Changes in mechanical properties of the embodiments and comparative examples.

[0132]

[0133] Table 2 shows the molecular weight variations of polymers in the examples and comparative examples.

[0134]

[0135] The test results in Table 1-2 show that:

[0136] (1) After 180 days in 0.01 mol / L PBS buffer at 37°C, the tensile strength and elongation at break of Example 1 decreased by 25% and 22%, respectively, and the molecular weight decreased by 38%, while the tensile strength and elongation at break of Comparative Example 1 decreased by 13% and 10%, respectively, and the molecular weight decreased by 18%. This shows that compared with adding biological enzymes directly to the polylactic acid matrix, the use of the carrier material provided by the present invention to improve the high-temperature processability of biological enzymes to protect and activate them significantly improves the catalytic activity of biological enzymes.

[0137] (2) After 180 days in 0.01 mol / L PBS buffer at 37°C, the tensile strength and elongation at break of Example 1 decreased by 25% and 22%, respectively, and the molecular weight decreased by 38%. In contrast, the tensile strength and elongation at break of Comparative Example 2 decreased by 20% and 11%, respectively, and the molecular weight decreased by 30%. This indicates that the activator plays a crucial role in the degradation process and is not a conventionally added component. Furthermore, considering the degradation levels of Comparative Example 1 and Comparative Example 2, it can be determined that the main reason for using the carrier material provided by this invention to promote polylactic acid degradation is the increased activity of the biological enzymes after high-temperature processing. The use of the activator is important, but relatively secondary.

[0138] (3) After 180 days in 0.01 mol / L PBS buffer at 37°C, the tensile strength and elongation at break of Example 1 decreased by 25% and 22%, respectively, and the molecular weight decreased by 38%, while the tensile strength and elongation at break of Comparative Example 3 decreased by 15% and 11%, respectively, and the molecular weight decreased by 26%. This shows that the role of the high-temperature resistant protective agent is very important in the degradation process and plays a leading role in promoting the degradation of polylactic acid in the carrier material provided by this invention.

[0139] (4) After 180 days in 0.01 mol / L PBS buffer at 37°C, the tensile strength and elongation at break of Example 1 decreased by 25% and 22%, respectively, and the molecular weight decreased by 38%. In contrast, the tensile strength and elongation at break of Comparative Example 4 decreased by 17% and 11%, respectively, and the molecular weight decreased by 29%. This demonstrates that the preparation process of the high-temperature resistant protective agent provided by this invention is related to its protective effect on biological enzymes. It is not a simple material mixing process, but rather a process that can prepare a high-temperature resistant protective agent with a core-shell structure. Therefore, during the degradation process, the core-shell structure of the high-temperature resistant protective agent plays a significant role in protecting the high-temperature processability of biological enzymes.

[0140] (5) After 180 days in 0.01 mol / L PBS buffer at 37°C, the tensile strength and elongation at break of Example 1 decreased by 25% and 22%, respectively, and the molecular weight decreased by 38%, while the tensile strength and elongation at break of Comparative Example 5 decreased by 21% and 22%, respectively, and the molecular weight decreased by 32%. This shows that the water-retaining agent plays a certain important role in the degradation process and is not a conventionally added component.

[0141] (6) After 180 days in 0.01 mol / L PBS buffer at 37°C, the tensile strength and elongation at break of Example 1 decreased by 25% and 22%, respectively, and the molecular weight decreased by 38%. The tensile strength and elongation at break of Example 2 decreased by 47% and 38%, respectively, and the molecular weight decreased by 68%. This shows that when the same carrier material that improves the high-temperature processing resistance of the bioenzyme is used, and the mass ratio of the bioenzyme to polylactic acid is increased to 2 times, the degree of degradation of the polylactic acid matrix will also be nearly 2 times, which indicates a significant improvement in the catalytic activity of the bioenzyme.

[0142] (7) After 180 days at 37°C with 0.01 mol / L PBS buffer, the tensile strength and elongation at break of Example 2 decreased by 47% and 38%, respectively, and the molecular weight decreased by 68%. The tensile strength and elongation at break of Example 3 decreased by 36% and 38%, respectively, and the molecular weight decreased by 48%. This indicates that although the mass ratio of bio-enzyme to polylactic acid is the same, when 100 parts of porous material are loaded with 11 parts of heat-resistant protective agent, compared with 22 parts of heat-resistant protective agent, the degradation effect on polylactic acid matrix is ​​more obvious. This may be because the relative content of heat-resistant protective agent is too high, exceeding the limit that the porous material can load, thereby reducing the protection efficiency of bio-enzyme.

[0143] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. For those skilled in the art, other variations or modifications can be made based on the above description. It is impossible to exhaustively list all the implementation methods here. All obvious variations or modifications derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. A carrier material that can improve the high-temperature processing resistance of biological enzymes, characterized in that, By weight, it includes 11-31 parts of high-temperature protective agent, 100 parts of porous material, 1-3 parts of activator and 1-5 parts of surface modifier; The high-temperature resistant protective agent includes a core material and a shell material. The core material is a biological enzyme and a water-retaining agent, and the shell material is a composite layer of polyvinyl alcohol and an adsorbent and dispersant covering the core material. The mass ratio of the bio-enzyme, polyvinyl alcohol, water-retaining agent, and adsorption dispersant is 1:5-15:1-3:4-12; The water-retaining agent includes one or more of polyacrylamide, sodium polyacrylate, potassium polyacrylate, and ammonium polyacrylate; The adsorbent and dispersant is diatomaceous earth; The porous material is selected from one or more of the following: zeolite powder, sepiolite powder, vermiculite powder, perlite powder, gypsum powder, and montmorillonite powder. The activator is selected from one or more of calcium hydroxide, barium oxide, and calcium oxide; The surface modifier is selected from one or more of γ-glycidyl etheroxypropyltrimethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, and N,N'-ethylenebisstearamide; The preparation of the high-temperature resistant protective agent includes the following steps: S1. Mix the biological enzyme and water-retaining agent evenly to obtain the core of the high-temperature resistant protective agent; S2. Dissolve polyvinyl alcohol in deionized water, then add the core prepared in step 1 at 45-55℃, stir evenly, place in a vacuum oven for dehydration until viscous, and then add the adsorption dispersant evenly to obtain a high-temperature resistant protective agent with a core-shell structure.

2. The carrier material according to claim 1, characterized in that, The polyvinyl alcohol includes one or more of polyvinyl alcohol 0388, polyvinyl alcohol 0588, and polyvinyl alcohol 1788.

3. The carrier material according to claim 2, characterized in that, The mass ratio of the bio-enzyme, polyvinyl alcohol 0388, polyacrylamide, and diatomaceous earth is 1:5-15:1-3:4-12.

4. The carrier material according to claim 2, characterized in that, The mass ratio of the bio-enzyme, polyvinyl alcohol 0588, sodium polyacrylate and diatomaceous earth is 1:5-15:1-3:4-12.

5. The carrier material according to claim 2, characterized in that, The mass ratio of the bio-enzyme, polyvinyl alcohol 1788, ammonium polyacrylate and diatomaceous earth is 1:5-15:1-3:4-12.

6. The carrier material according to claim 1, characterized in that, The particle size of the adsorbent dispersant is 2500-3000 mesh.

7. The carrier material according to claim 1, characterized in that, The carrier material is prepared by the following method: A high-temperature resistant protective agent and an activator containing biological enzymes are mixed evenly to obtain a premix. Then, porous materials and surface modifiers are added to the premix and mixed evenly to obtain a uniform carrier material.

8. The application of the carrier material according to any one of claims 1-7 in the preparation of biodegradable polymer material products, characterized in that, The specific steps for preparing biodegradable polymer material products are as follows: The carrier material and the polymer material are thoroughly mixed and processed at a temperature of 100-280℃ to obtain biodegradable polymer material products containing bioenzymes.

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