A process for preparing a compatibilizer, articles and applications

Abstract

The present application relates to the technical field of high polymer materials, and more particularly to a preparation process of a compatibilizer, an article and application thereof, and provides a preparation process of a compatibilizer, which comprises the following steps: 1) adding polyester material and solvent into a three-necked flask, heating, stirring, introducing nitrogen, adding a reaction monomer, adding an initiator after stirring, and obtaining a product after reaction; 2) after cooling the product, adding an extraction liquid while stirring, vacuum filtering, and obtaining the product after purification. The compatibilizer prepared by the process has high grafting rate, which is beneficial to improving the total grafting rate, and when applied to silk sericin composite material, the mechanical properties and thermal properties of the composite material are improved, the maximum degradation temperature can reach 402 DEG C, and the application prospect is wide.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, and more specifically, to a compatibilizer preparation process, product, and application. Background Technology

[0002] In recent years, traditional petrochemical-based plastics are gradually being replaced by biodegradable and reusable bio-based materials, often referred to as "green materials." Currently, the most important and widely used biodegradable polymers are aliphatic polyesters and proteins, such as polylactic acid (PLA) and polybutylene adipate terephthalate (PBAT). Sericin, as a natural protein, has good water solubility, and its functional groups can undergo cross-linking and copolymerization with other compounds, giving it broader application prospects. However, because PBAT and sericin form an incompatible two-phase system, the compatibility between the multiple phases in the blend is poor, resulting in minimal improvement in the mechanical and thermal properties of the composite material, and even a decrease in some properties. Therefore, compatibilizers are needed to improve their compatibility. By modifying PBAT and sericin, the interfacial compatibility can be improved, leading to better and more stable composite materials. However, existing compatibilizers generally suffer from low grafting rates during preparation and offer only minor improvements in mechanical properties when applied to sericin composites. Summary of the Invention

[0003] To address the aforementioned technical problems, a first aspect of the present invention provides a process for preparing a compatibilizer, comprising at least the following steps:

[0004] (1) Add polyester material and solvent to a three-necked flask, heat and stir, introduce nitrogen gas, add reaction monomer, stir and then add initiator. After the reaction is complete, the product is obtained.

[0005] (2) After the product is cooled, the extract is added while stirring, and the product is vacuum filtered and purified to obtain the final product.

[0006] As a preferred embodiment of the present invention, the polyester material is selected from one or more of polybutylene adipate terephthalate, polyhydroxyalkanoate, polybutylene succinate, and polybutylene adipate succinate.

[0007] As a preferred embodiment of the present invention, the solvent is selected from one or more of xylene, toluene, and decahydronaphthalene.

[0008] In a preferred embodiment of the present invention, the amount of polyester material added is 15-25g, and the amount of solvent added is 180-220mL.

[0009] As a preferred embodiment of the present invention, the heating temperature is raised to 75-105°C and the reaction time is 2-6 hours.

[0010] As a preferred embodiment of the present invention, the reaction monomer is selected from one or more of maleic anhydride, acrylic acid, methyl methacrylate, glycidyl methacrylate, styrene, N-vinylpyrrolidone, 2-vinylpyridine, acrylonitrile, and dibutyl maleate.

[0011] As a preferred embodiment of the present invention, the amount of the reactive monomer added accounts for 10-50% of the mass percentage of the polyester material.

[0012] As a preferred embodiment of the present invention, the amount of initiator added accounts for 0.5% to 3% of the mass percentage of the polyester material.

[0013] A second aspect of the present invention provides a compatibilizer prepared using the above-described preparation process.

[0014] A third aspect of the invention provides the use of the compatibilizer in the preparation of sericin composite materials.

[0015] Beneficial effects: This invention provides a compatibilizer preparation process, product and application. The compatibilizer prepared by the process of this invention not only helps to improve the total grafting rate, but also improves the mechanical and thermal properties of the composite material when applied to sericin composite materials. The maximum degradation temperature can reach 402℃, and the application prospects are broad. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 (a) Infrared spectrum and (b) Differential spectrum of the compatibilizer and PBAT in Examples 3-4 of this invention;

[0018] Figure 2 The images show SEM images of the fracture surfaces of the sericin composite materials prepared in Examples 7, 10-11 and the control examples of the present invention. Detailed Implementation

[0019] The invention will be more readily understood by referring to the following detailed description of preferred embodiments and included examples. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. In case of conflict, the definitions in this specification shall prevail.

[0020] The terms “comprising,” “including,” “having,” “containing,” or any other variations thereof, as used herein, are intended to cover a non-exclusive inclusion. For example, a composition, step, method, article, or apparatus that includes the listed elements is not necessarily limited to those elements, but may include other elements not expressly listed or elements inherent to such composition, step, method, article, or apparatus.

[0021] When a quantity, concentration, or other value or parameter is expressed as a range, a preferred range, or a range defined by a series of upper and lower preferred values, this should be understood as specifically disclosing all ranges formed by any pair of any upper or preferred value with any lower or preferred value, regardless of whether the range is disclosed individually. For example, when the range “1 to 5” is disclosed, the described range should be interpreted as including the ranges “1 to 4”, “1 to 3”, “1 to 2”, “1 to 2 and 4 to 5”, “1 to 3 and 5”, etc. When numerical ranges are described herein, unless otherwise stated, the range is intended to include its endpoints and all integers and fractions within that range.

[0022] Furthermore, the indefinite articles “a” and “an” preceding the elements or components of this invention do not impose any limitation on the quantity (i.e., number of occurrences) of the elements or components. Therefore, “an” or “a” should be interpreted as including one or at least one, and the singular form of an element or component also includes the plural form, unless the quantity clearly refers only to the singular form.

[0023] To address the aforementioned technical problems, the first aspect of this invention provides a process for preparing a compatibilizer, comprising the following steps:

[0024] (1) Add polyester material and solvent to a three-necked flask, heat and stir, introduce nitrogen gas, add reaction monomer, stir and then add initiator. After the reaction is complete, the product is obtained.

[0025] (2) After the product is cooled, the extract is added while stirring, and the product is vacuum filtered and purified to obtain the final product.

[0026] In one embodiment, the polyester material is selected from one or more of polybutylene adipate terephthalate, polyhydroxyalkanoate, polybutylene succinate, and polybutylene adipate succinate. Preferably, the polyester material is polybutylene adipate terephthalate, abbreviated as PBAT, which is a copolymer of butylene adipate and butylene terephthalate, possessing the characteristics of both PBA and PBT. Its structure contains long-chain aliphatic segments, facilitating intermolecular rotation and slip, giving it good flexibility. Simultaneously, it contains a rigid large benzene ring structure, making it a novel "rigid-flexible" material that can meet the performance requirements of various functional materials. This material was purchased from Xinjiang Lanshan Tunhe Polyester Co., Ltd.

[0027] In one embodiment, the solvent is selected from one or more of xylene, toluene, and decahydronaphthalene. Preferably, the solvent is xylene.

[0028] In one embodiment, the amount of polyester material added is 15-25g, and the amount of solvent added is 180-220mL. Preferably, the amount of polyester material added is 20g, and the amount of solvent added is 200mL.

[0029] In one embodiment, the heating is raised to 75–105°C, and the reaction time is 2–6 hours. Preferably, the heating is raised to 90–100°C, and the reaction time is 3–5 hours. More preferably, the heating is raised to 95°C, and the reaction time is 4 hours. The applicant has found that reaction temperature and time have a significant impact on the grafting rate of the product. When the reaction temperature is too high, the rate of primary free radical generation from the thermal decomposition of the initiator may be accelerated, resulting in a high concentration of free radicals in the PBAT macromolecule. These free radicals may also self-polymerize while reacting with the reactant monomers, reducing the utilization efficiency of the initiator. When the temperature is too low, the rate of thermal decomposition of the initiator is slow, resulting in fewer free radicals and fewer active sites for the PBTA macromolecules to undergo the grafting reaction, thus degrading the grafting rate. At the same time, the activation energy of the reaction system is low, the diffusion rate of each substance is low, and the probability of mutual collision is reduced, limiting the occurrence of free radical grafting reactions. If the grafting reaction time is too short, only some compounds undergo the grafting reaction; if it is too long, it will affect the reaction efficiency. Only when the reaction temperature is controlled at 75–105℃ and the reaction time at 2–6h, especially at 90–100℃ and at 3–5h, can the above-mentioned problems be avoided and the grafting rate be the highest. The applicant found that the higher the grafting rate, the better the compatibilization effect. When applied to the preparation of sericin composite materials, the maximum degradation temperature can reach 402℃, while also having good mechanical properties.

[0030] In one embodiment, the reactive monomer is selected from one or more of maleic anhydride, acrylic acid, methyl methacrylate, glycidyl methacrylate, styrene, N-vinylpyrrolidone, 2-vinylpyridine, acrylonitrile, and dibutyl maleate.

[0031] In a preferred embodiment, the reactive monomers include maleic anhydride and / or glycidyl methacrylate. Maleic anhydride (MAH) is a white crystalline solid with a strong, pungent odor at room temperature. Its molecular structure features 1,2-disubstituted components and exhibits strong electron-withdrawing effects and steric hindrance, making homopolymerization difficult. This increases the conversion rate of the initiator and monomer, providing favorable conditions for the grafting reaction. Simultaneously, this reactive monomer is primarily linked to the polymer chain via a single ring, forming a polar side chain. Its polarity is not excessively strong, ensuring that the grafted product's binding performance to non-polar phases is not reduced, and also enhancing its binding ability to polar substances. Glycidyl methacrylate (GMA) contains carbon-carbon double bonds and epoxy groups, readily undergoing ring-opening reactions with functional groups such as hydroxyl, carboxyl, and amino groups. It also exhibits low toxicity and is easily polymerized.

[0032] In a more preferred embodiment, the weight ratio of maleic anhydride to glycidyl methacrylate is (25-100):(0-75). In a more preferred embodiment, the reactant monomer includes maleic anhydride. In another more preferred embodiment, the weight ratio of maleic anhydride to glycidyl methacrylate is (50-75):(25-75). The weight ratio of maleic anhydride to glycidyl methacrylate is 75:25. Both maleic anhydride and glycidyl methacrylate contain double bonds and can undergo a free radical grafting reaction with PBAT. Under high temperature conditions, the initiator cleaves into two primary free radicals, which are highly reactive and can steal H atoms from the PBAT backbone to generate PBAT free radicals. The double bonds of the monomers MAH or GMA combine with PBAT radicals, undergoing chain growth, chain transfer, and chain termination reactions to yield the monofunctional compatibilizer MAH-g-PBAT (MPB) or the bifunctional compatibilizer MAH / GMA-PBAT (GMPB). In the dual-monomer system, the monomer properties differ, and the monomer ratio also affects the grafting rate. MAH has high activity and is not prone to homopolymerization. GMA, on the other hand, is larger in volume than MAH and has low reactivity to macromolecular free radicals. When GMA is grafted alone, it is prone to self-polymerization, resulting in a low grafting rate. The applicant unexpectedly discovered that when the weight ratio of maleic anhydride to glycidyl methacrylate is selected as (25-100):(0-75), especially when the weight ratio of maleic anhydride to glycidyl methacrylate is (50-75):(25-75), it is not only beneficial to improve the total grafting rate, but also improves the mechanical and thermal properties of the composite material when applied to sericin composites. The maximum degradation temperature can reach 402℃, and the overall performance is excellent.

[0033] In one embodiment, the amount of reactive monomer added is 10-50% of the mass percentage of the polyester material. Preferably, the amount of reactive monomer added is 20-40% of the mass percentage of the polyester material. More preferably, the amount of reactive monomer added is 30% of the mass percentage of the polyester material. The applicant has found that when the amount of reactive monomer added is 10-50% of the mass percentage of the polyester material, especially when the amount of reactive monomer added is 20-40% of the mass percentage of the polyester material, the overall grafting rate is maximized and the utilization efficiency of the reactive monomer is highest.

[0034] In one embodiment, the initiator is added at a mass percentage of 0.5% to 5% of the polyester material. Preferably, the initiator is added at a mass percentage of 2% to 4% of the polyester material. More preferably, the initiator is added at a mass percentage of 3% of the polyester material.

[0035] In one embodiment, the initiator is selected from one or more of benzoyl peroxide, cumene peroxide, and tert-butyl peroxide. Preferably, the initiator is benzoyl peroxide.

[0036] In one embodiment, the extractant is acetone. The extractant is primarily used to extract the maleic anhydride and its homopolymer remaining after the reaction, and there is no specific limitation on the amount added.

[0037] A second aspect of the present invention provides a compatibilizer prepared using the above-described preparation process.

[0038] A third aspect of the present invention provides the use of the compatibilizer in the preparation of sericin composite materials.

[0039] In one embodiment, the raw materials for preparing the sericin composite material include sericin and PBAT. Sericin is a globular protein containing 16 amino acids, with polar amino acid side chains containing functional groups such as -OH, -COOH, and -NH2. Therefore, sericin has good water solubility and was purchased from Dali Silk (Zhejiang) Co., Ltd. Due to the significant difference in polarity between sericin and PBAT, the bonding strength between the two components is low, resulting in poor mechanical properties of the Sericin / PBAT composite material.

[0040] In a more preferred embodiment, the weight ratio of the sericin to PBAT is 90:10.

[0041] In one embodiment, the compatibilizer is added at a rate of 2-9% of the sericin composite material. Specifically, the mass of the compatibilizer is 2-9% of the total mass of the sericin composite material (excluding the mass of the compatibilizer). Preferably, the compatibilizer is added at a rate of 3-7% of the sericin composite material. More preferably, the compatibilizer is added at a rate of 3% of the sericin composite material. The applicant has found that adding the compatibilizer prepared by the process described in this invention and limiting the amount of the compatibilizer to 3% of the sericin composite material improves the mechanical and thermal properties of the composite material. This may be because the MAH branched on the compatibilizer backbone contains anhydride groups, which can form two carboxyl groups after ring opening. The epoxy group in the GMA segment has a three-membered ring structure with high stress, and it easily undergoes ring-opening reactions with hydroxyl, mercapto, and primary amino groups. The two phases can enhance the interfacial forces through chemical bonding, which is beneficial to improving the overall performance of the composite material.

[0042] In a preferred embodiment, the method for preparing the sericin composite material includes the following steps:

[0043] Compatibilizer was added to sericin and PBAT at a weight ratio of 90:10, stirred evenly, and poured into a twin-screw extruder for granulation and injection molding. The extrusion temperatures were 140℃ in zone I, 145℃ in zone II, and 145℃ in zone III, respectively. The injection temperature was 150℃, the injection pressure was 45 MPa, and the cooling temperature was 35℃ to obtain the sericin composite material.

[0044] Example

[0045] To better understand the above technical solutions, a detailed description of the specific implementation methods will be provided below. It is important to note that the following embodiments are only for further illustration of the present invention and should not be construed as limiting the scope of protection of the present invention. Non-essential improvements and adjustments made by those skilled in the art based on the above description of the present invention still fall within the scope of protection of the present invention. Furthermore, unless otherwise stated, all raw materials used are commercially available.

[0046] Example 1

[0047] Example 1 of the present invention provides a compatibilizer, the preparation process of which includes the following steps:

[0048] (1) Polyester material and solvent were added to a three-necked flask, heated, stirred, and nitrogen gas was introduced. The reactant monomer was added, and after stirring, the initiator was added. After the reaction was completed, the product was obtained. The polyester material was PBAT, purchased from Xinjiang Lanshan Tunhe Polyester Co., Ltd., and the amount added was 20g. The solvent was xylene, and the amount added was 200mL. The temperature was raised to 90℃ and the reaction time was 3h. The reactant monomer was maleic anhydride and glycidyl methacrylate in a weight ratio of 50:75, and the amount added accounted for 20% of the mass percentage of the polyester material. The initiator was benzoyl peroxide, and the amount added accounted for 2% of the mass percentage of the polyester material.

[0049] (2) After the product is cooled, the extract is added while stirring, and the product is vacuum filtered and purified to obtain the final product; the extract is acetone.

[0050] Example 2

[0051] Example 2 of the present invention provides a compatibilizer, the preparation process of which includes the following steps:

[0052] (1) Polyester material and solvent were added to a three-necked flask, heated, stirred, and nitrogen gas was introduced. The reactant monomer was added, and after stirring, the initiator was added. After the reaction was completed, the product was obtained. The polyester material was PBAT, purchased from Xinjiang Lanshan Tunhe Polyester Co., Ltd., and the amount added was 20g. The solvent was xylene, and the amount added was 200mL. The temperature was raised to 100℃ and the reaction time was 5h. The reactant monomer was maleic anhydride and glycidyl methacrylate in a weight ratio of 50:25, and the amount added accounted for 40% of the mass percentage of the polyester material. The initiator was benzoyl peroxide, and the amount added accounted for 4% of the mass percentage of the polyester material.

[0053] (2) After the product is cooled, the extract is added while stirring, and the product is vacuum filtered and purified to obtain the final product; the extract is acetone.

[0054] Example 3

[0055] Example 3 of the present invention provides a compatibilizer, the preparation process of which includes the following steps:

[0056] (1) Polyester material and solvent were added to a three-necked flask, heated, stirred, and nitrogen gas was introduced. The reactant monomer was added, and after stirring, the initiator was added. After the reaction was completed, the product was obtained. The polyester material was PBAT, purchased from Xinjiang Lanshan Tunhe Polyester Co., Ltd., and the amount added was 20g. The solvent was xylene, and the amount added was 200mL. The temperature was raised to 95℃ and the reaction time was 4h. The reactant monomer was maleic anhydride and glycidyl methacrylate in a weight ratio of 75:25, and the amount added accounted for 30% of the mass percentage of the polyester material. The initiator was benzoyl peroxide, and the amount added accounted for 3% of the mass percentage of the polyester material.

[0057] (2) After the product is cooled, the extract is added while stirring, and the product is vacuum filtered and purified to obtain the final product; the extract is acetone.

[0058] Example 4

[0059] Example 4 of the present invention provides a compatibilizer, the preparation process of which includes the following steps:

[0060] (1) The polyester material and solvent were added to a three-necked flask, heated, stirred, and nitrogen gas was introduced. The reactant monomer was added, and after stirring, the initiator was added. After the reaction was completed, the product was obtained. The polyester material was PBAT, purchased from Xinjiang Lanshan Tunhe Polyester Co., Ltd., and the amount added was 20g. The solvent was xylene, and the amount added was 200mL. The temperature was raised to 95℃ and the reaction time was 4h. The reactant monomer was maleic anhydride, and the amount added accounted for 30% of the mass percentage of the polyester material. The initiator was benzoyl peroxide, and the amount added accounted for 3% of the mass percentage of the polyester material.

[0061] (2) After the product is cooled, the extract is added while stirring, and the product is vacuum filtered and purified to obtain the final product; the extract is acetone.

[0062] Example 5

[0063] Example 5 of the present invention provides a compatibilizer, the preparation process of which includes the following steps:

[0064] (1) Polyester material and solvent were added to a three-necked flask, heated, stirred, and nitrogen gas was introduced. The reactant monomer was added, and after stirring, the initiator was added. After the reaction was completed, the product was obtained. The polyester material was PBAT, purchased from Xinjiang Lanshan Tunhe Polyester Co., Ltd., and the amount added was 20g. The solvent was xylene, and the amount added was 200mL. The temperature was raised to 105℃ and the reaction time was 5h. The reactant monomer was maleic anhydride, and the amount added accounted for 30% of the mass percentage of the polyester material. The initiator was benzoyl peroxide, and the amount added accounted for 3% of the mass percentage of the polyester material.

[0065] (2) After the product is cooled, the extract is added while stirring, and the product is vacuum filtered and purified to obtain the final product; the extract is acetone.

[0066] Example 6

[0067] Example 6 of the present invention provides a compatibilizer, the preparation process of which includes the following steps:

[0068] (1) Polyester material and solvent were added to a three-necked flask, heated, stirred, and nitrogen gas was introduced. The reactant monomer was added, and after stirring, the initiator was added. After the reaction was completed, the product was obtained. The polyester material was PBAT, purchased from Xinjiang Lanshan Tunhe Polyester Co., Ltd., and the amount added was 20g. The solvent was xylene, and the amount added was 200mL. The temperature was raised to 105℃ and the reaction time was 5h. The reactant monomer was maleic anhydride and glycidyl methacrylate in a weight ratio of 75:25, and the amount added accounted for 30% of the mass percentage of the polyester material. The initiator was benzoyl peroxide, and the amount added accounted for 3% of the mass percentage of the polyester material.

[0069] (2) After the product is cooled, the extract is added while stirring, and the product is vacuum filtered and purified to obtain the final product; the extract is acetone.

[0070] Example 7

[0071] Example 7 of the present invention provides a sericin composite material, the raw materials of which include the compatibilizer prepared in Example 3, and the preparation method includes the following steps:

[0072] A compatibilizer was added to sericin and PBAT at a weight ratio of 90:10, stirred evenly, and then poured into a twin-screw extruder for granulation and injection molding. The extrusion temperatures were 140°C in zone I, 145°C in zone II, and 145°C in zone III, respectively. The injection temperature was 150°C, the injection pressure was 45 MPa, and the cooling temperature was 35°C to obtain a sericin composite material. The amount of compatibilizer added accounted for 3% of the sericin composite material.

[0073] Example 8

[0074] Example 8 of the present invention provides a sericin composite material, the raw materials of which include the compatibilizer prepared in Example 3, and the preparation method includes the following steps:

[0075] A compatibilizer was added to sericin and PBAT at a weight ratio of 90:10, stirred evenly, and then poured into a twin-screw extruder for granulation and an injection molding machine for injection molding. The extrusion temperatures were 140°C in zone I, 145°C in zone II, and 145°C in zone III, respectively. The injection temperature was 150°C, the injection pressure was 45 MPa, and the cooling temperature was 35°C to obtain a sericin composite material. The amount of compatibilizer added accounted for 5% of the sericin composite material.

[0076] Example 9

[0077] Example 9 of the present invention provides a sericin composite material, the raw materials of which include the compatibilizer prepared in Example 3, and the preparation method includes the following steps:

[0078] A compatibilizer was added to sericin and PBAT at a weight ratio of 90:10, stirred evenly, and then poured into a twin-screw extruder for granulation and an injection molding machine for injection molding. The extrusion temperatures were 140℃ in zone I, 145℃ in zone II, and 145℃ in zone III, respectively. The injection temperature was 150℃, the injection pressure was 45 MPa, and the cooling temperature was 35℃ to obtain a sericin composite material. The amount of compatibilizer added accounted for 7% of the sericin composite material.

[0079] Example 10

[0080] Example 10 of the present invention provides a sericin composite material, the raw materials of which include the compatibilizer prepared in Example 4, and the preparation method includes the following steps:

[0081] A compatibilizer was added to sericin and PBAT at a weight ratio of 90:10, stirred evenly, and then poured into a twin-screw extruder for granulation and injection molding. The extrusion temperatures were 140°C in zone I, 145°C in zone II, and 145°C in zone III, respectively. The injection temperature was 150°C, the injection pressure was 45 MPa, and the cooling temperature was 35°C to obtain a sericin composite material. The amount of compatibilizer added accounted for 3% of the sericin composite material.

[0082] Example 11

[0083] Example 11 of the present invention provides a sericin composite material, the raw material of which includes commercially available ADR-4370S (BASF), and the preparation method includes the following steps:

[0084] A compatibilizer was added to sericin and PBAT at a weight ratio of 90:10, stirred evenly, and then poured into a twin-screw extruder for granulation and injection molding. The extrusion temperatures were 140℃ in zone I, 145℃ in zone II, and 145℃ in zone III, respectively. The injection temperature was 150℃, the injection pressure was 45 MPa, and the cooling temperature was 35℃ to obtain a sericin composite material. The amount of compatibilizer added accounted for 0.2% of the sericin composite material (this amount yielded the best performance).

[0085] Performance testing

[0086] 1. Grafting rate test: Weigh 0.2g of the compatibilizer prepared in Examples 1-6 above into 20ml of dichloromethane, stir to dissolve, add two drops of bromothymol blue indicator, and titrate directly with 0.05mol / L NaOH-ethanol solution until blue-green. The MAH grafting rate is calculated as follows: G (MAH) =98.06×C NaOH-乙醇 (V5-V0) / (2×1000×W), where: C NaOH-乙醇 — Molar concentration of NaOH-ethanol solution, mol / L; V0— Volume of NaOH-ethanol solution consumed in titration of blank PBAT, mL; V5— Volume of NaOH-ethanol solution consumed during titration, mL; 98.06— Relative molecular mass of MAH; W— Mass of purified graft sample, g.

[0087] Weigh 0.2g of the compatibilizers prepared in Examples 1-6 above into dichloromethane, stir to dissolve, add 4mL of excess HCl-isopropanol solution, heat under reflux for 90min, and then titrate with NaOH-ethanol solution in reverse to the endpoint. The grafting rate of GMA is calculated using the following formula: G (GAM) =142.15×[C HCl-异丙醇 V7-C NaOH -ethanol(V6-V5) / (1000×W), where: C HCl-异丙醇 —Concentration of HCl-isopropanol solution, mol / L; V5—Calculation of G (GAM) V6—Volume of NaOH-ethanol solution consumed during titration, mL; V7—Volume of excess HCl-isopropanol solution added, mL; 142.15—Relative molecular mass of GMA.

[0088] The total grafting rate is the sum of the grafting rates of GMA and MAH. The test results are shown in Table 1 below.

[0089] Table 1 Grafting Rate

[0090]

[0091]

[0092] 2. Infrared Spectroscopy Test: Weigh 5g of the GMPB, MPB, and blank sample PBAT prepared in Examples 3-4 above, and place them separately on two polytetrafluoroethylene films. Press them together on a hot press at 145℃. Spectroscopy is performed using a Fourier transform infrared spectrometer at 400–4000 cm⁻¹. -1 The sample was subjected to 16 consecutive scans using the ATR method within the spectral range for infrared spectral analysis (FTIR). Figure 1 The compatibilizers and PBAT described in Examples 3-4 of this invention are shown in (a) infrared spectra and (b) difference spectra, respectively. Figure 1 (a) A signal peak (1630 cm⁻¹) without C=C can be observed. -1 This indicates that the MAH and GMA monomers were completely removed during the purification process. Comparing MPB, GMPB, and PBAT, it can be seen that the grafted product reaches 1781 cm⁻¹. -1 A new peak appears, which is a characteristic absorption peak of cyclic anhydrides, and the more MAH grafts there are, the more obvious this peak becomes. Figure 1 (b) shows the infrared difference spectrum of GMPB and PBAT. The GMA molecular chain on the side chain of GMPB, like that of PBAT, belongs to the ester family, and their functional group structures are extremely similar, making them difficult to distinguish directly from the spectrum. The difference spectrum reveals a difference at 1781 cm⁻¹. -1 1709cm -1 1250cm-1 1100cm -1 1016cm -1 916cm -1 There are obvious peaks everywhere, and the side chain GMA enhances the intensity of these characteristic peaks, which indirectly indicates that GMA has been successfully grafted onto PBAT.

[0093] 3. Mechanical property testing: The sericin composite materials prepared in Examples 7-10 above were subjected to mechanical property testing in a universal testing machine, with a control example without compatibilizer. Referring to standard GB / T 1040.1-2018, the dumbbell sample size was 75mm × 4mm × 2mm, and the tensile rate was 200mm / min. The test results are shown in Table 2 below.

[0094] Table 2 Mechanical Properties

[0095] Tensile strength (MPa) Elongation at break (%) Example 7 19 380 Example 8 12.5 315 Example 9 13.5 280 Example 10 22 380 Example 11 18 379 Comparison Example 14.8 331

[0096] Comparative analysis showed that the mechanical properties of the composite material gradually increased with increasing GMPB content, reaching a peak at 3% GMPB content, with a tensile strength of 19 MPa and an elongation at break of 380%. Further increasing the GMPB content led to increased copolymer formation and significant phase separation, weakening the mechanical properties of the composite material. Therefore, the optimal GMPB content was 3%. Comparative studies of Examples 7, 10, and 11 showed little difference in elongation at break, while Example 10 exhibited a significant improvement in tensile strength. In summary, adding 3% GMPB or MPB effectively improved the mechanical properties of the composite material, outperforming the addition of ADR.

[0097] 4. Thermal performance test: 5-8 mg of the sericin composite materials prepared in Examples 7 and 10-11 were placed in a thermogravimetric analyzer and heated from room temperature to 800°C at a rate of 10°C / min under a nitrogen atmosphere. A control example without compatibilizer was also included. The thermal weight loss was observed. The test results are shown in Table 3 below.

[0098] Table 3 Maximum Degradation Temperature

[0099] Maximum degradation temperature (°C) Example 7 402 Example 10 397.8 Example 11 399.3 Comparison Example 397.6

[0100] Comparative analysis showed that the thermal stability of the composite materials with MPB added in Example 10 and ADR added in Example 11 was not significantly improved, while the maximum degradation temperature of the composite material with GMPB added in Example 7 reached 402℃, exhibiting good thermal stability and being less prone to aging, deterioration, and failure. This improved its performance and safety, reduced costs and maintenance costs, and made it widely applicable.

[0101] 5. SEM testing: The sericin composite materials prepared in Examples 7 and 10-11 were placed in liquid nitrogen to cool and fracture, and the fractured sections were sputter-coated with gold. Then, the microstructure of the composite material fracture surface was observed under a scanning electron microscope with an accelerating voltage of 12.5-15.0 kV and a control example without compatibilizer (PBAT90-Ser10) was included. Figure 2 The images show SEM images of the fracture surfaces of the sericin composite materials prepared in Examples 7, 10-11, and the control example of the present invention. Figure 2 (a) is a SEM image of the fracture surface of the control example. The fracture surface is very rough, with many particles and very large pores, which indicates that the adhesion between sericin and PBAT is poor and obvious separation occurs. Figure 2 (b) SEM image of the fracture surface of PBAT90-Ser10-0.2% ADR prepared in Example 11. Figure 2 (c) SEM of the fracture surface of PBAT90-Ser10-3%GMPB prepared in Example 7. It can be seen from the figure that the large pores on the fracture surface have disappeared, and there are only small pores. There is an obvious "sea-island" phase separation structure, and the lamellae are also significantly smaller. Furthermore, the fracture pore diameter of Example 7 is smaller than that of Example 11, which may be the reason why the composite material prepared in Example 7 has excellent thermodynamic properties. Figure 2 (d) is a SEM image of the fracture surface of PBAT90-Ser10-3% MPB prepared in Example 10. It can be seen from the figure that the interface between PBAT and sericin becomes difficult to distinguish and the fracture surface is very smooth. This may be the reason why the composite material prepared in Example 10 has excellent mechanical properties.

[0102] The foregoing examples are merely illustrative, used to explain some features of the method described in this invention. The appended claims are intended to claim the broadest possible scope, and the embodiments presented herein are merely illustrative of selected implementations based on combinations of all possible embodiments. Therefore, the applicant intends that the appended claims are not limited by the selection of examples illustrating the features of the invention. Some numerical ranges used in the claims also include sub-ranges within them, and variations within these ranges should also be interpreted as being covered by the appended claims where possible.

Claims

1. A preparation process for a compatibilizer, characterized in that, At least the following steps are included: (1) Add polyester material and solvent to a three-necked flask, heat and stir, introduce nitrogen gas, add the reaction monomer, stir and then add the initiator. After the reaction is complete, the product is obtained. (2) After the product is cooled, the extract is added while stirring, and the product is vacuum filtered and purified to obtain the final product. The reactant monomers are maleic anhydride and glycidyl methacrylate; the weight ratio of maleic anhydride to glycidyl methacrylate is (50~75):(25~75); the reaction temperature is 90~100℃, and the reaction time is 3~5 h; the polyester material is polybutylene adipate terephthalate; the amount of reactant monomers added accounts for 20~40% of the mass percentage of the polyester material.

2. The preparation process of a compatibilizer according to claim 1, characterized in that, The solvent is selected from one or more of xylene, toluene, and decahydronaphthalene.

3. The preparation process of a compatibilizer according to claim 1, characterized in that, The amount of polyester material added is 15~25 g, and the amount of solvent added is 180~220 mL.

4. The preparation process of a compatibilizer according to claim 1, characterized in that, The amount of initiator added is 0.5-3% of the mass of the polyester material.

5. A compatibilizer, characterized in that, It is prepared using the preparation process described in any one of claims 1 to 4.

6. The use of the compatibilizer according to claim 5 in the preparation of a composite material of sericin and PBAT.

Images