Epoxy chain extender based on vinyl polymerization, preparation method and application

Abstract

The invention discloses an epoxy chain extender based on vinyl polymerization as well as a preparation method and application thereof. The preparation method of the epoxy chain extender comprises the following steps: S1, preparing acetylated hydroxyethyl methylacrylate; s2, in an inert atmosphere, mixing glycidyl methacrylate, styrene, acetylated hydroxyethyl methacrylate, an initiator and a molecular regulator in tetrahydrofuran; and S3, adding the mixed solution in S2 into ethanol for reaction, and filtering, washing and drying the reaction product to obtain the epoxy chain extender based on vinyl polymerization. By introducing the third monomer and modifying the third monomer, the molecular weight of the produced copolymer is reduced, the opening efficiency of an epoxy group is increased, and the epoxy value of the copolymer is increased.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer materials, and particularly to an epoxy chain extender based on vinyl polymerization, a preparation method and an application thereof. Background Art

[0002] At present, green, low-carbon and environmental protection have become hot topics in today's society. Due to its structural characteristics, epoxy chain extenders have broad application prospects in the field of polymer materials. Its epoxy groups have high reactivity and can react with a variety of functional groups, thereby effectively increasing the molecular weight of the polymer and improving its mechanical properties and processing properties. However, traditional epoxy chain extenders such as glycidyl methacrylate (GMA), although having high reactivity, are expensive and prone to self-polymerization reactions, which limit their large-scale industrial applications. The present invention has successfully prepared a new type of epoxy chain extender by introducing inexpensive styrene (St) and 2-hydroxyethyl methacrylate (HEMA). This chain extender has the advantages of low molecular weight, high chain extension efficiency and high epoxy value, and is expected to solve the problems existing in traditional epoxy chain extenders and provide new ideas for the development of polymer materials.

[0003] Using a chain extender is a way to improve the properties and processability of polymers. During the melting process of polymer reactants, adding a chain extender, under the condition of blending, the chain extender reacts with the active groups at the ends of polymer molecules to form a "bridge". The chain extender undergoes coupling and branching reactions at the broken points of different polymer molecular chains, thereby further increasing the molecular chain length and improving the melt strength and processing stability of the copolymer.

[0004] Common epoxy chain extenders are copolymers of styrene and GMA. The GMA-based chain extension system that is widely used in industry at present has obvious technical limitations: First, the raw material cost of GMA monomers is high and self-polymerization side reactions are prone to occur during the reaction process, resulting in a decrease in the effective chain extension efficiency. Second, existing st-GMA copolymeric chain extenders generally have the defects of low epoxy value and insufficient functional group density. To achieve an ideal melt index (and processing stability often requires an increase in the usage amount, which increases the production cost. Therefore, developing a new chain extension system with high epoxy value, low molecular weight characteristics and economy has become a key topic that urgently needs to be broken through in the field of green modification technology of polymer materials. Summary of the Invention

[0005] Based on the technical problems existing in the background art, the present invention proposes an epoxy chain extender based on vinyl polymerization, a preparation method and an application thereof. By introducing a third monomer and modifying the third monomer, the molecular weight of the produced copolymer is reduced, the opening efficiency of epoxy groups is increased, and its epoxy value is improved.

[0006] The preparation method of the epoxy chain extender based on vinyl polymerization proposed by the present invention is as follows:

[0007] S1: Preparation of Hydroxyethyl Acrylate Methacrylate Acetate

[0008] S2: Under an inert atmosphere, glycidyl methacrylate, styrene, hydroxyethyl acrylate methacrylate acetate, an initiator, and a molecular regulator are mixed in tetrahydrofuran

[0009] S3: The mixture obtained in S2 is added to ethanol for reaction. After the reaction, the product is filtered, washed, and dried to obtain an epoxy chain extender based on vinyl polymerization

[0010] Preferably, the method for preparing hydroxyethyl acrylate methacrylate acetate comprises the following steps

[0011] S11: Dissolve hydroxyethyl acrylate methacrylate in ethyl acetate

[0012] S12: Add 4-dimethylaminopyridine and acetic anhydride to the solution obtained in S11 for reaction

[0013] S13: After the reaction, wash, dry, and concentrate to obtain hydroxyethyl acrylate methacrylate acetate

[0014] Preferably, the mass ratio of hydroxyethyl acrylate methacrylate, 4-dimethylaminopyridine, and acetic anhydride is 40-50:1:60-70

[0015] Preferably, the reaction temperature in S12 is 20-30°C, and the reaction time is 8-16 h

[0016] Preferably, the mass ratio of glycidyl methacrylate, styrene, hydroxyethyl acrylate methacrylate acetate, an initiator, and a molecular regulator is 100:50-70:30-50:0.5-1:0.4-0.8

[0017] Preferably, the initiator is one or more of azobisisobutyronitrile, benzoyl peroxide, and cumene hydroperoxide; the molecular regulator is one or more of n-dodecyl mercaptan, carbon tetrachloride, and α-methylstyrene dimer

[0018] Preferably, the reaction temperature in S3 is 65-75°C, and the reaction time is 8-10 h

[0019] An epoxy chain extender based on vinyl polymerization proposed by the present invention is prepared by the above preparation method

[0020] A polymer material proposed by the present invention is prepared by melt extrusion of polybutylene adipate terephthalate, polylactic acid, and the above epoxy chain extender

[0021] Advantageous technical effects of the present invention

[0022] (1) Compared with the application of ethyl methacrylate (EMA) only as an inert diluent monomer in other inventions, the present invention selects 2-hydroxyethyl methacrylate (HEMA) with a hydroxyl active site as the functional monomer. The acetylation treatment not only retains the stereostructure characteristics of HEMA but also protects the hydroxyl group to make the reaction controllable.

[0023] (2) Compared with the chain extender prepared using ethyl methacrylate (EMA) as the monomer in other inventions, which only adjusts the molecular weight and improves the processing performance, using acetylated 2-hydroxyethyl methacrylate (HEMA) as the reaction monomer can form a branched or crosslinked structure, thereby improving the melt strength, impact resistance, etc. of the polymer and expanding its scope of use.

[0024] (3) By acetylating 2-hydroxyethyl methacrylate, the present invention can reduce the self-polymerization rate of HEMA, effectively reduce the molecular weight of the chain extender, make its dispersion degree better in the polymer, and the chain extension effect is more obvious.

[0025] (4) The chain extender of the present invention has higher reaction activity and better compatibility, and can effectively improve the mechanical properties, thermal properties and processing properties of the polymer material; and by changing the molecular weight of the chain extender, its diffusion ability in the polymer material can be improved, so that the effective groups are more evenly distributed and the material properties are improved. This chain extender has broad application prospects in the fields of rubber, plastics, coatings, etc. Description of the Drawings

[0026] Figure 1 It is the preparation flow chart of the epoxy chain extender based on vinyl polymerization proposed by the present invention;

[0027] Figure 2 It is the TG-DSC diagram of the thermal analysis of the chain extender PGHS proposed by the present invention;

[0028] Figure 3 It is the TDSC diagram of the thermal analysis of the chain extender PGHS proposed by the present invention;

[0029] Figure 4 It is the NMR spectrum diagram of acetylated HEMA proposed by the present invention;

[0030] Figure 5 It is the IR analysis diagram of the chain extender PGHS proposed by the present invention;

[0031] Figure 6 It is the tensile properties of different PLA / PBAT blend systems proposed by the present invention. Detailed Embodiments

[0032] The present invention will be further explained below with specific embodiments.

[0033] Example 1

[0034] The 2 - hydroxyethyl methacrylate was acetylated. 26 g of 2 - hydroxyethyl methacrylate was dissolved in 50 ml of ethyl acetate, then 0.61 g of 4 - dimethylaminopyridine and 28.4 ml of acetic anhydride were added. After stirring at room temperature for 12 hours, the reaction was quenched with water. Then water, diluted aqueous sodium bicarbonate solution, and water were successively added to wash away the alkali and salt content. The organic layer was dried with anhydrous magnesium sulfate, filtered, and concentrated under reduced pressure to obtain acetylated 2 - hydroxyethyl methacrylate.

[0035] The styrene and glycidyl methacrylate were alkali - washed to remove the inhibitors therein. Then 5 g of styrene, 25 g of glycidyl methacrylate, and 20 g of acetylated 2 - hydroxyethyl methacrylate were mixed in a reaction vessel containing 100 g of tetrahydrofuran. 0.4 g of azobisisobutyronitrile and 0.3 g of n - dodecyl mercaptan were added to the reaction vessel. After evacuating the reaction vessel, it was protected with an inert gas. Then it was placed in an oil bath, and the oil bath temperature was adjusted to 75 °C. After rapid stirring for 8 h, the reaction was completed.

[0036] After the reaction was completed and cooled, the cooled reactant was slowly dropped into an ethanol solution with 10 times its volume and stirred for 10 minutes. After vacuum filtration under reduced pressure, a sticky solid was precipitated. The precipitated sticky solid was washed thoroughly with deionized water to remove the monomers and dispersants attached to the surface. After drying, the epoxy chain extender, denoted as PGHS - 1, was obtained.

[0037] Example 2

[0038] The 2 - hydroxyethyl methacrylate was acetylated. 26 g of 2 - hydroxyethyl methacrylate was dissolved in 50 ml of ethyl acetate, then 0.61 g of 4 - dimethylaminopyridine and 28.4 ml of acetic anhydride were added. After stirring at room temperature for 12 hours, the reaction was quenched with water. Then water, diluted aqueous sodium bicarbonate solution, and water were successively added to wash away the alkali and salt content. The organic layer was dried with anhydrous magnesium sulfate, filtered, and concentrated under reduced pressure to obtain acetylated 2 - hydroxyethyl methacrylate.

[0039] The styrene and glycidyl methacrylate were alkali - washed to remove the inhibitors therein. Then 10 g of styrene, 25 g of glycidyl methacrylate, and 15 g of acetylated 2 - hydroxyethyl methacrylate were mixed in a reaction vessel containing 100 g of tetrahydrofuran. 0.4 g of azobisisobutyronitrile and 0.3 g of n - dodecyl mercaptan were added to the reaction vessel. After evacuating the reaction vessel, it was protected with an inert gas. Then it was placed in an oil bath, and the oil bath temperature was adjusted to 75 °C. After rapid stirring for 8 h, the reaction was completed.

[0040] After the reaction was completed and the temperature was lowered, the cooled reactants were slowly added dropwise to an ethanol solution with a volume 10 times that of the reactants and stirred for 10 minutes. After vacuum filtration under reduced pressure, a sticky solid was precipitated; the precipitated sticky solid was washed thoroughly with deionized water to remove the monomers and dispersants adhering to the surface, and after drying, an epoxy chain extender was obtained, denoted as PGHS-2.

[0041] Example 3

[0042] Hydroxyethyl methacrylate was acetylated. 26 g of hydroxyethyl methacrylate was dissolved in 50 ml of ethyl acetate, and then 0.61 g of 4-dimethylaminopyridine and 28.4 ml of acetic anhydride were added. After stirring at room temperature for 12 hours, the reaction was quenched with water. Then, water, diluted aqueous sodium bicarbonate solution, and water were added in sequence to wash away the alkali and salt content. Then, the organic layer was dried with anhydrous magnesium sulfate, filtered, and concentrated under reduced pressure to obtain acetylated hydroxyethyl methacrylate.

[0043] Styrene and glycidyl methacrylate were subjected to alkali washing to remove the inhibitors therein; then, 20 g of styrene, 25 g of glycidyl methacrylate, and 5 g of acetylated hydroxyethyl methacrylate were mixed in a reaction vessel containing 100 g of tetrahydrofuran. 0.4 g of azobisisobutyronitrile and 0.3 g of n-dodecyl mercaptan were added to the reaction vessel. After evacuating the reaction vessel, it was protected with an inert gas, and then it was placed in an oil bath. The oil bath temperature was adjusted to 75 °C, and the reaction was completed after rapid stirring for 8 h.

[0044] After the reaction was completed and the temperature was lowered, the cooled reactants were slowly added dropwise to an ethanol solution with a volume 10 times that of the reactants and stirred for 10 minutes. After vacuum filtration under reduced pressure, a sticky solid was precipitated; the precipitated sticky solid was washed thoroughly with deionized water to remove the monomers and dispersants adhering to the surface, and after drying, an epoxy chain extender was obtained, denoted as PGHS-3.

[0045] Example 4

[0046] Hydroxyethyl methacrylate was acetylated. 26 g of hydroxyethyl methacrylate was dissolved in 50 ml of ethyl acetate, and then 0.61 g of 4-dimethylaminopyridine and 28.4 ml of acetic anhydride were added. After stirring at room temperature for 12 hours, the reaction was quenched with water. Then, water, diluted aqueous sodium bicarbonate solution, and water were added in sequence to wash away the alkali and salt content. Then, the organic layer was dried with anhydrous magnesium sulfate, filtered, and concentrated under reduced pressure to obtain acetylated hydroxyethyl methacrylate.

[0047] Wash styrene and glycidyl methacrylate with alkali to remove the inhibitor therein; then mix 15 g of styrene, 25 g of glycidyl methacrylate and 10 g of acetylated hydroxyethyl methacrylate in a reaction vessel containing 100 g of tetrahydrofuran. Add 0.4 g of azobisisobutyronitrile and 0.3 g of n-dodecyl mercaptan to the reaction vessel. After evacuating the reaction vessel, carry out inert gas protection, and then place it in an oil bath. Adjust the oil bath temperature to 75 °C and stir rapidly for 8 h to complete the reaction.

[0048] After the reaction is completed and the temperature is lowered, slowly drop the cooled reactant into an ethanol solution with 10 times its volume and stir for 10 minutes. After vacuum filtration under reduced pressure, a sticky solid is precipitated; wash the precipitated sticky solid thoroughly with deionized water to remove the monomers and dispersants attached to the surface, and dry it to obtain an epoxy chain extender, denoted as PGHS-4.

[0049] Example 5

[0050] Acetylate hydroxyethyl methacrylate. Dissolve 26 g of hydroxyethyl methacrylate in 50 ml of ethyl acetate, then add 0.61 g of 4-dimethylaminopyridine and 28.4 ml of acetic anhydride. Stir at room temperature for 12 hours to complete the reaction, then quench with water. Then add water, diluted aqueous sodium bicarbonate solution, and water in sequence to wash away the alkali and salt content. Then dry the organic layer with anhydrous magnesium sulfate, filter, and concentrate under reduced pressure to obtain acetylated hydroxyethyl methacrylate.

[0051] Wash styrene and glycidyl methacrylate with alkali to remove the inhibitor therein; then mix 27 g of styrene, 5 g of glycidyl methacrylate and 18 g of acetylated hydroxyethyl methacrylate in a reaction vessel containing 100 g of tetrahydrofuran. Add 0.4 g of azobisisobutyronitrile and 0.3 g of n-dodecyl mercaptan to the reaction vessel. After evacuating the reaction vessel, carry out inert gas protection, and then place it in an oil bath. Adjust the oil bath temperature to 75 °C and stir rapidly for 8 h to complete the reaction.

[0052] After the reaction is completed and the temperature is lowered, slowly drop the cooled reactant into an ethanol solution with 10 times its volume and stir for 10 minutes. After vacuum filtration under reduced pressure, a sticky solid is precipitated; wash the precipitated sticky solid thoroughly with deionized water to remove the monomers and dispersants attached to the surface, and dry it to obtain an epoxy chain extender, denoted as PGHS-5.

[0053] Example 6

[0054] The hydroxyethyl methacrylate was acetylated. 26 g of hydroxyethyl methacrylate was dissolved in 50 ml of ethyl acetate, then 0.61 g of 4-dimethylaminopyridine and 28.4 ml of acetic anhydride were added. After stirring at room temperature for 12 hours, the reaction was quenched with water. Then water, diluted aqueous sodium bicarbonate solution, and water were added successively to wash away the alkali and salt content. The organic layer was then dried over anhydrous magnesium sulfate, filtered, and concentrated under reduced pressure to obtain acetylated hydroxyethyl methacrylate.

[0055] The styrene and glycidyl methacrylate were washed with alkali to remove the inhibitor therein. Then 24 g of styrene, 10 g of glycidyl methacrylate, and 16 g of acetylated hydroxyethyl methacrylate were mixed in a reaction vessel containing 100 g of tetrahydrofuran. 0.4 g of azobisisobutyronitrile and 0.3 g of n-dodecyl mercaptan were added to the reaction vessel. After evacuating the reaction vessel, it was protected with an inert gas. Then it was placed in an oil bath, and the oil bath temperature was adjusted to 75 °C. The reaction was completed after rapid stirring for 8 h.

[0056] After the reaction was completed and cooled down, the cooled reactant was slowly added dropwise to an ethanol solution with 10 times its volume and stirred for 10 minutes. After vacuum filtration under reduced pressure, a sticky solid was precipitated. The precipitated sticky solid was washed thoroughly with deionized water to remove the monomers and dispersants attached to the surface. After drying, the epoxy chain extender was obtained and denoted as PGHS-6.

[0057] Example 7

[0058] The hydroxyethyl methacrylate was acetylated. 26 g of hydroxyethyl methacrylate was dissolved in 50 ml of ethyl acetate, then 0.61 g of 4-dimethylaminopyridine and 28.4 ml of acetic anhydride were added. After stirring at room temperature for 12 hours, the reaction was quenched with water. Then water, diluted aqueous sodium bicarbonate solution, and water were added successively to wash away the alkali and salt content. The organic layer was then dried over anhydrous magnesium sulfate, filtered, and concentrated under reduced pressure to obtain acetylated hydroxyethyl methacrylate.

[0059] The styrene and glycidyl methacrylate were washed with alkali to remove the inhibitor therein. Then 21 g of styrene, 15 g of glycidyl methacrylate, and 14 g of acetylated hydroxyethyl methacrylate were mixed in a reaction vessel containing 100 g of tetrahydrofuran. 0.4 g of azobisisobutyronitrile and 0.3 g of n-dodecyl mercaptan were added to the reaction vessel. After evacuating the reaction vessel, it was protected with an inert gas. Then it was placed in an oil bath, and the oil bath temperature was adjusted to 75 °C. The reaction was completed after rapid stirring for 8 h.

[0060] After the reaction was completed and the temperature was lowered, the cooled reactants were slowly added dropwise to an ethanol solution with a volume 10 times that of the reactants and stirred for 10 minutes. After vacuum filtration under reduced pressure, a sticky solid was precipitated. The precipitated sticky solid was washed thoroughly with deionized water to remove the monomers and dispersants adhering to the surface, and then dried to obtain an epoxy chain extender, denoted as PGHS-7.

[0061] Example 8

[0062] Hydroxyethyl methacrylate was acetylated. 26 g of hydroxyethyl methacrylate was dissolved in 50 ml of ethyl acetate, then 0.61 g of 4-dimethylaminopyridine and 28.4 ml of acetic anhydride were added. After stirring at room temperature for 12 hours, the reaction was quenched with water, and then water, diluted aqueous sodium bicarbonate solution, and water were successively added to wash away the alkali and salt contents. Then the organic layer was dried over anhydrous magnesium sulfate, filtered, and concentrated under reduced pressure to obtain acetylated hydroxyethyl methacrylate.

[0063] Styrene and glycidyl methacrylate were subjected to alkali washing to remove the inhibitors therein. Then 18 g of styrene, 20 g of glycidyl methacrylate, and 12 g of acetylated hydroxyethyl methacrylate were mixed in a reaction vessel containing 100 g of tetrahydrofuran. 0.4 g of azobisisobutyronitrile and 0.3 g of n-dodecyl mercaptan were added to the reaction vessel. After evacuating the reaction vessel, it was protected with an inert gas, and then placed in an oil bath. The oil bath temperature was adjusted to 75 °C, and the reaction was completed after rapid stirring for 8 h.

[0064] After the reaction was completed and the temperature was lowered, the cooled reactants were slowly added dropwise to an ethanol solution with a volume 10 times that of the reactants and stirred for 10 minutes. After vacuum filtration under reduced pressure, a sticky solid was precipitated. The precipitated sticky solid was washed thoroughly with deionized water to remove the monomers and dispersants adhering to the surface, and then dried to obtain an epoxy chain extender, denoted as PGHS-8.

[0065] Example 9

[0066] 350 g of PLA and 150 g of PBAT were weighed and uniformly mixed with 0.25 g of PGHS-4 in a mixer. Then, they were extruded and pelletized using a twin-screw extruder to obtain PLA / PBAT blend pellets. The twin-screw extrusion temperature was set at 180, 190, 190, 180 °C, and the main machine speed was set at 150 r / min. After drying the prepared pellets in an oven at 60 °C for 12 h, they were injection molded into standard specimens at an injection molding temperature of 180 °C and an injection molding pressure of 0.6 MPa, denoted as Composite Material-1.

[0067] Example 10

[0068] Weigh 350 g of PLA and 150 g of PBAT, and place them together with 0.5 g of PGHS-4 in a mixer for uniform mixing. Then, use a twin-screw extruder to extrude and granulate the mixture to obtain the PLA / PBAT blend system pellets. The twin-screw extrusion temperature is set at 180, 190, 190, 180 °C, and the main machine speed is set at 150 r / min. After drying the prepared pellets in an oven at 60 °C for 12 h, injection mold them into standard specimens at an injection temperature of 180 °C and an injection pressure of 0.6 MPa, denoted as Composite Material-2.

[0069] Comparative Example 1

[0070] Weigh 350 g of PLA and 150 g of PBAT, and place them together with 0.5 g of chain extender ADR (commercially available, purchased from BASF Group) in a mixer for uniform mixing. Then, use a twin-screw extruder to extrude and granulate the mixture to obtain the PLA / PBAT blend system pellets. The twin-screw extrusion temperature is set at 180, 190, 190, 180 °C, and the main machine speed is set at 150 r / min. After drying the prepared pellets in an oven at 60 °C for 12 h, injection mold them into standard specimens at an injection temperature of 180 °C and an injection pressure of 0.6 MPa, denoted as Composite Material-3.

[0071] The present invention conducts differential scanning calorimetry analysis on the epoxy chain extenders prepared in Examples 1-4, compares and selects the optimal monomer ratio as the preparation scheme of the chain extender. Its DSC and TG curves are as Figure 2 、 Figure 3 shown. It can be analyzed from Figure 2 、 Figure 3 that when the usage ratio of the monomer is that of Example 4, the thermal stability of the chain extender is the highest.

[0072] The present invention determines the epoxy value and epoxy equivalent of the epoxy chain extenders provided in Examples 1-7 through GB / T 1677-2008 "Determination of Epoxy Value of Plasticizers". The results are shown in Table 1.

[0073] Table 1 Number-average Molecular Weight and Epoxy Equivalent of Samples

[0074] sample epoxy value epoxy equivalent PGHS-1 284.96 0.351 PGHS-2 281.52 0.355 PGHS-3 283.51 0.352 PGHS-4 279.85 0.357 PGHS-5 986.32 0.101 PGHS-6 833.45 0.120 PGHS-7 480.17 0.208 PGHS-8 337.95 0.296

[0075] It can be found from Table 1 that the difference between PGHS4 - PGHS8 lies in the different usage amounts of GMA, and with the increase in the usage amount of GMA, the epoxy value will decrease accordingly. The size of the epoxy value has an important impact on the performance of PGHS. A lower epoxy value will increase the consumption of the chain extender and cause waste. Therefore, under the condition of controlling the usage amount of GMA unchanged, change the ratio of styrene to hydroxyethyl methacrylate acetate to prepare PGHS1 - PGHS4, and compare their thermal properties.

[0076] In the present invention, HEMA is acetylated. Acetic anhydride undergoes a nucleophilic addition reaction with the hydroxyl group of HEMA, replacing the hydroxyl group in HEMA with an acetyl group to generate acetylated HEMA. This can effectively prevent the self-polymerization of HEMA from affecting the performance of the product. Moreover, the use of anhydrous acetic anhydride results in mild reaction conditions and high product purity.

[0077] The nuclear magnetic resonance hydrogen spectrum analysis of acetylated HEMA was carried out, and the results are as Figure 4 shown. Figure 4 It is the NMR spectrum of Ac-HEMA. In this NMR spectrum, the peaks corresponding to 1 and 5 are at 1.89 and 2.02 ppm respectively. The positions of the two hydrogens at 2 are at 6.08 and 5.54 ppm. The peaks corresponding to 3 and 4 are at 4.28 ppm. From the above, it can be concluded that HEMA has been acetylated, and the hydroxyl group in HEMA has been replaced by an acetyl group.

[0078] The infrared detection and analysis of the chain extender PGHS-4 prepared in Example 4 of the present invention were carried out, and the results are as Figure 5 shown, where 1729 cm -1 is the stretching vibration peak of the carbonyl group, corresponding to the GMA and HEMA structural units in the copolymer. 907 cm -1 is the characteristic peak of the epoxy group, corresponding to the GMA structural unit in the copolymer. 1495 cm -1 , 1456 cm -1 are the benzene ring skeleton vibration peaks, corresponding to the structural unit of the copolymer st. 3200 - 3700 cm -1 is the broad peak of the stretching vibration of the hydroxyl group, corresponding to the structural unit of HEMA in the copolymer. From the above, it can be seen that the synthesis of the PGHS chain extender with epoxy ring functional groups was successful.

[0079] The melt index test and the terminal amino group content test were carried out on the pure PLA / PBAT samples and the composites 1 - 3. The results are shown in Table 2. It can be seen from Table 2 that after the melt blending of PGHS and PLA / PBAT, both the melt index and the terminal amino group content decreased significantly. This is because the epoxy group in PGHS undergoes a ring-opening reaction with the terminal carboxyl group in the PLA / PBAT system, thereby increasing the molecular chain length of PLA / PBAT and reducing the terminal carboxyl group content of PLA / PBAT. Moreover, since the content of epoxy functional groups in PGHS is relatively high, its chain extension effect is more obvious, and it can more effectively improve the thermal stability and strength of the PLA / PBAT system.

[0080] Table 2 Melt Index and Terminal Amino Group Content of Samples

[0081]

[0082]

[0083] Tensile property tests were conducted on pure PLA / PBAT samples and Composites 1-3, and the results are as Figure 6 shown. It can be seen from Figure 6 that when a chain extender is added, the tensile strength of the PAL / PBAT system is significantly improved. This is because the bonding effect of the chain extender increases the compatibility between PLA and PBAT. At the same time, after comparing the self-made chain extender PGHS with the commercially available chain extender ADR, it can be found that the tensile property of the PLA / PBAT blend system with the addition of the chain extender PGHS is stronger than that of the ADR chain extender. It can also be found that the fracture growth rate of the PLA / PBAT system after adding the chain extender has also been significantly improved, probably only because the generated PLA-PGHS-PBAT copolymer acts as a compatibilizer, making the mechanical properties of the PLA / PBAT system significantly enhanced.

[0084] Although the embodiments of the present application have been shown and described, for those of ordinary skill in the art, it can be understood that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present application. The scope of the present application is defined by the appended claims and their equivalents, and all of them should be included within the protection scope of the present application.

Claims

1. Preparation method of epoxy chain extender based on vinyl polymerization, characterized in that, The method steps are as follows: S1: Preparation of acetylated hydroxyethyl methacrylate; S2: Under an inert atmosphere, glycidyl methacrylate, styrene, acetylated hydroxyethyl methacrylate, an initiator, and a molecular regulator are mixed in tetrahydrofuran; S3: The mixture of S2 is added to ethanol for reaction, and the reaction product is filtered, washed, and dried to obtain an epoxy chain extender based on vinyl polymerization.

2. The preparation method of the epoxy chain extender based on vinyl polymerization according to claim 1, characterized in that, The method steps for the preparation of acetylated hydroxyethyl methacrylate are as follows: S11: Dissolve hydroxyethyl methacrylate in ethyl acetate; S12: Add 4-dimethylaminopyridine and acetic anhydride to the solution of S11 for reaction; S13: After the reaction, it is washed, dried, and concentrated to obtain acetylated hydroxyethyl methacrylate.

3. The preparation method of the epoxy chain extender based on vinyl polymerization according to claim 2, wherein, The mass ratio of hydroxyethyl methacrylate, 4-dimethylaminopyridine, and acetic anhydride is 40-50:1:60-70.

4. The preparation method of the epoxy chain extender based on vinyl polymerization according to claim 2, wherein, The reaction temperature in S12 is 20-30°C, and the reaction time is 8-16 h.

5. The preparation method of the epoxy chain extender based on vinyl polymerization according to claim 1, characterized in that, The mass ratio of glycidyl methacrylate, styrene, acetylated hydroxyethyl methacrylate, an initiator, and a molecular regulator is 100:50-70:30-50:0.5-1:0.4-0.

8.

6. The preparation method of the epoxy chain extender based on vinyl polymerization according to claim 1, wherein, The initiator is one or more of azobisisobutyronitrile, benzoyl peroxide, and cumene hydroperoxide; the molecular regulator is one or more of n-dodecyl mercaptan, carbon tetrachloride, and α-methylstyrene dimer.

7. The preparation method of the epoxy chain extender based on vinyl polymerization according to claim 1, characterized in that, The reaction temperature in S3 is 65-75°C, and the reaction time is 8-10 h.

8. An epoxy chain extender based on vinyl polymerization, characterized in that, Prepared by the preparation method described in any one of claims 1-7.

9. A polymer material, characterized in that, Prepared by melt extrusion of polybutylene adipate terephthalate, polylactic acid, and the epoxy chain extender described in claim 8.

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