Preparation method of high-barrier degradable material

Abstract

This invention discloses a method for preparing a high-barrier biodegradable material, comprising the following steps: A) Raw material pretreatment: Drying solid raw materials separately in a vacuum drying oven at 60-80℃ for 6-12 hours until the moisture content is below 0.05%; B) Melt blending: Mixing the dried raw materials with the remaining raw materials in a specific ratio until homogeneous. This invention significantly improves the barrier properties of the material through the synergistic effect of benzyl glycidyl ether, transesterification modified monomers, 1,4-succinic acid, nano-montmorillonite, and epoxy-modified graphene oxide. A balanced mechanical property is achieved through the rational ratio of polylactic acid and polybutylene adipate-terephthalate, as well as the effects of catalysts, chain extenders, and compatibilizers. The material achieves a degradation rate of 85.2% within 90 days, exhibiting good biodegradability and meeting environmental protection requirements. Through an optimized melt blending process, the material possesses good processing performance and can be molded using conventional plastic processing equipment, facilitating industrial production.

Description

Technical Field

[0001] This invention relates to the field of biodegradable materials technology, specifically to a method for preparing a high-barrier biodegradable material. Background Technology

[0002] With the increasing awareness of environmental protection and the growing emphasis on plastic pollution control in various countries, the development and application of biodegradable packaging materials has become an important direction for industry development. Biodegradable materials can be divided into natural polymer materials (such as starch and cellulose) and biodegradable synthetic materials according to their source. Among them, biodegradable synthetic materials have broad application prospects in the packaging field due to their controllable properties and good processing performance. However, existing biodegradable packaging materials have poor waterproofness and overall strength, which reduces their service life and limits their application scope. Therefore, we propose a method for preparing high-barrier biodegradable materials. Summary of the Invention

[0003] The purpose of this invention is to provide a method for preparing a high-barrier biodegradable material to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, the present invention provides the following technical solution: a method for preparing a high-barrier biodegradable material, comprising the following steps:

[0005] A. Raw material pretreatment: Place the solid raw materials in a vacuum drying oven at 60-80℃ and dry for 6-12 hours to reduce the moisture content to below 0.05%;

[0006] B. Melt blending: The dried raw materials and the remaining raw materials are mixed evenly in proportion, and then fed into a twin-screw extruder for melt blending. The extrusion temperature is 160-200℃ and the screw speed is 200-400r / min to obtain composite material granules.

[0007] C. Granulation and drying: The melt-blended composite material is granulated by a pelletizer and then dried in a vacuum drying oven at 60-80℃ for 4-8 hours to obtain high-barrier biodegradable material granules;

[0008] D. Molding and processing: The dried granules are molded using a blown film machine or injection molding machine to obtain high-barrier biodegradable films or products.

[0009] Preferably, the raw materials in step A consist of benzyl glycidyl ether, transesterification modified monomer, 1,4-succinic acid, catalyst, polylactic acid, polybutylene adipate terephthalate, nano-montmorillonite, epoxy-modified graphene oxide, chain extender, compatibilizer, and antioxidant, with the following weight percentages: benzyl glycidyl ether 10-18 parts, transesterification modified monomer 30-40 parts; 1,4-succinic acid 50-80 parts; catalyst 4-8 parts; polylactic acid 60-80 parts; polybutylene adipate terephthalate 20-40 parts; nano-montmorillonite 3-8 parts; epoxy-modified graphene oxide 2-7 parts; chain extender 4-8 parts; compatibilizer 3-6 parts; antioxidant 2-5 parts.

[0010] Preferably, the catalyst is composed of stannous octoate, stannous chloride, tetrabutyl titanate, calcium carbonate, silicon dioxide, copper oxide, and porous ceramics, with the following weight proportions: 2-8 parts stannous octoate; 5-10 parts stannous chloride; 4-7 parts tetrabutyl titanate; 10-15 parts calcium carbonate; 8-12 parts silicon dioxide; 6-11 parts copper oxide; and 7-12 parts porous ceramics.

[0011] Preferably, the chain extender is composed of 2-imidazolium ketone, adipic acid chloride, amino-terminated polyether, low molecular weight polyoxypropylene diol, epichlorohydrin, ammonium bromide, isocyanate, zinc stearate, 1,2-propanediamine, methyl acrylate, and ethyl methacrylate, with the following weight percentages: 2-imidazolium ketone 7-12 parts; adipic acid chloride 6-10 parts; amino-terminated polyether 5-8 parts; low molecular weight polyoxypropylene diol 25-35 parts; epichlorohydrin 7-12 parts; ammonium bromide 1-3 parts; isocyanate 2-5 parts; zinc stearate 3 parts; 1,2-propanediamine 4-10 parts; methyl acrylate 5-15 parts; and ethyl methacrylate 6-14 parts.

[0012] Preferably, the compatibilizer is composed of ethylene thermoplastic elastomer, glycidyl methacrylate, maleic anhydride-grafted polylactic acid, fatty acid, polyphenylene ether, terephthalic acid, and maleic acid, with the following weight percentages: 7-12 parts ethylene thermoplastic elastomer; 5-10 parts glycidyl methacrylate; 8-15 parts maleic anhydride-grafted polylactic acid; 4-9 parts fatty acid; 6-11 parts polyphenylene ether; 3-8 parts terephthalic acid; and 2-7 parts maleic acid.

[0013] Preferably, the antioxidant is composed of modified tannic acid, thionyl chloride, sodium bicarbonate, phosphite, triethyl phosphite, tetrahydric alcohol, trinonylphenyl phosphite, sodium polyphosphate, fluorapatite, and potassium stearate, with the following weight proportions: modified tannic acid 1-4 parts; thionyl chloride 2-6 parts; sodium bicarbonate 7-12 parts; phosphite 4-8 parts; triethyl phosphite 10-15 parts; tetrahydric alcohol 3-7 parts; trinonylphenyl phosphite 1-3 parts; sodium polyphosphate 2-8 parts; fluorapatite 10-17 parts; and potassium stearate 5-10 parts.

[0014] Preferably, the preparation method of the epoxy-modified graphene oxide is as follows: dispersing graphene oxide in deionized water, adding epichlorohydrin and sodium hydroxide, reacting at 60-80℃ for 4-8 hours, and obtaining epoxy-modified graphene oxide by centrifugation, washing and drying after the reaction.

[0015] Preferably, the nano-montmorillonite has a particle size of 10-50 nm, an interlayer spacing of 1.2-2.5 nm, and a cation exchange capacity of 80-120 mmol / 100g.

[0016] Preferably, in step B, the length-to-diameter ratio of the twin-screw extruder is 40:1-48:1, and the extrusion temperature is controlled in four stages: 160-180℃, 170-190℃, 180-200℃, and 190-210℃.

[0017] Preferably, in step B, nitrogen gas is introduced into the twin-screw extruder to purge the air inside the twin-screw extruder, and then esterification polymerization is carried out under nitrogen protection conditions for 10-30 minutes.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0019] This invention significantly improves the barrier properties of a material through the synergistic effect of benzyl glycidyl ether, transesterified modified monomers, 1,4-succinic acid, nano-montmorillonite, and epoxy-modified graphene oxide. A balanced mechanical property is achieved through the rational ratio of polylactic acid and polybutylene adipate-terephthalate, as well as the action of catalysts, chain extenders, and compatibilizers. The material exhibits a degradation rate of 85.2% within 90 days, demonstrating excellent biodegradability and meeting environmental protection requirements. The optimized melt blending process provides good processing performance, allowing for molding using conventional plastic processing equipment, facilitating industrial production. Furthermore, the raw materials are widely available, the preparation process is simple, and the cost is low, indicating promising market application prospects. Detailed Implementation

[0020] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0021] A method for preparing a high-barrier biodegradable material includes the following steps:

[0022] A. Raw material pretreatment: Place the solid raw materials in a vacuum drying oven at 60-80℃ and dry for 6-12 hours to reduce the moisture content to below 0.05%;

[0023] B. Melt blending: The dried raw materials and the remaining raw materials are mixed evenly in proportion, and then fed into a twin-screw extruder for melt blending. The extrusion temperature is 160-200℃ and the screw speed is 200-400r / min to obtain composite material granules.

[0024] C. Granulation and drying: The melt-blended composite material is granulated by a pelletizer and then dried in a vacuum drying oven at 60-80℃ for 4-8 hours to obtain high-barrier biodegradable material granules;

[0025] D. Molding and processing: The dried granules are molded using a blown film machine or injection molding machine to obtain high-barrier biodegradable films or products.

[0026] The raw materials in step A consist of benzyl glycidyl ether, transesterification modified monomer, 1,4-succinic acid, catalyst, polylactic acid, polybutylene adipate terephthalate, nano-montmorillonite, epoxy-modified graphene oxide, chain extender, compatibilizer, and antioxidant. The weight percentages of these components are as follows: benzyl glycidyl ether 10-18 parts; transesterification modified monomer 30-40 parts; 1,4-succinic acid 50-80 parts; catalyst 4-8 parts; polylactic acid 60-80 parts; polybutylene adipate terephthalate 20-40 parts; nano-montmorillonite 3-8 parts; epoxy-modified graphene oxide 2-7 parts; chain extender 4-8 parts; compatibilizer 3-6 parts; antioxidant 2-5 parts.

[0027] The catalyst is composed of stannous octoate, stannous chloride, tetrabutyl titanate, calcium carbonate, silicon dioxide, copper oxide, and porous ceramics, with the following weight proportions: 2-8 parts stannous octoate; 5-10 parts stannous chloride; 4-7 parts tetrabutyl titanate; 10-15 parts calcium carbonate; 8-12 parts silicon dioxide; 6-11 parts copper oxide; and 7-12 parts porous ceramics.

[0028] The chain extender is composed of 2-imidazolidineone, adipic acid chloride, amino-terminated polyether, low molecular weight polyoxypropylene diol, epichlorohydrin, ammonium bromide, isocyanate, zinc stearate, 1,2-propanediamine, methyl acrylate, and ethyl methacrylate, with the following weight percentages: 2-imidazolidineone 7-12 parts; adipic acid chloride 6-10 parts; amino-terminated polyether 5-8 parts; low molecular weight polyoxypropylene diol 25-35 parts; epichlorohydrin 7-12 parts; ammonium bromide 1-3 parts; isocyanate 2-5 parts; zinc stearate 3 parts; 1,2-propanediamine 4-10 parts; methyl acrylate 5-15 parts; and ethyl methacrylate 6-14 parts.

[0029] The compatibilizer is composed of ethylene thermoplastic elastomer, glycidyl methacrylate, maleic anhydride-grafted polylactic acid, fatty acids, polyphenylene ether, terephthalic acid, and maleic acid, with the following weight proportions: ethylene thermoplastic elastomer 7-12 parts; glycidyl methacrylate 5-10 parts; maleic anhydride-grafted polylactic acid 8-15 parts; fatty acids 4-9 parts; polyphenylene ether 6-11 parts; terephthalic acid 3-8 parts; and maleic acid 2-7 parts.

[0030] The antioxidant is composed of modified tannic acid, thionyl chloride, sodium bicarbonate, phosphite, triethyl phosphite, tetrahydric alcohol, trinonylphenyl phosphite, sodium polyphosphate, fluorapatite, and potassium stearate. The weight percentages of the components are as follows: modified tannic acid 1-4 parts; thionyl chloride 2-6 parts; sodium bicarbonate 7-12 parts; phosphite 4-8 parts; triethyl phosphite 10-15 parts; tetrahydric alcohol 3-7 parts; trinonylphenyl phosphite 1-3 parts; sodium polyphosphate 2-8 parts; fluorapatite 10-17 parts; and potassium stearate 5-10 parts.

[0031] The preparation method of epoxy-modified graphene oxide is as follows: graphene oxide is dispersed in deionized water, epichlorohydrin and sodium hydroxide are added, and the reaction is carried out at 60-80℃ for 4-8 hours. After the reaction is completed, the graphene oxide is obtained by centrifugation, washing and drying.

[0032] The particle size of nano-montmorillonite is 10-50 nm, the interlayer spacing is 1.2-2.5 nm, and the cation exchange capacity is 80-120 mmol / 100 g.

[0033] In step B, the length-to-diameter ratio of the twin-screw extruder is 40:1-48:1, and the extrusion temperature is controlled in four stages: 160-180℃, 170-190℃, 180-200℃, and 190-210℃.

[0034] In step B, nitrogen gas is introduced into the twin-screw extruder to purge the air inside. Then, esterification polymerization is carried out under nitrogen protection for 10-30 minutes.

[0035] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a high-barrier biodegradable material, characterized in that: Includes the following steps: A. Raw material pretreatment: Place the solid raw materials in a vacuum drying oven at 60-80℃ and dry for 6-12 hours to reduce the moisture content to below 0.05%; B. Melt blending: The dried raw materials and the remaining raw materials are mixed evenly in proportion, and then fed into a twin-screw extruder for melt blending. The extrusion temperature is 160-200℃ and the screw speed is 200-400r / min to obtain composite material granules. C. Granulation and drying: The melt-blended composite material is granulated by a pelletizer and then dried in a vacuum drying oven at 60-80℃ for 4-8 hours to obtain high-barrier biodegradable material granules; D. Molding and processing: The dried granules are molded using a blown film machine or injection molding machine to obtain high-barrier biodegradable films or products.

2. The method for preparing a high-barrier biodegradable material according to claim 1, characterized in that: The raw materials in step A consist of benzyl glycidyl ether, transesterification modified monomer, 1,4-succinic acid, catalyst, polylactic acid, polybutylene adipate terephthalate, nano-montmorillonite, epoxy-modified graphene oxide, chain extender, compatibilizer, and antioxidant. The weight percentages of these components are as follows: benzyl glycidyl ether 10-18 parts; transesterification modified monomer 30-40 parts; 1,4-succinic acid 50-80 parts; catalyst 4-8 parts; polylactic acid 60-80 parts; polybutylene adipate terephthalate 20-40 parts; nano-montmorillonite 3-8 parts; epoxy-modified graphene oxide 2-7 parts; chain extender 4-8 parts; compatibilizer 3-6 parts; antioxidant 2-5 parts.

3. The method for preparing a high-barrier biodegradable material according to claim 2, characterized in that: The catalyst is composed of stannous octoate, stannous chloride, tetrabutyl titanate, calcium carbonate, silicon dioxide, copper oxide, and porous ceramics, with the following weight proportions: 2-8 parts stannous octoate; 5-10 parts stannous chloride; 4-7 parts tetrabutyl titanate; 10-15 parts calcium carbonate; 8-12 parts silicon dioxide; 6-11 parts copper oxide; and 7-12 parts porous ceramics.

4. The method for preparing a high-barrier biodegradable material according to claim 2, characterized in that: The chain extender is composed of 2-imidazolium ketone, adipic acid chloride, amino-terminated polyether, low molecular weight polyoxypropylene diol, epichlorohydrin, ammonium bromide, isocyanate, zinc stearate, 1,2-propanediamine, methyl acrylate, and ethyl methacrylate, with the following weight percentages: 2-imidazolium ketone 7-12 parts; adipic acid chloride 6-10 parts; amino-terminated polyether 5-8 parts; low molecular weight polyoxypropylene diol 25-35 parts; epichlorohydrin 7-12 parts; ammonium bromide 1-3 parts; isocyanate 2-5 parts; zinc stearate 3 parts; 1,2-propanediamine 4-10 parts; methyl acrylate 5-15 parts; and ethyl methacrylate 6-14 parts.

5. The method for preparing a high-barrier biodegradable material according to claim 2, characterized in that: The compatibilizer is composed of ethylene thermoplastic elastomer, glycidyl methacrylate, maleic anhydride-grafted polylactic acid, fatty acids, polyphenylene ether, terephthalic acid, and maleic acid, with the following weight proportions: 7-12 parts ethylene thermoplastic elastomer; 5-10 parts glycidyl methacrylate; 8-15 parts maleic anhydride-grafted polylactic acid; 4-9 parts fatty acids; 6-11 parts polyphenylene ether; 3-8 parts terephthalic acid; and 2-7 parts maleic acid.

6. The method for preparing a high-barrier biodegradable material according to claim 2, characterized in that: The antioxidant is composed of modified tannic acid, thionyl chloride, sodium bicarbonate, phosphite, triethyl phosphite, tetrahydric alcohol, trinonylphenyl phosphite, sodium polyphosphate, fluorapatite, and potassium stearate, with the following weight proportions: 1-4 parts modified tannic acid; 2-6 parts thionyl chloride; and 7-12 parts sodium bicarbonate. 4-8 parts of phosphite; 10-15 parts of triethyl phosphite; 3-7 parts of tetrahydric alcohol; 1-3 parts of trinonylphenyl phosphite; 2-8 parts of sodium polyphosphate; 10-17 parts of fluorapatite; 5-10 parts of potassium stearate.

7. The method for preparing a high-barrier biodegradable material according to claim 2, characterized in that: The preparation method of the epoxy-modified graphene oxide is as follows: dispersing graphene oxide in deionized water, adding epichlorohydrin and sodium hydroxide, reacting at 60-80℃ for 4-8 hours, and obtaining epoxy-modified graphene oxide by centrifugation, washing and drying after the reaction.

8. The method for preparing a high-barrier biodegradable material according to claim 2, characterized in that: The nano-montmorillonite has a particle size of 10-50 nm, an interlayer spacing of 1.2-2.5 nm, and a cation exchange capacity of 80-120 mmol / 100g.

9. The method for preparing a high-barrier biodegradable material according to claim 1, characterized in that: In step B, the length-to-diameter ratio of the twin-screw extruder is 40:1-48:1, and the extrusion temperature is controlled in four stages: 160-180℃, 170-190℃, 180-200℃, and 190-210℃.

10. The method for preparing a high-barrier biodegradable material according to claim 1, characterized in that: In step B, nitrogen gas is introduced into the twin-screw extruder to purge the air inside, and then esterification polymerization is carried out under nitrogen protection for 10-30 minutes.