阅读说明：本技术 淀粉填充pla/pbat全生物降解复合材料及其制备方法 (Starch filled PLA/PBAT full-biodegradable composite material and preparation method thereof ) 是由 梁俊雅 陈军 王凡 李双利 田洪池 于 2019-11-13 设计创作，主要内容包括：本发明提出一种淀粉填充PLA/PBAT全生物降解复合材料及其制备方法,属于高分子材料领域,能够解决聚乳酸韧性差、脆性易断的问题,又能解决淀粉难加工、与PLA/PBAT树脂相容性差等技术问题。该淀粉填充PLA/PBAT全生物降解复合材料按重量份计包括聚乳酸5-90份、聚己二酸/对苯二甲酸丁二酯10-90份、淀粉10-50份、增塑剂2-15份、偶联剂0.1-5份、分散剂0.1-0.5份、增容剂0.1-1份和抗氧剂0.1-0.5份。本发明能够应用于淀粉填充PLA/PBAT全生物降解复合材料的制作中。(The invention provides a starch filled PLA/PBAT full-biodegradable composite material and a preparation method thereof, belongs to the field of high polymer materials, and can solve the problems of poor toughness and brittleness and easy breaking of polylactic acid, and also can solve the technical problems of difficult processing of starch, poor compatibility with PLA/PBAT resin and the like. The starch filled PLA/PBAT full-biodegradable composite material comprises, by weight, 5-90 parts of polylactic acid, 10-90 parts of poly adipic acid/polybutylene terephthalate, 10-50 parts of starch, 2-15 parts of a plasticizer, 0.1-5 parts of a coupling agent, 0.1-0.5 part of a dispersing agent, 0.1-1 part of a compatibilizer and 0.1-0.5 part of an antioxidant. The invention can be applied to the preparation of starch-filled PLA/PBAT full-biodegradable composite materials.)

1. The starch filled PLA/PBAT full-biodegradable composite material is characterized by comprising the following components in parts by weight:

5-90 parts of polylactic acid, 10-90 parts of poly (butylene adipate)/terephthalate, 10-50 parts of starch, 2-15 parts of plasticizer, 0.1-5 parts of coupling agent, 0.1-0.5 part of dispersant, 0.1-1 part of compatibilizer and 0.1-0.5 part of antioxidant.

2. The composite material of claim 1, wherein the polylactic acid is at least one of a dextrolactic acid, a levolactic acid, a racemic polylactic acid, and mixtures thereof.

3. The composite of claim 1, wherein the starch is at least one of native starch, acetate starch, and acetyl starch, wherein the native starch comprises at least one of corn starch, wheat starch, barley starch, tapioca starch, sweet potato starch, and potato starch.

4. The composite material according to claim 1, wherein the plasticizer is at least one of polyethylene glycol, polypropylene glycol, urea, glycerin, sorbitol, citric acid, acetyl triethyl citrate, and triethyl citrate.

5. The composite material of claim 1, wherein the coupling agent is a silane coupling agent or a boronic acid-containing organic compound, wherein the silane coupling agent comprises at least one of an amine-based silane coupling agent, a carboxyl-based silane coupling agent, and an epoxy-based silane coupling agent; the organic compound containing boric acid comprises at least one of phenylboronic acid, 1, 4-phenylboronic acid, 4-vinylphenylboronic acid and tetraphenylboronic acid.

6. The composite material of claim 1, wherein the dispersant is at least one of calcium stearate, zinc stearate, stearic acid, oleic acid, ethylene bis stearamide, oleamide, and erucamide.

7. The composite material of claim 1, wherein the compatibilizer is a compound having at least 2 isocyanate functional groups in a molecular chemical structure and includes at least one of diphenylmethane diisocyanate, toluene diisocyanate, dicyclohexylmethane diisocyanate, methylcyclohexane diisocyanate, hexamethylene diisocyanate, and p-toluene diisocyanate.

8. The composite material according to claim 1, wherein the antioxidant is at least one of hindered amine antioxidants, hindered phenol antioxidants, phosphites, metal deactivators, benzophenones, and benzotriazoles.

9. The method for preparing a starch-filled PLA/PBAT fully biodegradable composite according to any of claims 1-8, comprising the steps of:

weighing the components dried in advance according to the weight ratio, putting all the components into a high-speed mixer at 50-80 ℃, mixing for 20-30min, then putting the mixture into a double-screw extruder, and extruding and granulating under the conditions that the temperature is controlled at 130-165 ℃ and the screw rotation speed is 200-500rpm to obtain the composite material.

10. An environmentally friendly film or container prepared from the starch-filled PLA/PBAT fully biodegradable composite material of any one of claims 1-8.

Technical Field

The invention belongs to the field of high polymer materials, and particularly relates to a starch-filled PLA/PBAT full-biodegradable composite material and a preparation method thereof.

Background

At present, the scale of the production development and the demand of high polymer materials is rapidly increased, the consumption field is continuously expanded, plastics gradually replace various materials, and the plastic material plays an important role in all aspects of our lives, and the trend that steel is replaced by plastics and wood is replaced by plastics is more important. Therefore, the development and manufacture of environment-friendly completely biodegradable polymer materials have great economic and environmental value in global warming and petroleum resource reserve reduction today.

Polylactic acid (PLA) is a high molecular material formed by carrying out condensation polymerization or lactic acid dimer ring-opening polymerization on a lactic acid monomer formed by fermenting a biomass raw material by microorganisms, has good biodegradability, biocompatibility and antibacterial and anti-mildew properties, and can be conveniently processed and molded due to high tensile strength and compression modulus and good transparency. However, PLA is also very limited in its use, particularly in the packaging field, due to its hardness and brittleness, poor impact resistance, and poor hydrophilicity. Therefore, the modification of PLA has been a focus of research, especially in toughening modification.

Poly (butylene adipate terephthalate) (PBAT) is a biodegradable high polymer material with good toughness, and is thermoplastic plastic with PLA. In view of the complementarity of the properties between PLA and PBAT, the PLA/PBAT polymer alloy prepared by selecting the two materials to be melt blended not only can balance the rigidity and toughness of the materials, but also does not lose the biodegradability.

The high price of PLA and PBAT is one of the biggest reasons affecting their use as general purpose plastics. The filling modification is carried out on the modified epoxy resin, so that the cost can be reduced, and the aim of enhancing and toughening can be achieved to a certain extent. The PLA/PBAT filling agent can be divided into an inorganic filling agent and an organic filling agent according to the properties, wherein the completely renewable starch has low price and large storage capacity, and can effectively reduce the production cost and promote the biodegradation when being used as the PLA/PBAT alloy filling agent, so the PLA/PBAT full-biodegradable material filled with the starch is concerned and has been widely researched.

Disclosure of Invention

The invention provides a starch filled PLA/PBAT full biodegradable composite material and a preparation method thereof, the composite material not only solves the technical defects of poor toughness and brittle and easy breaking of polylactic acid, but also solves the technical problems of difficult processing of starch and poor compatibility with resin, and the obtained product has the characteristic of complete biodegradation.

In order to achieve the aim, the invention provides a starch filled PLA/PBAT full biodegradable composite material, which comprises the following components in parts by weight:

5-90 parts of polylactic acid (PLA), 10-90 parts of poly adipic acid/butylene terephthalate (PBAT), 10-50 parts of starch, 2-15 parts of plasticizer, 0.1-5 parts of coupling agent, 0.1-0.5 part of dispersant, 0.1-1 part of compatibilizer and 0.1-0.5 part of antioxidant.

The above technical solution provides the ranges of the weight parts of the components, it is understood that those skilled in the art can select the above ranges according to actual needs, for example, the weight parts of PLA can be 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85 parts or any value in the above ranges, the weight parts of PBAT can be 20, 30, 40, 50, 60, 70, 80 parts or any value in the above ranges, the weight parts of starch can be 15, 20, 25, 30, 35, 40, 45 parts or any value in the above ranges, the weight parts of plasticizer can be 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 parts or any value in the above ranges, the weight parts of coupling agent can be 0.5, 1, 2, 3, 4 parts or any value in the above ranges, and the weight parts of dispersant can be 0.2, 0.3, 0.4 parts or any value within the above range, 0.2, 0.3, 0.5, 0.6, 0.8 parts by weight of compatibilizer, and 0.2, 0.3, 0.4 parts by weight of antioxidant.

Preferably, the polylactic acid is at least one of dextrorotatory polylactic acid, levorotatory polylactic acid, racemic polylactic acid and a mixture thereof. Preferably, the starch is at least one of native starch, acetate starch and acetyl starch, wherein the native starch comprises at least one of corn starch, wheat starch, barley starch, tapioca starch, sweet potato starch and potato starch. In the above technical solutions, the selection of polylactic acid and starch is selected by those skilled in the art according to the actual situation, and is not limited to the range listed above, and besides, the poly (butylene adipate/terephthalate) is a commercially available general-purpose PBAT.

Preferably, the plasticizer is at least one of polyethylene glycol, polypropylene glycol, urea, glycerin, sorbitol, citric acid, acetyl triethyl citrate, and triethyl citrate. The plasticizer selected in the technical scheme can reduce the processing temperature of the component raw materials during blending and extrusion, improve the fluidity of the starch, reduce the problem that the starch becomes pasty and yellow in the processing process and simultaneously ensure the production yield.

Preferably, the coupling agent is a silane coupling agent or a boric acid-containing organic compound, wherein the silane coupling agent comprises at least one of an amino silane coupling agent, a carboxyl silane coupling agent and an epoxy silane coupling agent, the boric acid-containing organic compound comprises at least one of phenylboronic acid, 1, 4-phenylboronic acid, 4-vinylphenylboronic acid and tetraphenylboronic acid, the coupling agent selected in the technical scheme is considered from a structural unit of starch, the structural unit of starch is α -D-glucose, and the starch contains a large number of hydroxyl functional groups, and the siloxane functional groups of the silane coupling agent can react with polyhydroxy functional groups on the starch, so that the bonding force between the starch and the resin can be improved, in addition, the hydroxyl groups on the starch structural unit α -D-glucose are cis-diol structures, and the boric acid functional groups in the boric acid-containing compound can also react with the cis diol in the starch to generate a stable borate five-membered ring structure, so that the bonding force between the starch and the resin can also be improved.

Preferably, the compatibilizer is a compound having at least 2 isocyanate functional groups in a molecular chemical structure, and includes at least one of diphenylmethane diisocyanate, toluene diisocyanate, dicyclohexylmethane diisocyanate, methylcyclohexane diisocyanate, hexamethylene diisocyanate, and p-toluene diisocyanate. The compatibilizer selected in the technical scheme is an isocyanate compound containing multiple functionality, isocyanate functional groups react with terminal hydroxyl groups and terminal carboxyl groups of PLA, PBAT and hydroxyl groups of starch to generate a PLA-PBAT-starch ternary block copolymer, and the block copolymer can play a role of a surfactant, reduce the interfacial tension among the PLA, the PBAT and the starch, reduce the size of a disperse phase and improve the interfacial compatibility, thereby improving the comprehensive performance of the material.

Preferably, the dispersant is at least one of calcium stearate, zinc stearate, stearic acid, oleic acid, ethylene bis-stearic acid amide, oleic acid amide and erucic acid amide. Preferably, the antioxidant is at least one of hindered amine antioxidants, hindered phenol antioxidants, phosphites, metal deactivators, benzophenones, and benzotriazoles. In the above technical solutions, the selection of the dispersant and the antioxidant is selectable by those skilled in the art according to actual situations, and is not limited to the ranges listed above.

The invention provides a preparation method of a starch filled PLA/PBAT full biodegradable composite material according to any one of the technical schemes, which comprises the following steps:

weighing the components dried in advance according to the weight ratio, putting all the components into a high-speed mixer at 50-80 ℃, mixing for 20-30min, then putting the mixture into a double-screw extruder, and extruding and granulating under the conditions that the temperature is controlled at 130-165 ℃ and the screw rotation speed is 200-500rpm to obtain the composite material. The conditions for pre-drying in this embodiment may be set to drying at 60-100 deg.C for 3-5 hours, preferably at 80 deg.C for 4 hours, and can be adjusted by those skilled in the art according to actual conditions.

In the above technical solutions, a person skilled in the art can select parameters within the above range according to actual requirements, for example, the temperature during high-speed mixing can be 55, 60, 65, 70, 75 ℃ or any value within the above range, the time can be 25min, and the rotation speed can be 250, 300, 350, 400, 450rpm or any value within the above range.

The invention provides an environment-friendly film or container prepared from the starch-filled PLA/PBAT full-biodegradable composite material according to any technical scheme. Such as packaging films, handbag, synthetic paper films, disposable tableware, disposable daily necessities, etc.,

compared with the prior art, the invention has the advantages and positive effects that:

the preparation method of the starch filled PLA/PBAT full biodegradable composite material provided by the invention is simple to operate and short in production period, and solves the technical problems that starch is difficult to process and poor in compatibility with resin, so that the obtained product has the full biodegradable characteristic. The composite material provided by the invention can be widely applied to films or containers, such as packaging films, hand bags, films for synthetic paper, disposable tableware, disposable daily necessities and the like, and the obtained product can ensure the performance of the material, can reduce white pollution and meets the requirements of environmental protection.

Detailed Description

In order to more clearly and fully describe the starch-filled PLA/PBAT fully biodegradable composite material and the preparation method thereof provided in the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.