CN-117050482-B - Completely biodegradable film and preparation method thereof

Abstract

The invention relates to the technical field of materials, in particular to a polybutylene terephthalate/starch/carbon dioxide-based thermoplastic polyurethane completely biodegradable film and a preparation method thereof. The fully biodegradable film comprises 40-65 parts by weight of polybutylene terephthalate-adipate resin (PBAT), 15-30 parts by weight of modified starch (TPS), 9-40 parts by weight of carbon dioxide-based thermoplastic polyurethane (PPCU), 0.1-1 part by weight of an opening agent and 0.1-2 parts by weight of a lubricant. According to the invention, the polybutylene terephthalate-adipate resin is mixed with the modified starch, the carbon dioxide-based thermoplastic polyurethane and the rest of auxiliary agents, and the specific proportion is combined, so that the film prepared from the composition finally prepared has the advantages of high tensile strength and tearing strength, good elastic modulus, good elongation at break, good moisture resistance and water resistance, good barrier property, good degradation property and the like.

Inventors

• PAN HONGWEI
• WANG ZEPENG
• BIAN JUNJIA
• ZHANG HUILIANG
• WANG JIN
• JIN BAOCHANG
• YANG HUILI
• ZHANG RENHAO

Assignees

• 江苏碧升生物新材料有限公司
• 中国科学院长春应用化学研究所

Dates

Publication Date

20260512

Application Date

20230906

Claims (5)

1. 1. A fully biodegradable film is characterized by comprising 40-65 parts by weight of polybutylene terephthalate-adipate resin (PBAT), 15-30 parts by weight of modified starch (TPS), 9-40 parts by weight of carbon dioxide-based thermoplastic polyurethane (PPCU), 0.1-1 part by weight of an opening agent and 0.1-2 parts by weight of a lubricant; The modified starch is modified by a modifier and contains a plasticizer, wherein the modifier is any one of citric acid or maleic anhydride, and is mixed with any one of a titanate coupling agent, an aluminate coupling agent and a silane coupling agent; The opening agent is erucamide or oleamide; The lubricant is glyceryl monostearate; the modified starch is modified corn starch or tapioca starch, and the weight ratio of starch, plasticizer and modifier in the modified starch is 70-75:20-25:1-3; the weight ratio of any one of the citric acid or the maleic anhydride to any one of the titanate coupling agent, the aluminate coupling agent and the silane coupling agent is 1:1-1:0.2; The carbon dioxide-based thermoplastic polyurethane has a weight average molecular weight of 6X 10 4 g/mol to 5X 10 5 g/mol.
2. 2. The fully biodegradable film according to claim 1, wherein the fully biodegradable film comprises 45-60 parts by weight of polybutylene terephthalate-adipate resin, 17-22 parts by weight of modified starch, 20-30 parts by weight of carbon dioxide-based thermoplastic polyurethane, 0.2-0.5 part by weight of an opening agent and 0.5-1.2 parts by weight of a lubricant.
3. 3. A method for producing a completely biodegradable film according to any one of claims 1 to 2, comprising the steps of: 1) Mixing starch, plasticizer and modifier for modification treatment to obtain modified starch; 2) Mixing and extruding polybutylene terephthalate-adipate resin, modified starch, carbon dioxide-based thermoplastic polyurethane, an opening agent and a lubricant to obtain resin for film blowing; 3) And (3) carrying out film blowing on the film-blowing resin to obtain the polybutylene terephthalate-adipic acid/starch/carbon dioxide-based thermoplastic polyurethane completely biodegradable film.
4. 4. The method of claim 3, wherein in the step 2), the extrusion temperature is 80-185 ℃ and the screw rotation speed is 200-350 rpm.
5. 5. The method for preparing a completely biodegradable film according to claim 3, wherein in the step 3), the film blowing processing temperature is 150-185 ℃.

Description

Completely biodegradable film and preparation method thereof Technical Field The invention relates to the technical field of materials, in particular to a polybutylene terephthalate/starch/carbon dioxide-based thermoplastic polyurethane completely biodegradable film and a preparation method thereof. Background The environmental pollution caused by petroleum-based plastics is increasing, and the replacement of fully degradable plastics is urgently needed. Polybutylene terephthalate-adipate (PBAT) is a fully degradable plastic widely studied at home and abroad. But the thin film prepared by pure PBAT is softer, has smaller strength and higher cost, and is limited in a plurality of application fields. Thus, during application processing, PBAT is often blend modified with other materials to improve its application properties. The high cost of the raw materials of the PBAT is a main factor limiting the popularization and the use of the PBAT. Therefore, adding low cost fillers for blend modification during PBAT processing is an essential process, and Ningping et al reported studies on starch fill modified PBAT (Ning Ping, chen Mingyue, shotthe. Structure and performance studies on starch fill modified PBAT, chemical New Material, 2010,38 (7): 116-119). By adding the compatibilizer, the compatibility of the starch and the PBAT is obviously improved, and particularly when the content of the compatibilizer (EMH 4210) is 7 parts, the starch consumption is 10 percent, so that the better performance can be still maintained. The addition of the compatibilizer not only improves the dispersion effect of the starch, but also greatly improves the compatibility between the starch and the PBAT. However, the compatibilizer is not degraded, and the degradation performance of the material is affected. Qiao et al report the preparation of biodegradable TPS/PBAT composites (Qiaoping, xie Xinchun, tan Lei, to the preparation of synthetic resins and plastics for clearly biodegradable TPS/PBAT composites, 2009,26 (3): 13-16). Thermoplastic starch (TPS) is melt blended with PBAT and extruded to produce a fully biodegradable TPS/PBAT composite. After PBAT is added, the melt fluidity of the composite material is obviously improved, the tensile strength is firstly reduced from 6.36MPa to 3.31MPa and then increased to 12.98MPa, and the addition of PBAT inhibits the recrystallization of amylopectin molecules and reduces the water absorption rate of the composite material. The TPS/PBAT composite material prepared by the technology has low tensile strength, is not suitable for preparing shopping bag films, and has a narrow application range. Pan Hongwei, zhang Huiliang et al, journal of Korean Journal CHEMICAL ENGINEERING (2017,34 (5): 1294-1304.) reported that blending PBAT with carbon dioxide copolymer polypropylene carbonate (PPC) was extruded and blown into films, and studies showed that the addition of PPC increased the tensile strength and gas barrier properties of the PBAT/PPC film, and the literature reported the degradation of the film in soil, and the results showed that the PBAT/PPC film was particularly suitable for packaging bag applications. The PBAT/PPC film prepared by the technology has the advantage that the cost of PPC is high, namely about 20000 yuan/ton, and the application and popularization are limited by the cost. Zhang Huiliang et al discloses a ternary completely biodegradable film and a preparation method thereof (publication No. CN 113214615A), and a PBAT/PPC/TPS ternary blend blown film is prepared by adopting PBAT, polypropylene carbonate (PPC) and thermoplastic starch (TPS) to blend, modify, extrude and granulate, and then blowing by a film blowing machine, wherein the tensile strength of the film is lower than 20MPa, and the technology still has the defect of being difficult to bear larger load. Zhang Ye, zhang Huiliang et al, journal (plastics industry, 2018,46 (1): 99-103,146.) report the preparation of polylactic acid (PLA)/polybutylene succinate (PBS)/carbon dioxide based thermoplastic polyurethane (PPCU) films using melt blending and extrusion blown film processes. The PLA/PBS/PPCU film prepared by the technology has higher cost and is difficult to popularize and apply because of 30000 yuan/ton of PBS and 20000 yuan/ton of PLA. Yang Jia et al discloses a highly transparent fully degradable film and a preparation method thereof, and the patent (publication No. CN 113845761A) discloses a method for preparing the film, which comprises the steps of binary or multi-component blending, modifying, extruding and granulating by adopting PLA and a toughening agent PBAT, PBS, PPC, PPCU, and then carrying out film blowing processing by a film blowing machine to prepare a binary or multi-component blending blown film, wherein the PLA price of the film is about 20000 yuan/ton, the content is up to 80% -97%, the PBS price is about 30000 yuan/ton, the cost is higher, and the application and popularization are limited by