Preparation And Properties Of PBAT And Its Modified Molded Foam Materials

Poly(butanediol adipate-co-butanediol terephthalate)(PBAT)is a petroleum-based biodegradable plastic,which has the advantages of good toughness and soft quality.The foam material made of PBAT is an ideal substitute for vinyl acetate copolymer(EVA)foam material.However,the existing PBAT resin has a single hardness,which makes it difficult to prepare foaming materials with different degrees of hardness as EVA foaming materials.In addition,there are few reports on the preparation of PBAT foaming boards.In this paper,using the polymer supercritical molding foam device,supercritical CO2 fluid as foaming agent,through the molding foam technology to prepare green PBAT foaming material,systematically study the foaming behavior of PBAT and the evolution of the cellular structure,at the same time,By blending PBAT with other hard bioplastics such as polylactic acid(PLA)and polylbutylene succinate(PBS),biodegradable foaming materials with different degrees of softness and hardness were prepared by molding foam technology.The influence of phase morphology and process conditions on the foaming behavior of PBAT/PLA and PBAT/PBS was systematically studied,which laid a certain foundation for the subsequent industrial production of the enterprise.The main research contents and results are as follows:The PBAT biodegradable foaming material was prepared by using the polymer supercritical fluid molding foaming device and system,using supercritical CO2 fluid as foaming agent,and the foaming material with the highest expansion rate of 8.4 times and cell density of 2.8×108 cells/cm3 was prepared.The effects of saturation pressure and temperature on the expansion rate and morphology of foaming materials were systematically investigated,the effects of technological parameters on the hardness of foaming materials were studied,and the principle of influencing technological parameters was explained.By blending PBAT with PLA and PBS,a biodegradable polymer foam material with the same hardness as the mainstream EVA foam material in the market and improved foaming morphology was prepared.The effects of different process parameters on the hardness of biodegradable foam material were studied.The effects of PBAT/PLA and PBAT/PBS compatibility,PLA and PBAT content and foaming conditions on the expansion rate and foaming properties of biodegradable mixture were investigated.By comixing PLA in PBAT,the maximum hardness of foam material was increased by nearly40%.In addition,under the optimal foaming window,the hardness of PBAT/PBS foam material was close to that of PBAT/PLA foam material,and the expansion ratio of PBAT/PBS foam material was increased by about 11% compared with the latter.