摘要
通过双螺杆挤出机和吹膜机组制备不同比例的聚乳酸/聚对苯二甲酸-己二酸-丁二酯(PLA/PBAT)共混物薄膜,测量共混物的热性能、力学性能.并观察其相形貌.计算共混物在堆肥条件下的生物降解率,研究共混物降解前后的结构、热力学行为和元素的变化。结果表明,PLA与PBAT是不相容体系,加入PBAT后PLA的韧性得到改善;PLA的生物降解率高于PLAT,共混物的生物降解率随着PBAT含量的增加而降低,且在降解初期,PLA的降解产物会促进PBAT的水解;PLA,PBAT及其共混物在堆肥降解前期只是大分子链水解为小分子链的过程,不发生分子链的结构变化;PLA及PBAT的降解会先发生在无定形区,共混物中PLA在无定形区的降解速度受到PBAT的影响而变慢,且共混物中PLA、PLAT的降解行为发生变化,无定形区与结晶区的降解同时发生;共混物在堆肥试验初期的降解以水解为主。
In this study, blended film of poly （lactic acid） （PLA）/POly （butylene adipate-co terephthalate） （PBAT） was prepared by a twin-screw extruder and a single screw extruder. The thermal, mechanical properties and microstructure had been investigate＆ The biodegradation rate of the blends under congesting condition was measured, and the structure, element content, and thermomechanieal behavior before and after degradation was characterized. It indicated that PLA/PBAT blend was an immiscible system, and the addition of PBAT improved the flexibility of PLA. It also found that, the biodegradation rate of neat PLA was greater than that of neat PBAT, and the biodegradation rate of PLA/PBAT blends was decreased with increasing PBAT content. Furthermore, the degradation products may accelerate the hydrolysis of PBAT at the beginning of degradation. At the earlier stage of degradation under composting condition, the long polymer chins of PLA, PBAT and their blends hydrolyzed to short chains without chemical structure change of the monomers. The degradation of neat PLA and PBAT initially occurred at amorphous phase, however the degradation of PLA/PBAT blends occurred at both amorphous and crystalline phases simultaneously. Moreover, the degradation of PLA chains in amorphous phase in blends was decreased affected by the addition of PBAT. The degradation of PLA/PBAT blends was mainly started with a hydrolysis.
出处
《中国塑料》
CAS
CSCD
北大核心
2016年第8期79-86,共8页
China Plastics
基金
国家自然科学基金面上项目(51473006)
国家质枪总局公益性行业研究项日(201310256)
