Wang Xianzeng, Mi Jianguo, Wang Jie, Zhou Hongfu, Wang Xiangdong
School of Materials Science and Mechanical Engineering, Beijing Technology and Business University Beijing 100048 People's Republic of China
Beijing Key Laboratory of Quality Evaluation Technology for Hygiene and Safety of Plastics Beijing 100048 People's Republic of China.
RSC Adv. 2018 Oct 8;8(60):34418-34427. doi: 10.1039/c8ra07510g. eCollection 2018 Oct 4.
Poly(ethylene octene) grafted with glycidyl methacrylate (POE--GMA) was employed to improve the rheological and thermal properties, toughness, and foaming behaviors of poly(lactic acid) (PLA) through a chain extension effect. The dynamic rheological properties of PLA were improved significantly with increasing content of POE--GMA, due to the chain extension reaction between PLA and POE--GMA. As the content of POE--GMA increased, the cold crystallization temperature of PLA decreased by more than 10 °C and the crystallinity of PLA increased slightly from 1.2% to 4.7%, respectively. The impact strength of PLA with a POE--GMA content of 10 wt% increased by more than 4 times, compared with that of pure PLA. A sea-island structure could be observed in the PLA/POE--GMA blends and the distribution of POE--GMA was uniform. PLA foams with various POE--GMA contents were prepared in a stainless-steel autoclave using supercritical CO as a physical blowing agent. The cellular morphology of PLA foam was obviously improved when the concentration of POE--GMA increased from 5 wt% to 10 wt%.
通过链增长效应，采用甲基丙烯酸缩水甘油酯接枝的聚（乙烯 - 辛烯）（POE - GMA）来改善聚乳酸（PLA）的流变学和热性能、韧性及发泡行为。由于PLA与POE - GMA之间的链增长反应，随着POE - GMA含量的增加，PLA的动态流变性能显著改善。随着POE - GMA含量增加，PLA的冷结晶温度分别降低超过10℃，结晶度从1.2％略微增加到4.7％。与纯PLA相比，POE - GMA含量为10 wt％的PLA的冲击强度提高了4倍以上。在PLA/POE - GMA共混物中可观察到海岛结构，且POE - GMA分布均匀。以超临界CO作为物理发泡剂，在不锈钢高压釜中制备了具有不同POE - GMA含量的PLA泡沫。当POE - GMA的浓度从5 wt％增加到10 wt％时，PLA泡沫的泡孔形态明显改善。
