环氧化EPDM对PBT/LLDPE共混体系的微观形态及力学性能的影响研究

Effect of Epoxidized EPDM on Morphologies and Mechanical Properties of PBT /LLDPE Blends

采用反应性熔融共混技术制备了聚对苯二甲酸丁二醇酯(PBT)/线型低密度聚乙烯(LLDPE)共混物,并采用环氧化三元乙丙橡胶(eEPDM)为增容剂改善PBT/LLDPE共混体系的相容性。使用红外光谱(FTIR)和扫描电子显微镜(SEM)等手段对共混物进行了分析和相形态观察,并测试了力学性能,研究了eEPDM对PBT/LLDPE共混体系形态结构和力学性能的影响。研究结果表明,熔融共混过程中eEPDM的环氧基团与PBT的端羧基发生化学反应,就地生成PBT-g-EPDM共聚物,该共聚物可对PBT/LLDPE共混物起到良好的增容作用。与PBT/LLDPE/EPDM共混体系相比,PBT/LLDPE/eEPDM共混物的相区尺寸更小,分布更窄,而且加入eEPDM在改善冲击强度方面比添加EPDM更有效。

Poly（butylene terephthalate） （PBT）/liner low density polyethylene （LLDPE） blends had been prepared by using reactive melting compounding technology.In order to improve the compatibility of PBT/LLDPE blend,epoxidized ethylene-propylene-diene monomer （eEPDM） rubber was used as a compatibilizer.The effects of eEPDM on the morphologies and mechanical properties of PBT/LLDPE blends were investigated.The PBT/LLDPE blends were investigated and the phase morphology was observed by means of Fourier transform infrared spectroscopy and scanning electron microscopy.The experimental results showed that the epoxy groups of eEPDM reacted with the terminal carboxylic acid group of PBT,thus leading to the formation of PBT-g-EPDM copolymer.The PBT-g-EPDM copolymer acted as a compatibilizer between PBT and LLDPE.Compared with PBT/LLDPE/EPDM blend,a more uniform and fine dispersed phase of PBT/LLDPE/eEPDM blends was observed.Moreover,the addition of eEPDM also improved the impact properties of PBT/LLDPE blends better than EPDM.