环氧官能化POE增韧PET的研究

Study on toughening of PET by epoxy-functionalized POE

采用熔融接枝法,在乙烯-辛烯共聚物(POE)上接枝了不同含量的甲基丙烯酸缩水甘油酯(GMA),制备了POE接枝物POE-g-GMA,并用于增韧聚对苯二甲酸乙二醇酯(PET)。考察了不同GMA接枝量的POE对PET结构与性能的影响。结果表明:在弹性体含量相同时,随着GMA接枝量的增加,GMA中的环氧官能团与PET的端羟基和端羧基反应性加强,从而使PET共混物的加工黏度增加,平衡扭矩升高;PET中POE分散相尺寸显著减小,两相间的玻璃化转变温度差值逐渐缩小,PET与POE间的相容性有所提高;力学性能结果表明随着弹性体含量的增加,PET与纯POE、GMA接枝量为1%的POE形成共混物的缺口冲击强度和纯PET的差别不大,说明纯POE与GMA接枝量为1%的POE不能实现对PET的有效增韧,而GMA接枝量为2%和3%时,随着弹性体含量逐渐增加,PET共混物冲击强度逐渐增加,均超过600J/m,能够有效地增韧PET。但两者的脆韧转变点不同,当接枝量为2%,弹性体含量在25%~30%发生脆韧转变,当接枝量达到3%时,脆韧转变提前,发生在弹性体含量15%~20%。说明在考察范围内,GMA接枝量2%和3%的POE能够有效地增韧PET,且当GMA接枝量为3%时,脆韧转变提前,增韧效果最佳。

Ethylene-octene copolymer(POE) was grafted with different content glycidyl methacrylate(GMA) by melt grafting processes to prepare POE-g-GMA.POE-g-GMA was used to toughen poly(ethylene terephthalate)(PET).The effect of POE with different grafting amount on the structure and mechanical properties of PET blends were investigated.The results showed that the epoxy functional groups in GMA with the terminal hydroxyl or carboxyl groups of PET was activated with the increase of the grafting amount of GMA.The processing viscosity of the PET blends and the equilibrium torque increased as the increase of the grafting amount of GMA.The size of the dispersed phase of POE in PET was significantly reduced, the glass transition temperature between the two phases was gradually decreased, and improved the compatibility between PET and POE.The mechanical properties results showed that the notched impact strength of PET/POE and PET/POE-GMA1 was not much different from that of pure PET with the increase of the elastomer content.The results indicated that PET was not toughened by the pure POE and POE-g-GMA1.While the grafting amount of GMA was 2% and 3%,the impact strength of the PET blends gradually increased as the content of elastomer gradually increased, both exceeding 600 J/m.PET could be toughened effectively.But the brittle-ductile transition point of them was different.When the grafting amount was 2%,the elastomer content was 25%~30%,the brittle-ductile transition occurred.When the grafting amount reached 3%,the brittle-ductile transition was advanced and occurred in the 15%~20% of elastomer.It showed that within the scope of investigation, PET could be toughened effectively by POE-g-GMA2 and POE-g-GMA3.When the grafted amount of GMA was 3%,the brittle-ductile transition was advanced and PET was effectively toughened.