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以三元乙丙橡胶(EPDM)与共单体(M)甲基丙烯酸甲酯(MMA)、苯乙烯(St)和丙烯腈(AN)为原料,以悬浮接枝共聚合法合成了接枝共聚物EPDM-g-MAS,用其与SAN树脂共混制备了耐老化黄变性能优异的高抗冲塑料AEMS。研究了EPDM/M悬浮接枝共聚合的反应条件对单体转化率(CR)、接枝率(GR)、接枝效率(GE)以及AEMS冲击性能的影响。结果发现,EPDM/M悬浮接枝体系具有较高的CR、GR和GE,在适宜的聚合条件下,CR、GR和GE分别最高可达95.7%、75.3%和94.3%。接枝产物EPDM-g-MAS对SAN树脂具有显著的增韧作用。当EPDM/AEMS质量百分率为15%,AEMS的悬臂梁缺口冲击强度高达29.5kJ/m2。SEM分析表明,当EPDM含量低时,AEMS的增韧机理为裂纹支化及终止机理,当EPDM含量高时为裂纹终止与轻度剪切屈服机理。TG和热氧老化试验分析表明,AEMS比AES有更好的热稳定性和耐热氧老化黄变性能。
The graft copolymers were prepared by suspension graft copolymerization with EPDM and M (MMA), styrene (St) and acrylonitrile (AN) as raw materials. EPDM-g-MAS, with its SAN resin blends prepared anti-aging yellowing performance of high impact plastic AEMS. The effects of reaction conditions on the graft copolymerization of EPDM / M on the monomer conversion rate (CR), grafting rate (GR), grafting efficiency (GE) and impact performance of AEMS were investigated. The results showed that EPDM / M suspension grafting system has high CR, GR and GE, and under the suitable polymerization conditions, CR, GR and GE can reach up to 95.7%, 75.3% and 94.3% respectively. Grafting product EPDM-g-MAS has significant toughening effect on SAN resin. When the mass percentage of EPDM / AEMS is 15%, the Izod notched impact strength of AEMS is as high as 29.5kJ / m2. SEM analysis shows that when the content of EPDM is low, the toughening mechanism of AEMS is crack branching and termination mechanism. When the content of EPDM is high, the mechanism of crack termination and light shear yielding is the mechanism. TG and thermo-oxidative aging tests show that AEMS has better thermal stability and thermal yellowing resistance than AES.