本体原位法制备高抗冲聚苯乙烯Ⅰ.引发剂的影响

摘要

以稀土催化体系磷酸酯钕盐/氢化二异丁基铝/一氯二乙基铝在苯乙烯中选择性地使丁二烯聚合,并且以自由基引发剂过氧化苯甲酰、1,1-二(叔丁基过氧基)环己烷、3,6,9-三甲基-3,6,9-三乙基-1,4,7-三过氧烷(TETMTPA)或2,2-二(4,4-二叔丁基过氧环己基)丙烷引发聚丁二烯和苯乙烯聚合制备高抗冲聚苯乙烯(HIPS).在相同的官能团浓度下,TETMTPA引发的聚合反应速率最快,制备的HIPS冲击强度最高.随着TETMTPA用量从0.01 phr提高至0.05 phr,聚合反应速率增加,HIPS的悬臂梁缺口冲击强度从120.6 J/m降至72.4 J/m.%Butadiene was selectively polymerized with Nd(P507)3/AIH(I--Bu)2/AIEt2Cl catalyst in styrene so as to prepare butadiene prepolymer solution. Then high impact polystyrene(HIPS) was prepared from the prepolymer and styrene in the presence of benzoyl peroxide, l,l-di(tert-butylperoxy)cyclohexane, 3,6,9-triethyl-3,6,9-trimethyl-l,4,7-triperoxonane (TETMTPA) or 2,2-bis(4,4-di-(tert-butyl-peroxy- cyclohexyl)propane) as radical initiator. TETMTPA gave the highest polymerization rate among these radical initiators with equivalent functionality; the HIPS prepared with TETMTPA had the highest impact strength compared with its counterparts. The polymerization rate increased with augmenting the initiator concentration from 0.01 phr to 0.05 phr, whereas the notched Izod impact strength of the HIPS decreased from 120.6 J/m to 72.4 J/m.