N-苯基马来酰亚胺/苯乙烯/聚丁二烯本体聚合中的相转变(Ⅱ) 聚合条件对相转变和橡胶相结构的影响

进行了N -苯基马来酰亚胺 (PMI) /苯乙烯 (St)在聚丁二烯 (PB)存在下的半连续本体共聚合 ,研究了聚合的操作条件及配方对聚合过程中的相转变及转相后橡胶相结构的影响 .发现提高搅拌转速使相转变提前 ,升高聚合温度、增加引发剂用量、提高PMI及橡胶含量都使转相期延迟 .降低搅拌转速、提高聚合温度和橡胶含量易使橡胶相粒径增大 ,表观接枝率上升 .在一定范围内提高过氧化二苯甲酰 (BPO)浓度也将使接枝率上升 ,但PMI的引入不利于单体在橡胶上的接枝 .

PHASE INVERSION DURING BULK COPOLYMERIZATION OF N -PHENYLMALEIMIDE/STYRENE IN PRESENCE OF POLYBUTADIENE (Ⅱ) EFFECTS OF OPERATION CONDITIONS AND RECIPES ON OCCURRENCE OF PHASE INVERSION AND STRUCTURE OF RUBBER PHASE

To prepare the high impact polystyrene with good heat resistance, semi-continuous bulk copolymerization of N -phenylmaleimide (PMI) and styrene in the presence of polybutadiene(PB) was carried out in a 2 L stirred tank reactor with a double helical impeller. The effects of polymerization conditions on phase inversion and micro - structure of rubber phase were investigated. It was found that the higher the polymerization temperature and concentrations of PB, initiator and PMI, the earlier the phase inversion occurred, but with raised agitation rate in a later phase inversion. The effects of polymerization technology on the structure of rubber phase, such as particle size, subcontainings in rubber particles, indicate that raising agitation rate,polymerization temperature and the concentration of PB cause higher grafting ratio and larger rubber particles. An increase in the concentration of initiator,BPO,is favorable to raising the grafting ratio. However, an introduction of PMI reduces the value.