填充油对聚苯乙烯-b-聚〔乙烯-(乙烯-丙烯)〕-b-聚苯乙烯结构与性能的影响

研究了油品的种类及环烷烃油用量对聚苯乙烯-b-聚〔乙烯-(乙烯-丙烯)〕-b-聚苯乙烯(SEEPS)加工性能、物理机械性能、微观结构及玻璃化转变温度的影响。结果表明,环烷烃油和石蜡油均能明显改善SEEPS的加工流动性;环烷烃油填充SEEPS的物理机械性能优于石蜡油填充者;新疆和天津产环烷烃油填充SEEPS的物理机械性能相近,但天津产环烷烃油挥发分含量略高。填充100质量份Nyflex 222 B环烷烃油(NNO)的SEEPS具有较好的塑化成型性和物理机械性能。在此基础上再增加填充油量,SEEPS的定伸应力、拉伸强度和撕裂强度降低,扯断伸长率增大,但永久变形变化不大。NNO可均匀地渗入SEEPS弹性段和塑性段微区,其对SEEPS弹性微区的玻璃化转变温度基本没有影响,但会降低SEEPS塑性微区的玻璃化转变温度。

Effects of extender oil on the structure and properties of styrene-[ethylene-(ethylene-propylene)]-styrene block copolymer

The effects of four types of extender oils and the amounts of naphthenic oil on the processability,mechanical properties,micro-phase structure and glass transition temperature(T_g) of styrene-[ethylene-(ethylene-propylene)]-styrene block copolymer(SEEPS) were investigated.It was found that all the four extender oils could improve the fluidity of SEEPS greatly while the naphthenic ones were better in improving the mechanical properties of SEEPS.The properties of SEEPS blended with the naphthenic oils made by Xijiang and Tianjin respectively were nearly the same,but Nyflex 222 B naphthenic oil(NNO) had a lower content of volatile constituent.When filled with 100 phr NNO,SEEPS obtained good processability and mechanical properties.As the amount increased,the modulus,tensile strength and tear strength of the blends gradually decreased but elongation at break increased and permanent set hardly changed.NNO was capable of infiltrating(evenly) into both mid-block(EEP) block and polystyrene(PS) block.NNO had no effect on the glass transition temperature of EEP but it could obviously reduce the T_g of PS block.