Influence of core-shell rubber particles synthesized with different initiation systems on the impact toughness of modified polystyrene
Influence of core-shell rubber particles synthesized with different initiation systems on the impact toughness of modified polystyrene
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DOI：
10.1002/app.25030
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发表时间：
2007-01-15
影响因子：
3
通讯作者：
Zhang, Huixuan
中科院分区：
文献类型：
--
作者：
Gao, Guanghui;Zhou, Chao;Zhang, Huixuan
采用乳液接枝聚合法，在不同引发体系下合成了核壳型聚丁二烯-接枝-苯乙烯（PB-g-PS）橡胶粒子。这些引发体系包括氧化还原引发剂和油溶性引发剂1，2-偶氮二异丁腈（AIBN）。然后将PB-g-PS抗冲改性剂与聚苯乙烯（PS）共混制备PS/PB-g-PS共混物。在两种样品拉伸屈服强度相同的情况下，悬臂梁测试表明，PS/PB-g-PS（AIBN）的缺口冲击强度为237.8 J/m，几乎是PS/PB-g-PS（氧化还原）共混物37.2 J/m的7倍。透射电镜照片显示，在氧化还原引发剂作用下，PB橡胶粒子的核内存在PS微相区，即“内接枝”现象。“这种嫁接方式对增韧效果不佳。而以AIBN为引发剂时，在PB粒子核内形成了大规模的PS亚包体，这种微结构增加了橡胶相的有效体积分数，从而提高了改性聚苯乙烯的韧性。动态力学分析（DMA）结果表明，PS/PB-g-PS（AIBN）橡胶相的玻璃化转变温度（Tg）低于PS/PB-g-PS（氧化还原）橡胶相的Tg。结果表明，PB-g-PS（AIBN）对改性聚苯乙烯的增韧效果优于PB-g-PS（redox），符合Kerner近似方程。(c)2006 Wiley Periodicals，Inc.
Core-shell poly(butadiene-graft-styrene) (PB-g-PS) rubber particles were synthesized with different initiation systems by emulsion grafting polymerization. These initiation systems included the redox initiators and an oil-soluble initiator, 1,2-azobisisobutyronitrile (AIBN). Then the PB-g-PS impact modifiers were blended with polystyrene (PS) to prepare the PS/PB-g-PS blends. In the condition of the same tensile yield strength on both samples, the Izod test showed that the notched impact strength of PS/PB-g-PS(AIBN) was 237.8 J/m, almost 7 times than that of the PS/PB-g-PS(redox) blend, 37.2 J/m. From transmission electron microscope (TEM) photographs, using the redox initiators, some microphase PS zones existed in the core of PB rubber particles, which is called "internal-grafting." This grafting way was inefficient on toughening. However, using AIBN as initiator, a great scale of PS subinclusion was seen within the PB particle core, and this microstructure increased the effective volume fraction of the rubber phase with a result of improving the toughness of modified polystyrene. The dynamic mechanical analysis (DMA) on both samples showed that the glass transition temperature (T,,) of rubber phase of PS/PB-g-PS(AIBN) was lower than that of PS/PB-g-PS(redox). As a result, the PB-g-PS(AIBN) had better toughening efficiency on modified polystyrene than the PB-g-PS(redox), which accorded with the Kerner approximate equation. (c) 2006 Wiley Periodicals, Inc.