Abstract: Polystyrene-g-polydimethylsiloxane copolymers were prepared by using the methacryloxypropyl-polysiloxane(PDMS-MA) macromonomer technique.The structures of graft copolymers were characterized by Fourier transform infrared(FTIR) spectroscopy.The influence of molecular mass of PDMS-MA on copolymerization activity was investigated.Thermal properties of the graft copolymer were also studied.The reactivity of PDMS-MA decreased with increasing molecular mass. Meanwhile with increasing ratio of PDMS-MA to styrene, the copolymerization conversion of PDMS-MA decreased. The heat-resistance of PSt-g-PDMS was improved comparing to PSt alone.The improvement was greater when the molecular mass of PDMS-MA and its contents were increased.

Key words: 大单体, 聚硅氧烷, 聚苯乙烯, 接枝共聚物

摘要： 以甲基丙烯酰氧丙基聚硅氧烷大单体(PDMS-MA)与苯乙烯共聚合,制备了聚苯乙烯-聚硅氧烷梳状接枝共聚物（PSt-g-PDMS），采用傅里叶变换红外光谱（FTIR）表征了接枝共聚物的组成，研究了聚硅氧烷大单体的相对分子质量对共聚合活性的影响，并对接枝共聚物的热性能进行了表征.结果表明，大单体PDMS-MA的共聚合活性随其相对分子质量的增大而减小，随投料比的增加，共聚合转化率下降.与纯聚苯乙烯相比，PSt-g-PDMS的热稳定性提高.而且，随着大单体PDMS-MA相对分子质量和它在共聚物中含量的增加，接枝共聚物的热稳定性增加.

关键词: 大单体, 聚硅氧烷, 聚苯乙烯, 接枝共聚物