【作者】 林宇； 刘朗萍； 吴国章；

【Author】 Yu Lin;Langping Liu;Guozhang Wu;Shanghai Key Laboratory of Advanced Polymeric Materials,School of Materials Science and Engineering,East China University of Science and Technology;

【机构】 华东理工大学材料科学与工程学院上海市先进聚合物重点实验室；

【摘要】 采用细乳液聚合制备了不同接枝链长度和密度的聚苯乙烯接枝二氧化硅纳米复合粒子（SiO₂-PS）,用以填充PS和聚甲基丙烯酸甲酯（PMMA）,考察了接枝链聚合度（N）、接枝链密度（σ）、基体链聚合度（P）以及接枝链与基体链相容性对纳米粒子空间分布的影响规律。采用宽频介电谱系统研究了复合体系链段动力学,揭示了纳米粒子周围接枝链和基体链的界面层弛豫行为。结果显示,当σ·N^0.5≥（N/P）²时,接枝链与基体链间相互排斥,界面层松弛远快于基体链松弛。此外,在聚合物玻璃化转变温度（T_g）附近,由于受慢的基体链松弛影响,界面层松弛时间随温度升高反而增大。更多还原

【Abstract】 Polystyrene-grafted silica nanoparticles（SiO₂-PS） with different grafted chain length and grafting density were prepared via miniemulsion polymerization.The spatial distribution of grafted nanoparticles（NPs） in PS and poly（methyl methacrylate）（PMMA） matrices were investigated by morphology observation.More interestingly,we probed the enhanced mobility of interfacial layer（a’-relaxation） in grafted NP filled composites.In addition,it was unexpected that the a’-relaxation time increased with increasing temperature in the vicinity of glass transition temperature（T_g） of polymer matrix.Such an anomalous temperature dependence behavior can be attributed to the influence exerted by the slower α-relaxation dynamics.更多还原