【摘要】 为改善二氧化硅(SiO2)纳米粒子与聚合物基体间的亲和性,使SiO2表面功能化,将硅烷偶联剂KH-570引入C=C基团,采用乳液聚合方法在纳米SiO2粒子表面接枝苯乙烯(St)单体,实现了纳米二氧化硅表面的聚苯乙烯(PS)高分子包覆改性,制备了具有核/壳结构的SiO2-PS复合纳米粒子,产物的单体转化率和接枝效率在80%以上.研究了二氧化硅含量和偶联剂用量对聚合反应的单体转化率和接枝效率的影响,探讨了偶联剂的作用机理,利用FT-IR、TEM、TG对SiO2-PS复合粒子的表面结构进行了表征.结果表明,复合粒子具有明显的核壳结构,壳层厚度在20nm左右,乳液聚合过程可有效使二氧化硅的团聚体剥离呈纳米级颗粒.更多还原

【Abstract】 To improve the compatibility between nano-SiO2 particles and polymeric matrix,and make the surface of nano-SiO2 functionalized,nano-SiO2 particles were treated with silane coupling agent(KH-570) and groups of C = C were introduced onto the surface of nano-SiO2 particles successfully.Polystyrene was further grafted on the treated nano-SiO2 particles surfaces via emulsion polymerization,and composite particles of SiO2-PSt,with both monomer conversion and grafting efficiency higher than 80%,were obtained.Influences of the ratio of SiO2 and KH-570 on monomer conversion and binding efficiency in the polymerization reaction were investigated.The mechanism of silane coupling agent(KH-570) was also discussed.The surface structures,morphologies and the distribution of nano-SiO2 particles in polystyrene were characterized with FT-IR,TEM and TG.Results indicated that the surface grafting treated by nano-SiO2 composite particles had an obvious core-shell structure and the thickness of polymer shells was around 20 nm.The aggregated nano-SiO2 particles were gradually dispersed during the emulsion polymerization.更多还原