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以高无机含量SiO2/聚甲基丙烯酸甲酯(PMMA)接枝复合材料为预分散母料,与PMMA树脂进行熔融共混,制得低无机含量的SiO2/PMMA复合材料.通过切片透射电镜(TEM)观察熔融共混过程中预分散母料内堆积SiO2粒子分散状态的演化.发现预分散母料接枝状态对其影响最为显著,不经接枝修饰的SiO2粒子经熔融共混后,不可避免地会在熔体中产生大量亚微米级的立体团聚体;复杂接枝预分散母料内构成以SiO2粒子为交联点的立体交联结构,其中的堆积SiO2粒子不能在剪切场中得到有效解离和释放;只有在使用简单接枝预分散母料时,基体高分子链才能不断地渗透扩散进入预分散母料内,而预分散母料可被不断地溶胀和撕裂,因而其中的堆积SiO2才可不断地向基体相迁移和扩散,并最终在整个复合材料内实现初级粒子形式的高度均匀稳定分散.
The SiO2 / PMMA grafted composites with high inorganic content as the pre-dispersed masterbatch were melt-blended with PMMA resin to prepare SiO2 / PMMA composites with low inorganic content. TEM) was used to observe the evolution of dispersed SiO 2 particles in the pre-dispersed masterbatch during the melt blending process.The results showed that the grafting state of the pre-dispersed masterbatch had the most significant effect on the dispersed particles, To avoid a large number of submicron-sized three-dimensional aggregates in the melt; complex graft pre-dispersed masterbatch to form a three-dimensional cross-linked structure with SiO2 particles as the crosslinking point, wherein the accumulated SiO2 particles can not be in the shear field Effective dissociation and release; only when using a simple grafting pre-dispersed masterbatch, the matrix polymer chain can continue to penetrate and diffuse into the predispersed masterbatch, and the predispersed masterbatch can be continuously swollen and torn, thus In which the accumulated SiO2 can continue to migrate and diffuse to the matrix phase and eventually achieve a highly uniform and stable dispersion of primary particles throughout the composite.