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用硅烷偶联剂3-(甲基丙烯酰氧)丙基三甲氧基硅烷(MPS)对分散于乙醇中的纳米SiO2进行偶联改性,再通过介质置换和原位本体聚合制得SiO2/甲基丙烯酸甲酯(MMA)单体分散液和SiO2/PMMA复合材料.红外光谱分析(FTIR)和热重分析(TG)结合洗提实验考察了SiO2表面MPS的偶联率和偶联效率,透射电镜(TEM)和动态激光粒度分析(DLS)考察了SiO2在乙醇、单体和聚合物基体中的分散状态,在此基础上推测MPS在SiO2颗粒表面的表观偶联密度和偶联形式,分析偶联程度对单体和聚合物基体中不同粒径SiO2分散性的影响.发现MPS主要以低聚物形式偶联于SiO2颗粒表面;SiO2分散性主要与其表面MPS的表观偶联密度相关,当偶联密度在1.3～5.6μmol.(m2.SiO2)-1范围内时,MPS偶联完全,SiO2表面改性充分,相应的SiO2颗粒可在单体和聚合物基体内达到初级粒子形式的高度均匀稳定分散,且这种高分散性在实验范围内基本不受SiO2含量的影响.
The silane coupling agent 3- (methacryloyloxy) propyl trimethoxysilane (MPS) was used to modify the nano-SiO2 dispersed in ethanol, and then the SiO2 / Methyl methacrylate (MMA) monomer dispersion and SiO2 / PMMA composites.FTIR and TG combined with elution experiments were used to investigate the coupling efficiency and coupling efficiency of MPS on SiO2 surface, Transmission electron microscopy (TEM) and dynamic laser particle size analysis (DLS) were used to investigate the dispersion of SiO2 in ethanol, monomer and polymer matrix. Based on this, the apparent coupling density of MPS on the surface of SiO2 particles and the coupling form , The influence of the degree of coupling on the dispersibility of different particle size SiO 2 in the monomer and polymer matrix was analyzed.The MPS was found to be mainly oligomer coupled to the surface of the SiO 2 particle.The dispersion of SiO 2 was mainly related to the apparent coupling density , When the coupling density is in the range of 1.3 ~ 5.6μmol. (M2.SiO2) -1, the MPS coupling is complete and the surface modification of SiO2 is sufficient. The corresponding SiO2 particles can reach the primary particles in the monomer and polymer matrix The form of highly uniform and stable dispersion, and this high dispersion within the experimental range Under the influence of SiO2 content.