丙烯酸酯类聚合物乳液法修饰纳米SiO_2粒子研究

Surface Modification of SiO2 Composite Nanoparticles by Emulsion Polymerization

采用带有羧基活性官能团的丙烯酸酯类聚合物乳液对纳米SiO2进行表面修饰。并用透射电镜、红外、热失重、接触角、粒径分析对处理效果进行了表征。结果表明：所制备的含羧基基团的共聚物乳胶粒子在机械搅拌作用下，与粒径为15—20nm左右的无机SiO2纳米粒子的作用过程中，实现了对SiO2表面修饰和分散的效果。当复合温度（65℃）高于改性用聚合物的Tg（45℃）时，柔软的聚合物乳胶粒子变形、黏附在SiO2纳米粒子周围，并通过羧基的化学吸附作用最终实现对SiO2粒子的包覆；当复合温度（25℃）低于改性用聚合物的Tg（45℃）时，乳胶粒子仍保持其基本形状，SiO2粒子黏附在乳胶粒子周围。

Some polymer emulsions （methyl methacrylate-butyl acrylate-methylacrylic acid copolymer） with carboxyl group were designed to modify SiO2 nanoparticles. And the composite particles were characterized by TEM, IR, TGA, contact angle and size analysis. The results showed that through physical and chemical absorption during stirring, the copolymer latexes with carboxyl group had an effect on modifying and dispersing the silica nanoparticles with the size of 15 - 20nm. When the compound temperature（65℃ ） was higher than the modified polymer Tg （45℃）, soft polymer latex particles deform and adhere around the silica nanoparticles. Then polymer latexes coated the silica particles through carboxyl chemical bond adsorption; When the compound temperature （25℃） was lower than Ts （45℃） of polymer, latexes remained their basic shape,and silica nanoparticles adhered to the surface of latex particles.