纳米碳酸钙在醇相中的表面处理及其原位复合材料制备

Study on Surface Modification of Nano-Calcium Carbonate in Ethanol and Its In-situ Composite

在醇相中用具反应活性的甲基丙烯酸(MAA)对纳米碳酸钙(CaCO_3)进行表面处理,制成分散体系。研究了MAA 用量、pH 值、分散时间、温度等对分散体系稳定性及形态的影响。TEM 分析表明,在醇相中用10份的 MAA 对纳米 CaCO_3粒子进行处理,可以达到较好的分散效果;在原位本体聚合制得的聚苯乙烯(PS)/纳米 CaCO_3复合材料中,纳米 CaCO_3粒子能均匀分散,粒径在100 nm 以内。纳米 CaCO_3能较好地增韧增强 PS/纳米 CaCO_3复合材料,含7%～8%纳米 CaCO_3的原位复合材料的冲击强度和拉伸强度分别为纯 PS 的258%和311%。

Nano-calcium carbonate （nano-CaCO3） particle was surface modified with methacrylic acid （MAA） in a medium of ethanol. The carboxyl groups of MMA were anchored on the surface of nano- CaCO3 particle and the double bonds were preserved for further reactions. The effects of the dosage of MMA, the pH of the medium, treating time and temperature on the morphology of the modified particles and the stability of the dispersion were investigated in order to optimize modification process. Polystyrene/nano-CaCO3 composites were prepared via in-situ bulk polymerization. TEM showed that nano-CaCO3 particles with diameters less than 100 nm were distributed homogeneously in polymer matrix. When the content of nano-CaCO3 was between 7 % and 8 %, the toughness and tensile strength of the composites reached their maxima, which were 258 % and 311% that of neat polystyrene, respectively.