碳酸钙晶须的制备与填充性能

研究了用CaCl2—MgCl2—Mg(OH)2体系碳化制备CaCO3晶须的过程。结果表明，反应体系中初始的n(CaO)／n(MgCl2)及未转化完全的Ca(OH)2粒子对最终所得产物的形态有决定性作用。在较高的初始n(CaO)／n(MgCl2)下，所得粉体由CaC0。球形粒子、玉米棒状晶须和少量光滑晶须构成。在较低的n(CaO)／n(MgCl2)下，晶须的形成过程不同于高n(CaO)／n(MgCl2)下的情况，可以制备出由大量光滑晶须和少量球形粒子构成的粉体材料。与纳米CaCO3粒子相比,Ca—CO3晶须在一定填充量时对聚丙烯具有较好的增强增韧作用，前者在高含量时具有明显的增韧作用，但会引起拉伸强度下降。

Preparation and Filling Performance of Calcium Carbonate Whiskers

This paper investigated the synthesis and formation process of calcium carbonate whiskers by the carbonation of CaCl 2 MgCl 2 Mg(OH) 2 system. The results indicate that the shape of final product is subject to the initial n (CaO)/ n (MgCl 2) and the Ca(OH) 2 particles present in the system before carbonation reaction. The obtained product is composed of CaCO 3 spherical particles, corrn shape whiskers and smooth whiskers under higher initial n (CaO)/ n (MgCl 2), and smooth whiskers under lower initial n (CaO)/ n (MgCl 2) . The tensile strength of polypropylene (PP)/CaCO 3 whiskers composite material is very close to that of pure PP and higher than that of PP/nanometer composite. CaCO 3 whiskers and nanometer CaCO 3 particles can obviously increase toughness of the composite when the filling amount is over about 8%, but the effect of the later is stronger than that of the former. At about 2% of filling amount, unmodified CaCO 3 whiskers can increase the tensile strength and toughness of the composite.