Surface Characteristics of Heavy Calcium Carbonate Modified by Polymer Grafting
苯乙烯接枝聚合改性的重质碳酸钙表面特征分析及形成机理

A new process of polymer grafting modification of CaCO3 is proposed, which combines the action of mechanical force, thermal and chemical effects. The modification time is reduced greatly and the modification effect is improved. Infrared spectrum (IR), gel permeation chromatography (GPC), X photoelectron spectrum (XPS) and thermogravimetry (TG) analyses are employed to characterize the modified surface of heavy calcium carbonate by styrene grafting. It is proven that chemically absorbed multi-layer polystyrene exists on the surface of the modified particles apart from grafted polystyrene. The primary surface characteristics of heavy calcium carbonate are deduced based on physico-chemical analyses. Radical polymerization is regarded as the primary modification mechanism.