Abstract:Through superfine pulverization and modification, heavy calcium carbonate powder , a kind of common filling agent, can be changed into superfine heavy calcium carbonate (SHCC) powder, which is a sort of function material with excellent prop erties. The authors collected SHCC from calcite mines of western Hubei. First, the authors tested different surface modification methods for SHCC, defined the types and dosages of modification agents, found out the conditions of modification and appraised the results of tests. In the modification process, the authors applied two kinds of surface chemical covering methods, i.e., dry method and wet method, to change the surface properites of the SHCC, and used metal ester coupling agent and silane finish as surface modification agents to perform the test acco rding to different dosages of the agents under various conditions. In the final test, the SHCC was changed from lyophilic to lyophobic. The authors decided the better test plan for the surface modification of SHCC by comparing and appraising the whitenesses, grain sizes and infrared spectral features of the SHCC. At the second step, the authors filled a few kinds of modified SHCC powder which were treated with different surface modification agents into the polypropylene plastics, and then produced a few kinds of compound polypropylene plastics by means of the compound shaping skill. Through comparing the properties of different kinds of compound polypropylene plastics, the authors conclude that (1) the functions of compound polypropylene plastics filled with modified SHCC were better than those of polypropylene plastics not filled with modified SHCC except for tension intensity, and (2) the functions of polypropylene plastics filled with the SHCC which was modified by metal ester coupling agent are better than those of polypropylene plaastics filled with the SHCC which was modified by silane finish.