本发明提供了一种表面支链化碳酸钙的制备方法：将碳酸钙的分散液与表面处理剂混合进行酸钙反应,得到预处理碳酸钙；所述表面处理剂带有两种以上反应性官能团；将预处理碳酸钙与低聚物和引发剂进行加热混炼,得到表面支链化碳酸钙；所述低聚物的数均分子量为2000～4000；所述低聚物包括聚乙烯蜡、聚苯乙烯、聚丙烯酸和聚丙烯酸酯中的一种。本发明通过表面处理剂对碳酸钙进行预处理,使其表面带有反应性官能团,然后利用预处理碳酸钙与特定种类的低聚物进行接枝反应,在碳酸钙表面引入支链得到表面支链化碳酸钙；碳酸钙表面的支链结构与UHMWPE的结构相似度高,能够降低复合体系的熔体粘度,提高复合材料的综合性能。

The invention provides a preparation method of surface branched calcium carbonate. The method comprises the following steps: a dispersion liquid of calcium carbonate and a surface treatment agent are mixed for acid-calcium reaction, and pretreated calcium carbonate is obtained; the surface treatment agent contains two or more reactive functional groups; pretreated calcium carbonate, an oligomer and an initiator are heated and mixed, and surface branched calcium carbonate is obtained, wherein the number-average molecular weight of the oligomer is 2000-4000, and the oligomer contains one of polyethylene wax, polystyrene, polyacrylic acid and polyacrylate. Calcium carbonate is pretreated by the surface treatment agent to be provided with the reactive functional groups on the surface, then pretreated calcium carbonate and the specific type of oligomer are subjected to grafting reaction, a branched chain is introduced into the surface of calcium carbonate, and surface branched calcium carbonate is obtained. The surface branched chain structure of calcium carbonate is similar to the structure of UHMWPE, the melt viscosity of a composite system can be reduced, and comprehensive properties of a composite are improved.