CRYSTALLIZATION BEHAVIOR OF POLYPROPYLENE FILLED WITH SURFACE-MODIFIED TALC

Talc-filled polypropylene (PP) composites were prepared by extrusion i n a wide composition range (0-40 wt %). To improve the affinity relati on between talc and the PP matrix, we modified the talc surface with s ilane coupling agents. Differential scanning calorimetry investigation s on test samples, prepared by injection moulding, revealed that the t alc content and its surface modification had a pronounced effect on th e crystallization behavior of the filled PP composites. The experiment al results indicate that a talc concentration of 2 wt % strongly affec ts the nonisothermal crystallization process of the PP, especially whe n talc is silane treated. Isothermal crystallization experiments on sa mples with minimum amounts of talc (2 wt %) revealed an improved nucle ation activity with silane-treated talc. (C) 1996 John Wiley & Sons, I nc.