CRYSTALLIZATION BEHAVIOR OF POLYPROPYLENE FILLED WITH CALCIUM-CARBONATE OF VARIOUS SHAPE

Calcium carbonate of various particle shape (spheric, cubic, needle-shaped type) and polypropylene (PP) were mixed on a two roll mill and the mixture was pressed into plates. The effect of particle shape on the crystallization behavior of PP/CaCO3 composites, such as crystallization peak temperature (T(MAX)), crystallized pattern, etc., was investigated with differential scanning calorimetry measurements. The value of T(MAX) is explained by the total surface area of added CaCO3 Particles; T(MAX) of needle-shaped series is larger than that of cubic or spheric ones. T(MAX) of various shaped CaCO3-filled PP totally depends on the cooling rate and maximum temperature in the non-isothermal crystallization, respectively.