Crystallization, mechanical properties and thermal stability of cockleshell-derived CaCO₃ filled polypropylene

This study discusses the potential of utilizing waste cockleshell derived-CaCO₃ (CS) as filler in polypropylene (PP). Mineral fillers were prepared from cockleshell-derived CaCO₃ and used to fill polypropylene. The composites were prepared by melt blending and fabricated by injection and compression molding techniques. The effects of filler on crystal structure, crystallization and thermal degradation characteristics of filled polypropylene composites were elucidated. The cockleshell filler promoted the formation of the β-crystalline phase in PP, which improved the rigidity and toughness of the composites. However, stearic acid treatments on the filler would significantly affect the nucleation process and therefore hindered crystallization. Acceleration in thermal degradation of PP was also noted with increasing filler loading.