Role of calcium carbonate morphology on thermal and mechanical properties of HDPE

Abstract

Calcium carbonate (CaCO₃) microparticles with four different morphologies, which are cubic, acicular, spindle and sphere-like, were prepared using calcium chloride (CaCl₂) and sodium carbonate (Na₂CO₃) aqueous solutions containing various additives. High density polyethylene (HDPE)/CaCO₃ composites were prepared using a HAAKE Rotational Rheometer. The thermal behaviour, mechanical properties and the rheology property were investigated and characterised by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), capillary rheometry and universal testing machine. The result shows the addition of CaCO₃ to HDPE can increase the decomposition temperature and decrease the melting temperature and crystallization temperature. Sphere-like CaCO₃ is the best form in improving the thermal stability and toughness of the composites; while the cubic CaCO₃ can cause negative effect to the toughness.