Study on the processability of UHMWPE filled with different size distribution calcium carbonate particles

Two kinds of different size distribution calcium carbonate (CaCO₃) particles were blended and filled into ultra‐high molecular weight polyethylene (UHMWPE). The torque of UHMWPE/CaCO₃ samples was measured with Haake torque rheometer. The results showed that the process torque of UHMWPE/CaCO₃ samples was decreased by filling two different size CaCO₃ particles (600 and 2500 mesh) into UHMWPE, compared with the samples filled with single size CaCO₃ particles (600 or 2500 mesh). When the content of CaCO₃ in the sample reaches 30 wt%, UHMWPE filled with different size distribution CaCO₃ particles showed the largest decrease in torque compared with the samples filled with single size CaCO₃ particles. We also studied the torque of UHMWPE samples at different temperatures. The results showed that flow activation energy and flow activation entropy of UHMWPE samples filled with different size distribution CaCO₃ particles increase significantly. The result where flow activation entropy increased was used to explain the phenomenon that the process torque decreases when UHMWPE filled with different size distribution CaCO₃ particles. POLYM. COMPOS., 36:1807–1812, 2015. © 2014 Society of Plastics Engineers