The influence of UHMWPE with varying morphologies on the non-isothermal crystallization kinetics of HDPE

Abstract

The current study aims to examine how the morphology of ultra-high molecular weight polyethylene (UHMWPE) particles impacts the kinetics of non-isothermal crystallization in high-density polyethylene (HDPE). To prepare blends of HDPE and UHMWPE, melt blending is utilized. High-temperature melting and subsequent shearing are used to cause the morphological changes in UHMWPE particles. The morphological evolution of UHMWPE particles is observed utilizing scanning electron microscopy (SEM). The non-isothermal crystallization kinetics of HDPE with varying UHMWPE morphologies are investigated using the Jeziony and Mo methods. The nucleation activity of UHMWPE particles in HDPE crystallization is assessed using the Dobreva and Gutzow model. Furthermore, the crystallization activation energy of HDPE blends is evaluated using the Friedman model. The results exhibit that after undergoing high-temperature melting, the UHMWPE particles underwent significant morphological changes, leading to enhanced interaction with the two phases and reduced nucleation activity. Additionally, it can increase the crystallization activation energy, which causes a decrease in the HDPE crystallization rate. However, subsequent shearing has crushed the UHMWPE particles into smaller pieces, enhancing their nucleation activity, decreasing the activation energy required for crystallization and increasing the HDPE crystallization rate.