The retarded recovery of disentangled state by blending HDPE with ultra-high molecular weight polyethylene

摘要

Previous studies have shown that shear-induced disentanglement of polyolefins can realize on line. However, it is difficult to realize "in pellet" disentanglement for linear polyolefins. This work tried to retard the recovery of disentanglement of HDPE by adding small amount of UHMWPE. Results showed that shear can induce HDPE/UHMWPE blends disentanglement to a large extent. The total re-entanglement time of blends was as much as twice than HDPE, the half time of re-entanglement of H/U3 and H/U5 climbed up from 140 to 710 and 633s respectively. It is highly possible to realize "in pellet" disentanglement to meet the post processing. Furthermore, it was interestingly found that the viscosity of blend would be lower than that of HDPE at a certain time range under the conditions of this experiment. The reduced entanglement enabled the higher chain mobility, which facilitated the formation of the more perfect crystals.