Morphology Evolution and Mechanical Property Enhancement of Linear Low‐density Polyethylene by Adding Disentangled Ultrahigh Molecular Weight Polyethylene

Ultra-high molecular weight polyethylene (UHMWPE) and linear low-density polyethylene (LLDPE) with different ratios were melt-blended in an internal mixer. Results of rheological tests and scanning electron microscopy indicate that the blends are well miscible in the range of small addition amount of UHMWPE. The content of UHMWPE is suggested to be less than 5.0 wt%, to guarantee good compatibility of biphasic blends. Differential scanning calorimetry studies indicate that co-crystallization occurs between UHMWPE and LLDPE. The crystallinity increases with the increase of UHMWPE as a nucleating agent. As a result, an improvement in mechanical properties is achieved. When the addition amount of UHMWPE is 5.0 wt%, the impact strength, breaking elongation, Young's modulus, and tensile strength are significantly increased by 27%, 25%, 75%, and 21% respectively.