OBSERVATION OF BANDED SPHERULITES IN WATER-ASSISTED AND CONVENTIONAL INJECTION MOLDED LLDPE/HDPE BLENDS

摘要

The crystal morphologies of linear low-density polyethylene (LLDPE) and its miscible blends with high-density polyethylene (HDPE) obtained by water-assisted injection molding (WAIM) and conventional injection molding (CIM) were examined. It was found that banded spherulites formed in both WAIM and CIM pure LLDPE parts. In the CIM parts, a clear banding to non-banding morphological transition occurred for LLDPE upon blending with HDPE. However, for the WAIM parts, banded spherulites of LLDPE still formed in both outer and inner zones upon blending with HDPE, but the bands became irregular. In the core zone of the WAIM parts, a clear banding to non-banding morphological transition for LLDPE was observed when the HDPE content was increased to 30 wt%.