Morphology of gas-assisted and conventional injection molded polycarbonate/polyethylene blend

The skin-core structure of the gas-assisted and conventional injection molded polycarbonate (PC)/polyethylene (PE) blend was investigated. The results indicated that both the size and the shape of the dispersed PC phase depended not only on the nature of PC/PE blend and molding parameters, but also on its location in the parts. Although the gas-assisted injection molding (GAIM) parts and conventional injection molding (CIM) part have the similar skin-core structure, the morphology evolution of PC phase in the GAIM moldings and the CIM moldings showed completely different characteristics. In the section perpendicular to the melt flow direction, the morphology of the GAIM moldings included five layers, skin intermediate layer, subskin, core layer, core intermediate layer as well as gas channel intermediate layer, according to the degree of deformation. PC phase changed severely in the core layer of GAIM moldings, as well as in the subskin of CIM moldings. In GAIM parts, PC phase in the core layer of the nongate end changed far more intensely and aligned much orderly than that in the gate end. The morphology of PC phase in the GAIM part molded with higher gas pressure changed more severe than that in the GAIM part molded with lower gas pressure. In a word, PC phase showed more obvious fibrillation in the GAIM moldings than that in the CIM moldings. (c) 2006 Wiley Periodicals, Inc.