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

Abstract

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.

Effect of Melt and Mold Temperatures on the Solidification Behavior of HDPE during Gas‐Assisted Injection Molding: An Enthalpy Transformation Approach

“…In our recent researches, the role of flow characteristics (especially the shear rate fields) associated with the gas penetration process on the morphological formation in gas-assisted injection molded parts of polyethylene, [24,25] poly(propylene), [26] polycarbonate/polyethylene blend, [5,27,28] as well as glass fiber reinforced polyamide [29] was extensively investigated. The hierarchical structures (i.e., crystalline structure and oriented structure) in GAIM parts, quite different from those in CIM process, were observed.…”

“…was negligible as compared with the latent heat released during the solidification process. [27] The polymer phase transition is assumed to take place over a temperature range T 1 to T 2 , also known as the mushy zone, [32] with T f ¼ (T 1 þ T 2 )/2 as a reference temperature in this case. The latent heat of phase change will be released simultaneously within the solidification process.…”

Transcrystallinity in a Polycarbonate(PC)/Polyethylene(PE) Blend Prepared by Gas-Assisted Injection Molding: A New Understanding of Its Formation Mechanism

“…The length and diameter were 190 mm and 10 mm, respectively, which are the same as those in the literature. [7] …”

“…[7] Besides, we also found that PC fibrils are derived from a few PC particles, which are deformed during gas penetration. [8] Thus, we wonder whether these fibrils would induce other interesting morphology, namely transcrystallinity.…”

Conductivity and phase morphology of carbon black-filled immiscible polymer blends under creep: an experimental and theoretical study

“…The understanding and control of the blend composite morphology development in mixing equipment where two or more immiscible polymers are melt blended is a long-lasting dream of researchers in the field of polymer processing. [15][16][17][18][19][20][21] The structure of conductive pathways and the phase morphology in the final material are significantly influenced by the shear or elongation forces applied during processing. [22][23][24][25][26][27][28][29] Therefore, understanding the effects of a defined flow field on composite structures and their phase morphology evolution is vital for the preparation of conductive polymer composites with desired electrical properties.…”