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Tuning Crystalline Morphology of High‐Density Polyethylene by Tailoring its Molecular Weight Distribution for Coupling with a Secondary Flow Field
Author(s) -
Zhang QuanPing,
Xia XiaoChao,
He Shan,
Feng JianMin,
Yang MingBo,
Li YinTao,
Zhou YuanLin
Publication year - 2015
Publication title -
macromolecular materials and engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.913
H-Index - 96
eISSN - 1439-2054
pISSN - 1438-7492
DOI - 10.1002/mame.201500008
Subject(s) - materials science , molding (decorative) , coupling (piping) , morphology (biology) , polyethylene , molar mass distribution , flow (mathematics) , composite material , field (mathematics) , nanotechnology , polymer , mechanics , genetics , physics , mathematics , pure mathematics , biology
Designing a material from the chain architecture to achieve a tailored crystalline morphology in a molding condition is a grand challenge. Here, the crystalline morphology of high‐density polyethylene is tuned by tailoring its molecular weight distribution for coupling with the secondary flow field under gas‐assisted injection molding (GAIM). The selected N‐PE and the tailored B‐PE have similar weight‐average molecular weights ( M w ), but the latter possesses a broader molecular weight distribution (MWD). Although a weaker flow field is triggered due to the slightly slower melt advance rate in the cavity, B‐PE is capable of better coupling with secondary flow field in comparison with N‐PE, which causes much more oriented crystals in molded parts, such as shish kebab, and shows higher orientation behaviors in the corresponding zones. These significant results provide an important step to explore the coupling of chain architectures and secondary flow field for designing desired crystalline morphology.