High speed injection molding of high density polyethylene - Effects of injection speed on structure and properties

被引：13

作者：

Jiang, Kun ^{[1
]}

Yu, Fei-long ^{[1
]}

Su, Run ^{[1
]}

Yang, Jing-hui ^{[1
]}

Zhou, Tian-nan ^{[1
]}

Gao, Jian ^{[1
]}

Deng, Hua ^{[1
]}

Wang, Ke ^{[1
]}

Zhang, Qin ^{[1
]}

Chen, Feng ^{[1
]}

Fu, Qiang ^{[1
]}

机构：

[1] Sichuan Univ, Coll Polymer Sci & Engn, State Key Lab Polymer Mat Engn, Chengdu 610065, Peoples R China

来源：

CHINESE JOURNAL OF POLYMER SCIENCE | 2011年 / 29卷 / 04期

基金：

中国国家自然科学基金;

关键词：

High speed injection molding; High density polyethylene; Tensile properties; Extended chain crystals structure; Large folded chain crystals; TENSILE PROPERTIES; MECHANICAL-PROPERTIES; MOLECULAR-WEIGHT; MODULUS; POLYPROPYLENE; COMPOSITES; STRENGTH; BEHAVIOR; POLYMER; YIELD;

D O I：

10.1007/s10118-011-1049-3

中图分类号：

O63 [高分子化学（高聚物）];

学科分类号：

070305 ; 080501 ; 081704 ;

摘要：

Thin wall samples of high density polyethylene (HDPE) were prepared via injection molding with different injection speeds ranging from 100 mm/s to 1200 mm/s. A significant decrease in the tensile strength and Young's modulus was observed with increasing injection speed. In order to investigate the mechanism behind this decrease, the orientation, molecular weight, molecular weight distribution, melt flow rate, crystallinity and crystal morphology of HDPE were characterized using two-dimensional wide-angle X-ray diffraction (2D-WAXD), gel permeation chromatography (GPC), capillary rheometry and differential scanning calorimetry (DSC), respectively. It is demonstrated that the orientation, molecular weight, molecular weight distribution, melt flow rate and crystallinity have no obvious change with increasing injection speed. Nevertheless, the content of extended chain crystals or large folded chain crystals was found to decrease with increasing injection speed. Therefore, it is concluded that the decrease in tensile properties is mainly contributed by the reduced content of extended chain crystals or large folded chain crystals. This study provides industry with valuable information for the application of high speed injection molding.

引用

页码：456 / 464

页数：9