PREPARATION OF HIGH MODULUS POLYPROPYLENE SHEET BY THE ROLLER-DRAWING METHOD

被引:4
作者
KAITO, A
NAKAYAMA, K
KANETSUNA, H
机构
[1] Research Inst for Polymers &, Textiles, Tsukuba, Jpn, Research Inst for Polymers & Textiles, Tsukuba, Jpn
关键词
CRYSTALS - Orientation - PLASTICS SHEETS - Mechanical Properties;
D O I
10.1295/koron.42.231
中图分类号
O63 [高分子化学(高聚物)];
学科分类号
070305 ; 080501 ; 081704 ;
摘要
A polypropylene sheet was drawn through a pair of heated rollers and mechanical properties, molecular orientation and microstructure of the roller-drawn sheet were investigated. With increasing draw ratio, Young's modulus, dynamic storage modulus, and tensile strength increased and the intensity of tan delta peak in the beta -dispersion region decreased. The degree of orientation of crystal c-axis increased with draw ratio and reached a constant value above draw ratios of 7-9, while the degree of orientation of amorphous molecular chains increased with increasing draw ratio even in the high draw ratio range. There is a good correlation between the degree of orientation and the dynamic storage modulus measured below beta -dispersion temperature. The increase of the fraction of tie molecules and crystalline bridges, however, plays an important role in the improvement of the modulus above the beta -dispersion temperature.
引用
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页码:231 / 239
页数:9
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