摘要
通过定量核磁共振碳谱(13C-NMR谱)、广角X射线衍射(WAXD)和差示扫描量热分析(DSC)对不同数均相对分子质量的环氧乙烷-四氢呋喃无规共聚醚P(E-co-T)的序列结构和结晶性能进行了研究;以不同的P(E-co-T)无规共聚醚制备了一系列热固性聚氨酯弹性体,并对其网络结构和力学性能进行了研究。定量13C-NMR确认了P(E-co-T)无规共聚醚分子链中存在[THF]n微嵌段结构,并计算了不同相对分子质量P(E-co-T)无规共聚醚中微嵌段的含量。WAXD和DSC结果表明,等摩尔组成的P(E-co-T)无规共聚醚在-40℃时发生了结晶,且不同相对分子质量P(E-co-T)无规共聚醚的结晶能力与其分子链中[THF]n微嵌段结构的含量密切相关。聚醚聚氨酯弹性体的力学测试结果则表明,20℃和60℃时,随着聚醚相对分子质量的增加,聚氨酯弹性体的拉伸强度逐渐降低,断裂延伸率逐渐增加;然而,-40℃时则表现出截然相反的变化趋势。-40℃时聚醚聚氨酯弹性体结晶能力的差异是导致其低温力学性能不同的主要原因。
The sequence structure and crystallization behavior of the ethylene oxide-tetrahydrofuran random copolymer, P（E-co-T）, were investigated by the quantitative 13C-NMR spectra, WAXD, and DSC. The thermostat polyurethane elastomers were prepared with P（E-co-T） copolyether, and the network structure and mechanical properties of the resultant polyurethane elastomers were studied. Based on the quantitative 13C-NMR, the existence of the micro-blocks [THF]n（n≥3） in P（E-co-T） chains was determined, and the content of [THF]n in P（E-co-T） copolyethers was calculated. The WAXD and non-isothermal DSC results of the P（E-co-T） copolyether reveal that the crystalline formed by the THF units is observed at -40 ℃, and the dependence of the molecular weight on crystallization capability for the P（E-co-T） copolyether was closely related to the content of the micro-blocks [THF]n in P（E-co-T） chains. The results of the mechanical properties of the polyether polyurethane elastomers reveal that the tensile stress decreases and strain at break increases with molecular weight of the prepolymer, while an opposite trend is obtained at -40 ℃ for the polyether polyurethane elastomers, which is caused by the different crystallization capability at -40 ℃.
作者
邹业成
张永丽
翟进贤
杨荣杰
Yecheng Zou1, Yongli Zhang1,2, Jinxian Zhaii, Rongjie Yanga(1. School of Material Science ＆ Engineering, Beijing Institute of Technology, Beijing 100081, China ; 2. Xi ＇ an North Hui ＇ an Chemical Industry Co. Ltd , Xi ＇ an 710302, Chin)
出处
《高分子材料科学与工程》
EI
CAS
CSCD
北大核心
2018年第3期22-29,共8页
Polymer Materials Science & Engineering
关键词
无规共聚醚
序列结构
结晶行为
聚氨酯弹性体
力学性能
random eopolyether
sequence structure
crystallization behavior
polyurethane elastomer
mechanical properties
