文献类型：期刊文献

英文题名：Study on sequence distribution of segmented poly(urethane urea)s by C-13-NMR spectroscopy: Effect of polymerization procedures

作者：Luo, N; Wang, DN; Ying, SK

机构：[1]E CHINA UNIV SCI & TECHNOL,INST MAT SCI & ENGN,SHANGHAI 200237,PEOPLES R CHINA

年份：1996

卷号：34

期号：11

起止页码：2157

外文期刊名：JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY

收录：;WOS:【SCI-EXPANDED(收录号:WOS:A1996UX70500012)】；

语种：英文

外文关键词：poly(urethane urea); sequence distribution; C-13-NMR

摘要：The segmented poly(urethane urea) copolymers were synthesized by one- and two-step polymerization procedures. The copolymers were based on 4,4'-diphenylmethane diisocyanate, 3,5-diethyltoluene diamine, and ethylene oxide-capped poly(propylene oxide) diol. The mean sequence lengths of polyurethane soft block and polyurea hard block as well as the sequence distribution of the hard block in the copolymers were estimated from the signals of aromatic carbons in C-13-NMR spectra. The results indicated that two-step polymerization led to longer mean sequence lengths and broader hard block sequence distribution than one-step polymerization did. (C) 1996 John Wiley & Sons, Inc.