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

✍ Scribed by Ning Luo; De-Ning Wang; Sheng-Kang Ying

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 329 KB
• Volume: 34
• Category: Article
• ISSN: 0887-624X
• DOI: 10.1002/(sici)1099-0518(199608)34:11<2157::aid-pola8>3.0.co;2-w

✦ Synopsis

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(propy1ene 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 13C-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. 0 1996