[Analysis of hydrogen bondings in polyurethane urea cured in graded temperature field by FTIR].
Hydrogen bondings in polyurethane urea elastomer, which reflect the microphase separation, have an important effect on the properties of the elastomer. The polyurethane urea elastomers, whose degree of microphase separation changed gradually, were prepared in the graded temperature field. Hydrogen bondings in them were investigated by FTIR technology. The discussions about C=O, NH, and -O- stretching vibration spectra were given. The percentage of hydrogen bonded carbonyl groups increases with the increase in the curing temperature in the thickness direction, which indicates the increase in the degree of microphase separation in it. The degree of hydrogen bonded ether oxygen atoms exhibits obvious difference in polyurethane urea with different crosslinking degree. It is this difference that leads to a contrast changing trend of the percentage of hydrogen bonded NH in different samples. Three-dimensional hydrogen bonding between urea carbonyl and NH is stronger than the hydrogen bonding between ether oxygen atoms and NH. The stretching vibration of hydrogen bonded ether group is at about 1 076 cm(-1).
Zhao
Pei-Zhong
PZ
Department of Chemistry and Materials, College of Science, Naval University of Engineering, Wuhan 430033, China. zpzgraduate@163.com
Wen
Qing-Zhen
QZ
Wang
Yuan-Sheng
YS
Zhu
Jin-Hua
JH
Hua
Xing-Yan
XY