聚醚型聚氨酯中软硬段之间的氢键作用∗

摘要

Aliphatic polyether⁃based polyurethane( PU) prepolymer was chain⁃extended with different diol or diamine respectively. Hydrogen⁃bond of amidogen, carbonyl and other groups in polyurethane was studied with FT⁃IR spectroscopy. The hydrogen⁃bond interaction between hard and soft segment were calculated. The results showed that all the amidogen in PU with diamine extender was hydrogen bonded, and more than 1/3 hydrogen⁃bond occurred between hard and soft segment. A part of the amidogen in PU with diol extender was hydrogen bonded, and the hydrogen⁃bond interaction main occurred in hard⁃hard segment. Soft and less space steric hindrance mole⁃cular structure of chain extender was good for hydrogen bonding formation. The hydrogen bonding enhanced the film forming of PU resins as well.%将脂肪族聚醚型聚氨酯（ PU）预聚体用二元醇或二元胺扩链，制得不同结构的PU。用红外光谱研究P U中氨酯氨基（—NH—）、羰基等基团间的氢键化程度，并研究软硬段之间的氢键作用。结果表明，胺扩链PU中，氨基全部发生氢键作用，且有超过1／3的氢键作用发生在硬段与软段之间；醇扩链PU中，部分氨基发生氢键作用，且氢键作用主要发生在硬段与硬段之间。柔顺、空间位阻小的扩链剂分子结构对氢键的形成有利。氢键作用改善了PU树脂的成膜性能。