具有四重氢键基元聚氨酯的合成与流变学行为

Synthesis of polyurethanes with quadruple hydrogen bonding recognizing units and their rheological performance

利用羟基和异氰酸酯基的反应,以聚乙二醇(PEG)为柔性链段,合成了一系列三官能度,具有四重氢键基元(Upy)的聚氨酯(PU)。由于Upy基元自识别形成的四重氢键作用,PU分子间可形成交联网络结构,其热性能和力学性能都随着Upy含量增加而提高,并且其熔融流变行为明显表现出温度和频率依赖性。基于高温下四重氢键基元的破坏,对这种流变学行为进行了解释。

A series of polyurethanes with quadruple hydrogen bonding recognizing units （Upy units） at both the ends and the middle of the chain was synthesized based on the reaction between hydroxyl group and isocyanate group using polyethyleneg glycol as the soft chain.The polymers formed interlinked network structures due to the formation of quadruple hydrogen bonding and displayed higher glass transition temperature and better mechanical properties with higher content of Upy units.The rheological performance of the polymers indicated that the complex viscosity was depended on both temperature and frequency.Such rheological performance was explained based on the disruption of quadruple hydrogen bonds at high temperature.