乙烯脲改性水性聚氨酯脲的制备与性能

采用一种新型的扩链剂乙烯脲(EU),在聚氨酯硬段引入具有刚性环状二取代脲基团,通过控制脲含量、交联度以及软段相对分子质量来制备一系列的EU改性水性聚氨酯脲(PUU-EU),并利用透射电镜(TEM)、广角X射线衍射(WAXD)、动态力学机械分析(DMA)、热失重分析(TGA)等测试方法,系统地研究PUU-EU微观结构与氢键化程度、微相分离、耐热性、力学强度的关系,并与1,4-丁二醇(BDO)扩链制备的水性聚氨酯(WPU)进行对比。结果表明,在一定范围内,PUU-EU随脲含量增加,其氢键化程度愈发完善,微相分离程度随之增加,力学强度逐步提高。

The Waterborne Polyurethane Urea Preparation and Properties Modified by Ethylene Urea

Disubstituted cyclic urea group was introduced in polyurethane hard segment by using a novel chain extender-ethylene urea （EU）. A series of the EU modified aqueous polyurethane urea dispersions（PUU-EU） was prepared by controlling the urea content, degree of crosslinking and the soft segment molecular weight. The relation- ship between microstructure of PUU-EU and degree of hydrogen bonding, microphase separation, heat resistance, mechanical strength, etc. was charactered by TEM,WAXD, DMA,TGA. It was compared with WPU which was u- sing BDO as chain extender. The experimental resuhs showed that, with urea content increasing in PUU-EU sam- ples, the degree of hydrogen bonding become increasingly perfect, microphase separation also increased and the me- chanical strength improved gradually.