紫外光可固化丙烯酸改性聚氨酯(PUA)的ESCA及SEM研究

丙烯酸改性聚氨酯是一类性能优良的紫外光可固化性聚合物。纵观其大量文献报道,多为各种不同用途的专利,而对其物理性能及形态结构方面的基础理论研究却较为薄弱。Wadhwa和Walsh用电子显微镜及动态粘弹谱仪研究了TDI型PUA的微相结构,认为体系为软、硬段均匀混合的均相结构。Cooper等人研究了一系列PUA的动态力学性能,证明其多为两相结构。

ESCA AND SEM STUDIES OF UV CROSSLINKABLE POLYUR- ETHANE ACRYLATES

In this work,ESCA and SEM have been used to characterize the surface and bulk micro-phase morphology, surface chemical composition and the composition of polyether soft segment and TDI-HEMA hard segment based on two TDI-HEMA-PPO types of UV cured polyuretha-ne acrylates. The experimental results show that: (1) the microphase morphology of UV cured polyurethane acrylates strongly relies on the composition of soft and hard segments. Increasing the content of polyether soft segment, the extent of microphase seperation increased; (2) the surface elemenal composition is different from the bulk elemental composition; (3) the T-HE-PP 210 system with apparent microphase seperation regulates the general rule that the soft segment in segmented copolymers is abundant at the surface due to the limitation of surface energy. Increasing the inspecting depth, the composition of soft and hard segments of T-HE-PP 204 system which appears as one phase morphology does not change.