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.