Phase Structures, Viscoelasticity and Impact-energy Absorbability of CTBN / Epoxy Network Polymer Alloys

摘要

Carboxyl-terminated butadiene acrylonitrile (CTBN) liquid rubber / epoxy (diglycidyl ether of bisphenol-A: DGEBA) /diamino diphenyl methane (DDM) network polymer alloys, in which CTBN was the major component (60 wt%), were formulated. In cases where acrylonitrile (AN) was 10 ～ 18 mol% as copolymerization ratio in CTBN, the polymer alloys showed phase separated morphologies consisting of rubber-rich continuous phases and epoxy-rich dispersed phases with the size of micrometer or sub-micrometer. In the mean time, the polymer alloy where AN was 26 mol% in CTBN showed good compatibihty among components. Scanning probe microscopy revealed the existence of heterogeneous nano-phase structures in the polymer alloy. Pulsed NMR indicated that the molecular mobility of CTBN was strongly constrained in the polymer alloy including CTBN with AN 26 mol%, and the interface between the CTBN and the epoxy increased with decreasing the phase size. The nano-phase structure and the thick interface would be the source of the broad glass-transition temperature region of the network polymer alloy, which played an important role to give the excellent impact-energy absorbability in a broad range of temperature.