Rubber-modified epoxy photopolymers

The morphology of ruber modified epoxy photopolymers was found to depend on the cure conditions as well as the nature and concentration of rubber. The commercially available acrylonitrile-butadiene copolymer rubber modifiers with varying percentages of acrylonitrile content were used. They were polymerized using a photocationic initiator involving a UV exposure followed by a thermal cure. Transmission electron micrographs of osmium tetroxide stained specimens, coupled with dynamic mechanical measurements indicated that phase separation and particle size distribution depended not only on rubber concentration and compatibility, but also on the cure conditions. 

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