SYNTHESIS AND PHOTOINITIATED POLYMERIZATION OF LIQUID-CRYSTALLINE DIEPOXIDES

Four different liquid crystalline diepoxides were synthesized. Replace ment of a methylene group by an oxygen atom in the spacer segment of t he molecule decreased the thermal stability of the mesophase. In order to produce highly anisotropic networks, these compounds were cationic ally photopolymerized in the nematic phase. Differential scanning calo rimetry and Fourier transform infra-red were used to monitor the polym erization. The degrees of conversion calculated from both techniques w ere in good agreement with each other. The replacement of a methylene group by an oxygen atom in the spacer part of the molecule also increa sed the rate of the polymerization reaction. Post-curing was sometimes necessary to produce highly stable networks. Furthermore, some result s suggest that liquid crystalline nematic ordering increases the polym erization rate.