LIQUID-CRYSTALLINE EPOXIDE THERMOSETS

Highly ordered networks were produced by copolymerization of a low mol ecular weight liquid crystalline (LC) diepoxide with an aromatic diami ne. A series of aromatic diamines was synthesized and their Polymeriza tion reaction with the LC-diepoxide was studied by means of differenti al scanning calorimetry. By adjusting the melting point of the crossli nking agents an eutectic LC mixture was found on which all the physica l measurements were carried out. The degree of order of a certain dye guest in the polymer networks as determined by UV-dichroism was 0.76. Birefringence measurements have confirmed that about the same level of ordering can be maintained up to the thermal degradation point (i.e., 300 degrees C). Microscopy and X-ray studies have revealed that the e poxy-amine mixture is transformed from a nematic to a smectic phase, a s a result of the polymerization reaction at 120 degrees C.