NEW TYPES OF LIQUID-CRYSTALLINE EPOXY-RESINS CURED BY A MESOGENIC HARDENING COMPOUND

The new epoxy resins, EPD-CAA10 and EPTB-CAA10, were synthesized by re acting stoichiometrically the diepoxides, 4,4'-bis(2,3-epoxypropoxy)bi sphenol A (EPB) and is-2,3-epoxypropoxy)-3,3',5,5'-tetramethylbiphenol (EPTB), respectively, with a mesogenic hardening compound, 4,4'-bis(o mega-carboxydecanoxy)azoxybenzene (CAA10), using tri-n-butylamine as a catalyst. The reaction procedures and the mesogenic phase transitions for the two epoxy resins were studied by the use of infra-red (i.r.), spectroscopy, differential scanning calorimetry (d.s.c.) polarizing m icroscopy and X-ray diffraction spectroscopy. It was found that both o f the differential EPB-CAA10 and EPTB-CAA10 systems had a mesophase wh ich was functionalized by the mesogenic hardening compound; EPB-CAA10 showed a smectic-like mesophase between 70 and 90 degrees C when the p olymer was not gelated but had no mesophase when gelated, while EPTB-C AA10 also had a smectic-like mesophase when not gelated, but showed a nematic phase when gelated. Copyright (C) 1996 Published by Elsevier S cience Ltd.