Synthesis and Characterization of Epoxy-Containing Schiff-Base and Phenylthiourea Groups for Improved Thermal Conductivity

Three new diglycidyl monomers bearing phenylthiourea and azomethine groups were synthesized using 4,4′-diaminodiphenyl ether, 4,4′-diaminodiphenylmethane, and 4,4′-diaminodiphenyl sulphone as starting materials. The monomers were characterized through IR and 1H-NMR spectroscopic analysis. The monomers were blended with epoxy based trickle impregnation resin (Dobeckot 605) and cured. The cured resins were subjected to TGA and DSC analysis. Presence of 3% by weight of the diglycidyl monomers bearing thiourea and azomethine groups in the cured blends did not alter the thermal stability but increased the thermal conductivity. The thermal conductivity of the cured blends were approximately 1.9 times higher than that of epoxy-based trickle impregnation resin and comparable with the epoxy-based resin filled with 20% inorganic fillers.