Thermal and Chemical Resistance Behavior of Cured Epoxy Based on Diglycidyl Ether of Bisphenol-A And Thiol Treated Liquid Polysulfide Blends

In the present study five blends of Diglycidyl ether of bisphenol-A and thiol terminated liquid polysulfide with varying amount of polysulfide (i.e. 10 to 50 phr) were synthesized by physical mixing at 90 o C and synthesized blends were cured with phthalic anhydride. Interaction among epoxide group of DGEBA, -SH group of polysulfide and anhydride group of curing agent discussed through FT-IR analysis. The TGA studies revealed a decrease in thermal stability and activation energy (114.35 - 73.04 kJ/mole) with increase in polysulfide content. Volume resistivity decreases from 5.34 × 10 15 to 3.83 × 10 11 ohm-cm with increase in polysulfide content in the blends. The study of chemical resistance for various acids, alkalies to distilled water, sea water, xylene, ethanol, methyl ethyl ketone and acetone indicated that chemical resistance of blends decreased with increase in polysulfide content. Scanning electron microscopy (SEM) indicated the presence of two-phase morphology in the blends.