Amine-modified graphene oxide as co-curing agent of epoxidized polysulfide prepolymer: Thermophysical and mechanical properties of nanocomposites

Amine-modified graphene oxide (GO) nanosheets were used to co-cure epoxy-terminated polysulfide pre polymer and fabrication of polysulfide polymer/graphene nanocomposites. GO was modified with ethylenediamine (EDA) to obtain amine-functionalized reduced GO-EDA nanosheets. Besides, epichlorohydrin reacted with disodium tetrasulfide (Na2S4) to prepare epoxide-terminated polysulfide prepolymer. Different amounts of GO-EDA nanosheets were used to fabricate EDA-cured nanocomposites. Different properties of nanocomposites were investigated consisting of structural, thermophysical, thermal and mechanical properties. Also, in-plane tensile properties of samples were evaluated by a peel approach where a film of nanocomposites was exerted onto the surface of aluminum and adhesion was evaluated via ASTM D3039. Results showed that glass transition temperature (T-g), melting temperature (T-m) and enthalpy of melting (Delta H-m) of nanocomposites increased by increasing the amount of GO-EDA nanosheets up to 0.7 wt% whereas they were not changed significantly by more increase of nanosheets. Also, using 0.7 wt% GO-EDA led to the highest thermal stability, hardness and in plane tensile properties of nanocomposites. In this field, variation of crystallinity of samples played the most important role in determining thermophysical and mechanical properties.