Enhancement of the thermal conductivity of aluminum oxide–epoxy terminated poly(dimethyl siloxane) with a metal oxide containing polysiloxane

Aluminum oxide containing poly(dimethyl-methylvinyl)siloxane (PMDMS:Al2O3) was synthesized and blended with epoxy-terminated dimethylsiloxane (ETDS) to fabricate a thermally conducting composite. PMDMS:Al2O3 was added to provide interfacial interactions between the Al2O3 and polymer matrix. The PMDMS:Al2O3 containing composites revealed more enhanced thermal conduction properties because of the strengthened interfacial bonding at a fixed filler concentration. The conductivity as a function of the filler concentration was correlated with Agari’s models. Based on the coefficient obtained from Agari’s model, PMDMS:Al2O3 affected the formation of the conducting path in the composite. The results indicated that the presence of PMDMS:Al2O3 would help to establish a conducting path compared to compounds without it. All composites showed a decrease in thermal conductivity with increasing operating temperature. As expected, the PMDMS:Al2O3 containing composite (P-ETDS/Al2O3) showed more enhanced thermal conductivity than those without, regardless of the operating temperature.