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.