Diisocyanate-modified graphene oxide/hydroxyl-terminated silicone rubber composites for improved thermal conductivity

Abstract

Graphene oxide (GO) treated with dicyclohexylmethane-4,4′- diisocyanate (HMDI) was first synthesized and termed FGO. Fourier transform infrared spectroscopy (FTIR), energy dispersive spectrometer(EDS), and X-ray diffractometry (XRD) were carried out to characterize the FGO structure. The results showed that the dispersibility of FGO in solvent was improved. Nuclear magnetic resonance(NMR) crosslinking density tester measuring crosslink density, room-temperature vulcanized silicone rubber was prepared with hydroxy-terminated polydimethylsiloxane (HPDMS) treated with FGO as a co-crosslinking agent, resulting in FGO/HPDMS. The FGO/HPDMS composites were proven to be successfully prepared by FTIR and XRD. The effects of the addition of different amounts of FGO on the crosslinking density, thermal conductivity, and mechanical properties before and after hot air aging of the FGO/HPDMS composites were investigated. As the amount of FGO was increased, the thermal conductivity and mechanical properties of the FGO/HPDMS composites increased. At 20% FGO addition, the corresponding thermal conductivity of the FGO/HPDMS composites was 1.24 W/mK.