Effect of graphene oxide on the kinetics of the radical polymerization of styrene

Abstract

Nanocomposite materials based on polystyrene and either graphene oxide (GO) or functionalized graphene oxide (F-GO), were produced using the in situ radical polymerization technique, from graphite oxide, styrene monomer and benzoyl peroxide, initiator. XRD data revealed that graphite oxide had been transformed to graphene oxide during polymerization. Reactions kinetics was followed gravimetrically and it was found that the presence of hydroxyl groups on the surface of GO results in scavenging of the primary radicals formed from the decomposition of the initiator, reducing thus the initiator efficiency and as a result the reaction rate. The number average molecular weight of the polymer formed was increased, together with the polydispersity of the MWD. Furthermore, F-GO was produced after reaction of the surface hydroxyl groups in GO with a silane-modifying agent. The effect on the polymerization kinetic turned out to have been moderated or even cancelled. An enhancement in the thermal stability of the polymer was observed by the incorporation of either GO or F-GO.