Amphiphilic comb-like polymer-modified graphene oxide and its nanocomposite with polystyrene via emulsion polymerization

Abstract

The synthesis of amphiphilic polymer-modified graphene oxide and its evaluation in the preparation of polystyrene nanocomposites via aqueous phase emulsion polymerization have been studied. The polymer modification was achieved via surface initiated atom transfer radical polymerization (SI-ATRP) from graphene oxide and subsequent sulphonation of the resulting brush-like polymer. Fluorimetric studies using pyrene as fluorescent probe gave a critical aggregation concentration (CAC) value of 1.29 mg/ml, comparable to that of polymeric surfactants. The surfactant was evaluated in the emulsion polymerization of styrene and on increasing the surfactant concentration from 0.5 to 2.0 wt%, the nanocomposite particle size varied from 160 to 220 nm, respectively. Nanocomposite films containing amphiphilic polymer-modified graphene surfactant show lower glass transition temperature and improved thermomechanical properties. The water contact angle of the film coated on a glass substrate increased from 84° to 124°, indicating a synergistic effect of graphene and the grafted polymer, suggesting that it was use as multifunctional additive for polymer nanocomposites.