Preparation of poly(vinyl alcohol)-grafted graphene oxide/poly(vinyl alcohol) nanocomposites via in-situ low-temperature emulsion polymerization and their thermal and mechanical characterization

Abstract

An in-situ polymerization combined with chemical grafting modification method for preparing Poly(vinyl alcohol)-grafted graphene oxide/Poly(vinyl alcohol) (PVA-g-GO/PVA) nanocomposites was reported. Firstly, Poly(vinyl acetate)-grafted graphene oxide/Poly(vinyl acetate) nanocomposites were prepared, and then the PVA-g-GO/PVA nanocomposites could be obtained through alcoholysis reaction. X-ray photoelectron spectrometer and fourier-transform infrared spectrometer confirmed that the PVAc or PVA chains were successfully grafted to GO sheets during in-situ polymerization and alcoholysis. And the results from transmission electron microscopy, scanning electron microscopy and X-ray diffraction showed that the well compatibility and homogenous dispersion of PVA-g-GO in PVA matrix could be achieved. Differential scanning calorimetric, thermogravimetry analysis and tensile test were employed to study the thermal and mechanical properties of the PVA-g-GO/PVA nanocomposites. The results indicated that a 53% improvement of tensile strength and a 36% improvement of Young’s modulus were achieved by addition of 0.5wt% of GO sheets. And the glass transition temperature of PVA-g-GO/PVA nanocomposites was increased, and their thermal stability and crystallization degree were both decreased. Due to well dispersion of fillers and strong interfacial interactions at the filler-matrix interface, in-situ polymerization combined with chemical grafting modification was a good choice to prepare graphene/PVA nanocomposite with excellent mechanical properties.