Poly(ethylene terephthalate) composites with low-defect hydrogen-reduced graphene

The aim of this work was to prepare and characterise poly(ethylene terephthalate) (PET) composites with hydrogen-reduced graphene (HG) created using thermally expanded intercalated graphite oxide. Melt dispersion (MD) and ultrasonicated solvent-dispersion (SD) methods were contrasted. The structure, response to modulated force, temperature and permeability to gases were measured. A commercially sourced research grade graphene, sourced from Cheap Tubes,was used for comparison. PET–HG was melt dispersed using a Haake mixer with 1 %·w/wHG added. PET solutiondispersion was performed using ochlorophenolwith ultrasonication. Characterisation techniques used were: Raman spectroscopy, wide-angle X-ray scattering (WAXS) and properties were measured using: dynamic mechanical analysis (DMA), thermogravimetry (TGA), oxygen permeation (MOCON) scanning electron microscopy (SEM) and transmission electron microscopy(TEM).Low defect graphene (1 %·w/w)with Raman D/G peak ratio of 0.53 and TGA mass loss of 0.38 % O2 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40 Stress (MPa) Strain (%) 1) PET-H2-0%-MD 2) PET-H2-1%-MD 3) PET-H2-1%-SD 1 2 3 were found to increase tensile storage modulus (30 %) and loss modulus (100 %)compared with melt processed neat PET at 20 °C. Oxygen permeation increased when reduced graphene was added to PET. Melt dispersion of graphene in PET was not as effective asdispersion of graphenes using ultrasonication followed by solvent casting of films.Stress–strain showed decreased strain of ~89 % and lower hysteresis when graphene was melt dispersed into PET.