PREPARATION AND CHARACTERIZATION OF GO AND RGO-FILLED LDPE COMPOSITES

This study aims to prepare GO and RGOfilled LDPE composites to investigate their barrier properties in hopes to use RGO-filled LDPE as an economical and efficient liner for oil and gas pipelines to prevent corrosion. Graphene oxide (GO) was synthesized from natural graphite flakes by using an improved Hummers method and reduced into reduced graphene oxide (RGO) by chemical reduction using ascorbic acid. FTIR analysis revealed the presence of oxygenated functional groups in the GO and the removal of oxygenated functional groups in the RGO. RGO showed a reduction in hydroxyl groups. LDPE composites containing 0.5 wt% and 1 wt% of GO and RGO were developed through melt mixing. TGA results showed that there was an increase in thermal stability with the addition of filler and that the 1 wt% RGO/LDPE composite had the greatest thermal stability. The mechanical strengths of the composites improved with GO and RGO filler addition. The RGO/LDPE composites exhibited increased tensile strength and Young modulus as well as comparable elongation at break as compared to 100 wt% LDPE and GO/LDPE composites. Morphological analysis through SEM confirmed the presence of agglomeration for both 0.5 wt% and 1 wt% GO/LDPE composites, while both 0.5 wt% and 1 wt% RGO/LDPE composites showed smoother structural morphology with no agglomeration. The RGO/LDPE composites had the best moisture and solvent resistance as compared to the 100 wt% LDPE and GO/LDPE composites. A corrosion test conducted proved that metal plates coated with the 1 wt% RGO/LDPE composite exhibited the best corrosion resistance ability with a corrosion rate of 0%. Thus, the RGO/LDPE composites at 1 wt% RGO loading is the most optimum filler and composition to be used as coating material for carbon steel metal pipelines.