Chemical modification of waste oil fly ash for improved mechanical and thermal properties of low density polyethylene composites

In this paper, oil fly ash (OFA), a by-product generated by the combustion of oil in power plants, was used as a filler for the preparation of low density polyethylene (LDPE) composite. Four different loadings of filler in the range 1-10%wt were used. Both mechanical and thermal properties were studied using tensile measurements and Differential Scanning Calorimetery. The effect of surface modification of OFA by functionalization with COOH group and the effect of polyethylene-grafted-maleic anhydride as a compatibilizer were also examined. Improvement in Young's modulus and yield strength of OFA was obtained in the range 1-2% as a result of chemical modification and mainly in the range 5-10%w due to compatiblization. However, a decrease in toughness and elongation at break was also observed. In general, functionalization and compatiblization improved small strain mechanical properties and failed to do the same for large strain properties of composites. No considerable effect for fly ash on melting point, on-set temperature and crystallization peaks was observed. Coupling of functionalization and compatiblization can enhance modulus and tensile strength mechanical properties of composites of LDPE and waste ash.