Effect of coupling agents on the olive pomace-filled polypropylene composite

Abstract

Abstract The effect of the olive pomace flour (OPF) addition on the mechanical, water uptake, morphological, and thermal properties of polypropylene (PP) with and without the use of two coupling agents was investigated. A higher percentage of a coupling agent yielded a greater impact strength of 141 J/m. Tensile and flexural properties of the OPF/PP composite were improved with the two coupling agents. The addition of OPF to pure PP had reduced these properties, thus proving the utility of the coupling agents. While the addition of the OPF to PP increased the water uptake property by 1.36%, the subsequent addition of a coupling agent decreased it to 0.78%. For the neat PP, the enthalpy of melting (∆H m = 123 J/g), the enthalpy of crystallization (∆H c = 133 J/g), and the percent of crystallinity (X c = 59%) values showed a declining trend down to 91, 103 J/g, and 44%, respectively, when the filler and coupling agents added to the composite. The results of this study demonstrated that the OPF could be used as a viable reinforcement for the PP, providing good mechanical and morphological properties, as long as an appropriate coupling agent proportion is added to the composite.