Impact of Chemical Treatments on the Mechanical Properties of Olive Pomace/Epoxy Composite

Abstract

The development of a new composite material of olive stone (OS)/epoxy for economic and environmental purposes was studied. Three kinds of olive stone (OS) grain sizes of 0–1, 1–2, and 2–3.15 mm and epoxy matrix were used to fabricate composite materials. The OS were treated with two chemical solvents (hexane and dichloromethane) in order to extract residual oil present in the OS which lead to a poor adhesion filler/ matrix of the different composites. The hermogravimetric (TGA) and differential thermogravimetric (DTG) analyses confirmed the presence of residual oil in the untreated OS and less quantity of cellulose compared with treated OS. Tensile and flexural tests were conducted both for treated and untreated OS/epoxy composites. For each test type, five specimens were used according ISO-527-4 and ASTM D-790 standards, respectively. The mechanical characteristics determined showed a significant improvement for treated OS/Epoxy composites for all cases of OS grain sizes. SEM analysis confirmed a good adhesion between OS and epoxy matrix after extracting residual oil with the two solvents.