Mechanical, curing parameters and water absorption of hybrid date palm leaf-orange peel fibers reinforced unsaturated polyester composites

Abstract

In this study, polymer-hybrid natural fibers composites were prepared using unsaturated polyester resin (UPR) as the matrix and a filler using date palm leaf fiber (DPLF) and orange peel fiber (OPF). The effect of DPLF and OPF on mechanical behavior (tensile strength and elongation at break), moisture absorption, UPR gel time (tgel) and peak exothermic temperature (Tpeak) were determined. The composites of UPR reinforced with DPLF and OPF were processed by hand lay-up technique. The UPR weight fraction was maintained at 90%, and DPLF/OPF proportions varied so that the percentage of natural fiber was 10 wt%. Seven (07) composites were prepared (C1, C2, C3, C4, C5, C6 and C7) with different DPLF:OPF ratios (0:0, 1:0, 0.75:0.25, 0.5:0.5, 0.33:0.67, 0.25:0.75, 0:1) respectively in order to screen the possible interactions. DPLF were surface modified using 6% Alkali treatment, OPF were used without surface modification. Unlike DPLF, OPF showed considerable increase of UPR tgel and Tpeak which act as natural inhibitor. Tensile strength and fracture strength were also impacted negatively and positively depending on the different fiber proportions. Absorption tests showed a decrease in the composites hydrophobicity which increases significantly with higher DPLF proportions.