The Effect of Fiber Treatment on the Water Absorption of <i>Piliostigma</i> Reinforced Epoxy

Abstract

In this paper, the water absorption behaviour of 14 days hardened composites based on Piliostigma fiber and a thermosetting matrix (Epoxy) was studied. The water absorption tests were carried out in order to study the durability of the composites. The comparative study of water absorption behaviour of composites reinforced with fiber and chemically modified in three reagents (NaOH, KMnO₄, BPO) respectively confirmed that surface treatment of the fibres influences the sorption process. The most significant decrease in hydrophilicity of Piliostigma was found in the case of Piliostigma fiber that was modified by BPO, This decrease relates to change in the chemical composition of the Piliostigma fiber, especially due to a decrease in the average degree of cellulose polymerization as well as the hemicellulose content. The chemical composition effect on the surface modification was analysed by means of Fourier Transform Infrared Spectroscopy (FTIR), The experimental spectroscopic information was compared with theoretical analysis of molecular vibrations. The result obtained from this comparison confirmed that the chemical modification of the composites was successfully carried out.

Keywords: Chemical treatment, Composite, Hydrophilicity, Natural fiber, Thermosetting, Water absorption