Study of the Effect of Hygrothermal Ageing on Glass/Epoxy Micro-Composites by FTIR-Imaging and Alternating DSC Techniques

Abstract

An effort was made to study the effect of hygrothermal ageing at varying intervals of time on the interphase of the fiber-reinforced polymer composites. Silane-coated glass fibers and epoxy as matrix were used to fabricate the micro-composite. Absorbance peaks of OH stretching bands were focused to study the curing mechanism of epoxy matrix and effect of hygrothermal exposure at the interphase of the micro-composite by Fourier transform infrared (FTIR) imaging. The differential scanning calorimeteric (DSC) was carried out to monitor the glass transition temperature of hygrothermally aged samples after each interval. The FTIR results shows existence of gradient in degree of curing from the interphase to the bulk matrix and with the increase in ageing time the water absorption increases at the interphase leading to improvement in the adhesion initially, as it is reflected in the results obtained with DSC analysis, i.e., increases in glass transition temperature with the ageing time was reported. Obtained improved results may be attributed to moisture induced additional ring opening polymerization of epoxide molecule and/or formation of strong hydrogen double bonds with the epoxy matrix by water molecule. Microstructural analysis was done for hygrothermally treated samples by scanning electron microscope (SEM).