Acid Resistance of Glass Fibre Composites with Different Layup Sequencing Part II: Degradation Studies

Abstract

The degradative effects of sulphuric acid on glass fibre composites with different layup sequencing were studied by monitoring the changes in the Inter Laminar Shear Strength (ILSS) using short beam shear specimens. The composite specimens used for the diffusion studies in Part I were chosen for the degradation studies. The results of the studies indicated that isopthalic polyester resin composites retained maximum percentage of Inter Laminar Shear Strength, while those of the General Purpose Resin showed higher degradation. The degradation increased as the concentration of the sulphuric acid was increased, indicating that degradation was a dominant phenomenon at higher concentrations. The weave compactness of woven roving type glass reinforcement which formed the face skin in the case of composites of sequential layup C accounted for better performance of these composites in Sulphuric acid environment, while the presence of a loosely bonded chopped strand mat as the skin in composites of sequential layup A caused higher degradation.