Dissolving Cylinder Zero-Order Kinetic Model for Predicting Hygrothermal Aging of Glass Fiber Bundles and Fiber-Reinforced Composites

Abstract

Glass fibers and fiber-reinforced composites degrade when exposed to water. Understanding the dissolution behaviour of glass in fiber-reinforced composites is necessary to predict the changes in physical and mechanical properties of composites. The degradation of glass fibers follows two distinct kinetic regions: short-term non-steady-state and long-term steadystate degradation. In the short-term, the degradation is complex and involves such processes as ion exchange, gel formation and dissolution. When long-term steady-state is reached, the dissolution becomes dominant and the degradation follows zero-order reaction kinetics. The purpose of this study is to present an analytical model that describes kinetics of dissolution of R-glass in fiber bundles and in fiber-reinforced composites. Effects of sizing, availability of water and accumulation of degradation products are discussed. The model is able to predict mass loss during hygrothermal aging of glass fiber bundles and fiber-reinforced composites.