CORROSION OF E-GLASS FIBERS IN ACIDIC ENVIRONMENTS

This study is concerned with the corrosion behavior of E-glass fibers exposed to oxalic, hydrochloric, nitric and sulfuric acids. The result s reveal that acid corrosion of E-glass fibers is primarily attributed to calcium and aluminum ion depletion. The leachability of these meta llic ions is not only determined by the hydrogen ion concentration but also strongly affected by the anions in the acids. The formation of i nsoluble salts or complex ions between the anions in oxalic and sulfur ic acids and calcium and aluminum ions leached out from the glass acce lerates fiber corrosion considerably. Furthermore, acid corrosion may generate axial or spiral cracks on the fiber surface, depending on aci d type and concentration. In this study, an ion-depletion-depth model is proposed to explain the mechanisms of fiber surface cracking the ax ial crack formation is most likely associated with a larger ion-deplet ion depth than the spiral crack formation. (C) 1997 Elsevier Science L imited.