Effect of surface treatment on the hydrolytic stability of E-glass fiber bundle tensile strength

The tensile strength of glass fiber bundles is highly dependent on flaw nucleation and growth from contact abrasion and hydrolytic degradation. The effect of fiber surface treatment on the hydrolytic stability of tensile strength is investigated for E-glass fiber bundles with four commercial sizings. Acoustic emission (AE) generated by individual fiber fracture events provides a means to determine a Weibull distribution of fiber strengths. Fiber bundles with starch, starch and silane, starch and wax, and epoxy surface treatments are tested following exposure to 10%, 40%, 80% relative humidity and immersion in water. The tensile break strength, number of breaks at peak load, and Weibull moduli of the glass fiber bundles are strongly dependent on the humidity level. The different surface treatments considered in this investigation strongly alter the absolute mechanical properties and the effect of exposure to humidity.