Effects of silane treated fiber on impact properties of hydrothermal aged glass fabric/epoxy laminates

This study dealt with the effects of the silane treatment on the mechanical properties of glass fabric/epoxy laminates immersed in hot distilled water. Two kinds of the silane coupling agents (amino silane and methacryl silane) were used, and these were different in the chemical reactivity with epoxy resin. The specimens were immersed in hot water, and the weight change measurement, the static tensile test and the impact flexural test were performed. The weight loss occurred for the methacryl treated laminate, and as a result, the debonding at the fiber/matrix interface and the water penetration into the interface occurred. The degradation of the interface affected the tensile and the impact properties, and it induced the greater modulus and strength reduction. The silane treatment affected the fracture behavior under both the static tensile loading and the impact flexural loading. The long and large scale cracks propagated inside the fiber bundles in the amino treated laminate, while the multiple cracks occurred inside the fiber bundles in the methacryl treated laminate. The fracture mode changed as a result of the debondings inside the fiber bundles due to water immersion in the methacryl treated laminate. The difference in the fracture behavior affected the tensile strength reduction and the change of the impact energy absorption due to the water immersion.