Effect of toughness modification on viscoelastic properties of epoxy matrix composites

This study investigated the effect of toughness modification on viscoelastic behavior of neat resin epoxy matrices and their corresponding fiber composites. The results suggest that the activation energy-vs.-temperature relationships and consequently the viscoelastic responses below the glass transition temperatures are similar between the basic and modified resin systems if the difference in the respective glass transition temperatures are taken into account. In addition, similar experiments were performed on the fiber-reinforced laminate samples. Quantitatively, the contribution of fiber to the viscoelastic behavior of the laminates could be properly accounted for by applying micromechanic analysis.