Nylon 6,6 electrospun nanofibrous membranes interleaved in "high performance" Carbon Fiber Reinforced Polymer (CFRP) laminates have been proposed as a means to provide a high threshold value to delamination on structural sites where composites are more prone to develop such failure. A model, highly crosslinked, thus inherently brittle, epoxy matrix was selected for its high Young's modulus and glass transition temperature exceeding 250 C. The influence of the Nylon 6,6 nanofibers on the curing behavior of the matrix and on the thermal and dynamic mechanical properties of the cured resin was investigated. These properties were related to the features of the epoxy resin and of the resin impregnated nanofibrous mat. Finally, the delamination behavior of the composite laminates interleaved with Nylon interleaves with different thicknesses was studied through Mode I delamination tests on Double Cantilever Beam (DCB) samples. The results show that the initial Mode I fracture toughness was increased up to about 50% by the presence of the thin mat interleaf. POLYM. COMPOS., 36:1303-1313, 2015
The present work investigates the fracture toughness behaviour of Single Edge Notched Bending (SENB) samples of epoxy systems subject to water uptake aging. Two epoxy systems with a significantly different Glass Transition Temperature, Tg, are in particular considered: a typical commercial non-aeronautical grade resin matrix for composite applications, reaching aTgof 90°C, and a DGEBA+DDS epoxy system achieving a Tg of 230°C.The materials have been conditioned by hydrothermal aging in a thermal bath at the temperature of 50°C. TransmissionPhotoelastic Stress Analysisis carried outon SENB samples during water aging, monitoring the presence and evolution of swelling stresses. The KIC Fracture toughness is measured and correlated with the internal stress field, with the water diffusion kinetics evaluated by gravimetric tests, and with the data from DMTA analyses. Results have highlighted significant differences in the fracture behaviour ofthe two epoxy systems
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.