Characterization of Epoxy-hybrid nano-particle Resins for ambient cure VARTM Processes

Abstract

This thesis presents the mechanical characterization of fire resistant epoxy-hybrid resin systems suitable for ambient cure VARTM processes. Several new epoxy-hybrid nano-particle resins were developed and tested for use in large scale composite structures. Based on the viscosity, Tg, and cure time requirements twelve of these resins systems were pre-selected for mechanical testing. Neat resin castings were tested in tension to determine the elastic modulus, tensile strength and maximum elongation. From these results, six of the resin systems were further cast in unidirectional glass fiber laminates. Transverse tension and short beam shear testing was performed on all laminates to determine the mechanical properties of the glass/epoxy systems. Two of the epoxy-hybrid resin systems showed promising behaviors, having a higher transverse modulus and ultimate strength than the original benchmark vinyl-ester resin. Additionally, fiber Bragg grating sensors were embedded in one benchmark vinyl-ester laminate and one epoxy-hybrid laminate during the cure cycle. Taking advantage of both the extrinsic and intrinsic properties of these sensors, residual strains, temperature changes, and degree of cure of the resin were monitored. In addition to having a higher modulus of elasticity and ultimate strength, these new epoxy-hybrid nano-particle resin laminates showed minimal temperature increases during cure and smaller residual strains than the comparable vinyl-ester resin laminates.