Influence of Modified Epoxy Resin Systems on High Strength

Matrix modification is an effective way to improve the composite properties. In this paper, bi-functional epoxy resin was modified by the incorporation of reactive diluent, plasticizer and cycloaliphatic epoxy resin respectively and the effect of modified epoxy resin systems on high strength carbon roving reinforced composite properties Naval Ordnance Laboratory (NOL) ring tensile strength and Interlaminar Shear Strength (ILSS) were studied. Modified epoxy resin system with reactive diluent exhibited good toughness and low viscosity with better penetration and wettability to high strength carbon rovings leading to effective translation of fiber strength in the final composite. Compatibility of the modified epoxy resin with T-700 carbon fiber was ensured by Impregnated tow, NOL ring tensile and ILSS tests. Instrumental methods of analysis using Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR) and Energy Dispersive Analysis of X-rays (EDAX) were employed in analyzing the interfacial behavior. Failure modes indicated the role of matrix in effective load transfer in filament wound ring specimens. Reactive diluent modified epoxy resin system improved considerably the NOL ring tensile strength and ILSS properties.