A rubberized-epoxy system for filament winding

Abstract

Tests of an epoxy material suitable as a matrix system for wet filament winding are described. The resin is a bisphenol F-based rubberized epoxy, cured with aromatic amines. First, the viscosity and pot-life of the uncured resin were measured. Then, the progress of cure for various samples at various temperatures was monitored so that an optimum cure cycle could be chosen. Mechanical tests were performed on the cured resin, and thermal properties were determined by differential scanning calorimetry, thermal mechanical analysis and thermal gravimetric analysis. Finally, the interaction of the cured resin with water was evaluated. The low viscosity (0.70 Pa s at 25°C) and sufficiently long pot-life of this material make processing easy. A cure cycle of 5 1 2 h at 60°C plus 3 h at 120°C produces a cured resin with a glass transition at 110°C. The neat material so cured has high tensile strength (128 MPa) and high modulus (4120 MPa). As has been reported in previous work, the performance of the resin in a composite was quite outstanding.