Progress in the Development of Elastomeric Matrix Composites

The elastomeric matrix composites are comprised of high performance fibers such as glass, carbon. Kevlar and a low modulus. high elongation matrix material. Such composites maintain very high strength, while allowing much greater flexibility than conventional rigid matrix composites. Initial evaluation of composites fabricated with commercially available urethanes revealed performance limitations due to temperature sensitivity. high hysteresis, limited modulus range and difficult processing characteristics. A new MXU Series of elastomers have been developed specifically for composite applications. These materials showed dramatic reductions in hysteresis and temperature sensitivity and a better retention of properties at elevated temperatures. Initial dynamic testing has been performed on drive shafts fabricated using these new matrix materials. In dynamic bendingiconstant torque tests, the MXU composites showed an increase in fatigue life of more than 500 times the previous material. A rotating beam fatigue test at an equivalent bending strain of .86% and 2200 rpm completed 150 million cycles with no damage to the test samples. These performance improvements demonstrate the potential for practical application of elastomeric matrix composites.