Change of the physicomechanical properties of fibrous polymer composites exposed to moisture and low temperatures

We investigated the cyclic effect of water and the simultaneous effect of water and low temperatures on the properties of fibrous polymer composites. Methods of sorption, thermogravimetry, and mechanical tensile, bending, and interfacial shear tests were used. It was established that for carbon plastic and organite the most aggressive external factor is water, and the vulnerable link is the matrix and the reinforcing fiber. For boron plastic the aggressive factors are water and the joint effect of water and low temperatures; the vulnerable link is the fiber—matrix interface.Paper to be presented at the Ninth International Conference on the Mechanics of Composite Materials (Riga, October, 1995).Translated from Mekhanika Kompozitnykh Materialov, Vol. 31, No. 4, pp. 501–508, July–August, 1995.