EFFECT OF THE MORPHOLOGY OF THE ORGANIC FIBERS ON THE MECHANICAL-BEHAVIOR OF COMPOSITES

Scanning electron microscopy and x-ray diffraction analysis are used t o study the morphology of several aramid and polyimide fibers develope d in Russia and to determine their strain-strength characteristics. It is shown that the supermolecular structure of the fiber in large part determines the character of its interaction with the matrix and behav ior during failure of the fiber composite (FCP). In the case of aramid fibers, composite failure is accompanied by intensive fibrillation le ading to lamination on a microscopic scale and a deterioration in the service characteristics of the composite.;The stability of the investi gated polyimide fibers against fibrillation and microlamination, in co mbination with good heat resistance, makes them promising as reinforci ng materials for FCPs.