EFFECTS OF HIGH-PRESSURE ON THE CRYSTALLIZATION AND MECHANICAL-PROPERTIES OF CARBON-FIBER-REINFORCED POLY(ETHER ETHER KETONE) LAMINATED COMPOSITES

The crystallization behavior of poly(ether ether ketone) (PEEK) under pressures from 0.1 to 200 MPa has been studied by using a tubular oven or hot isostatic pressing. The DSC results and SEM observations show that high pressure will enhance the formation of large spherulitic cry stals of PEEK. Three-point bending tests of the pressure-crystallized samples indicate that the modulus, critical stress and strain at crack initiation of the CCF/PEEK composite all fall with increasing pressur e. These changes in mechanical properties are considered to be associa ted with the effects of pressure on the crystallinity and spherulite s ize of PEEK.