Preparation and properties of T300 carbon fiber-reinforced thermoplastic polyimide composites

In this study, a series of T300 carbon fiber-reinforced polyimide (CFRPI) composites were prepared by laminating premolding polyimide (PI) films with unidirectional carbon fiber (CF) layers. On the basis of PI systems design, the effect of CF volume fraction, processing conditions, and PI molecular structure on the properties of CFRPI composites was studied in detail. In addition, two kinds of nano-particles, including carbon nano-tube (CNT) and SiO2 were filled into the premolding PI films with different concentrations. And the effect of nano-particles on the properties of CFRPI composites was also investigated. The surface characteristic of T300 CF was measured by X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR). The properties of premolding PI film and CFRPI composites were measured by dynamic mechanical analysis (DMTA), SANS testing machine, scanning electron microscopy (SEM), and so forth. These experimental results showed that the properties of CFRPI composites were mainly affected by the premolding PI film and molding condition. The change of CF volume fraction from 55% to 65% took little effect on the mechanical properties of CFRPI composites. In addition, the incorporation of nano-particle SiO2 could further improve the properties of CFRPI composites, but CNT hardly improved the properties of CFRPI composites. (c) 2006 Wiley Periodicals, Inc.