MULTIPHASE MATRIX POLYMERS FOR CARBON-FIBER COMPOSITES

The effect of different matrix polymers on the impact resistance Of carbon-fiber-reinforced polymers is reviewed. These polymers include unmodified, tetrafunctional epoxies, elastomer-modified epoxies, epoxies plasticized with low levels of thermoplastics, thermoplastics, and thermoplastic-modified thermosets (TMT). The results of some recent work on the impact resistance of TMT matrix composites is discussed. The TMTs were of two types: thermoplastic particles interlayered between plies and co-continuous interpenetrating network polymers. Suppression of interlaminar longitudinal cracking was found to correlate with improved resistance to impact damage.