Mechanical characterization of carbon fiber reinforced phenolic resol and epoxy condensate plastic

A matrix resin for carbon fiber reinforced composite was developed that con sisted of resol type phenolic and difunctional epoxy resin (PR-EP) condensa te or adduct. Carbon fiber reinforced composite with fiber volume fraction of 0.6 was prepared, with PR-EP matrix containing 0, 50, 100, 150, and 175 parts of epoxy resin per hundred parts of phenolic resin (php), especially a synthesized resol type. One-shot and prepreg techniques have been adopted and the study of loss of volatiles has indicated the superiority in terms of favorable processability of prepreg technique over the other. FTIR spect roscopic analysis confirmed the PR-EP adduct formation at the prepreg prepa ration stage. The improvement in properties such as tensile strength and el ongation at break was observed in resin matrices with epoxy and phenolic re sin; however, the flexural strength and modulus remained more or less unalt ered. The prepreg technique of composite preparation has resulted in substa ntial improvement in mechanical properties and the same was attributed to t he formation of PR-EP adduct and low volatiles during cure. Composites of c arbon fiber reinforced PR-EP matrix developed here are likely to meet the r equirement of aerospace structures in view of the realization of a wide spe ctrum of properties.