Catalytic degradation of a carbon fibre reinforced epoxy resin with an acetone/water solvent

The degradation of a carbon fibre reinforced RTM6 epoxy resin with an acetone/water mixture and range of potential catalysts has been investigated. NaOH, KOH and ZnCl2 were supplied at a concentration of 0.01 to 0.4 M with the data obtained showing that the alkaline salts do not enhance the reaction. ZnCl2, however, is able to effectively strip the resin from the fibre surface with a resin removal yield in excess of 94% observed when processed at 290°C for 1.5 h or at 300°C for 45 min. Fibre tows recovered appeared clean, were perfectly separated and retained their weave architecture. The research presented demonstrates a significant improvement on earlier work by reducing reaction time by 25% and temperature by 30°C. FTIR spectra of the organic liquid fraction suggested that chloride ions cleave the C=N bond and hence accelerate the rate of reaction. Aside from this, spectra obtained from different catalyst systems were similar with all mixtures containing peaks characteristic of O-H, N-H, C=S and R-SO2-R bonds. As these represent a mixture of recoverable, potentially high value compounds, the developed technique could offer an advantage over pyrolysis processes.