Grafting isocyanate-terminated elastomers onto the surfaces of carbon fibers: Reaction of isocyanate with acidic surface functions Original Research Article

Isocyanate functional groups can readily react with sterically accessible acidic functional groups on carbon fiber surfaces. Solvent effects on these reactions were investigated. Polar solvents such as DMF seem to favor this reaction. The grafting efficiency of isocyanate terminated-oligomers decreased with increasing molecular weight even though the total weight gain was higher when higher molecular weight oligomers were grafted. Isocyanate grafting efficiency was described by Grme = K × Mna where K = 2.7 × 103 and a = −0.82 when the solvent was DMF. Similar correlations were observed in chlorobenzene and xylene. Reactions on carbon fibers were compared to literature results on carbon black.