Kinetic Model for Gelation in the Diepoxide−Cyclic Anhydride Copolymerization Initiated by Tertiary Amines

The best models available in the literature to analyze gelation in the diepoxide−cyclic anhydride copolymerization are based on the mean-field approach. A kinetic model was developed to account for the nonrandom steps of the copolymerization. Two kinetic schemes were employed with one including chain transfer steps. Predicted gel-point conversions as a function of the initiator concentration were compared with experimental results obtained for a system based on diglycidyl ether of bisphenol A, methyltetrahydrophthalic anhydride, and benzyldimethylamine, as initiator. Both kinetic schemes explained the observed first-order kinetics for monomer consumption, after an induction period. However, experimental gel-point conversions could only be fitted by assuming the presence of a chain transfer step regenerating an active species.