Kinetic reaction analysis of an anhydride-cured thermoplastic epoxy: PGE/NMA/BDMA

A comprehensive reaction analysis of a linear epoxy resin cured with an anhydride was performed to evaluate the reaction rate expressions. Monomers included phenyl glycidyl ether and methyl-5-norbornene-2,3-dicarboxylic anhydride or nadic methyl anhydride; the catalyst was N,N-dimethylbenzylamine; the initiator was n-propanol. Emphasis was initially placed on the molar dynamics of monomeric and oligomeric molecules. Molecular fractionations were achieved using reversed phase, high performance liquid chromatography. Chemical reaction rate constants were examined as a function of degree of polymerization. For the chain-initiated polymerization, the initiation rate constant was observed to be approximately 3 times greater than the propagation constant associated with oligomeric molecules. Both Poisson and Gold distributions were used to fit data. Examinations of polymeric fractions obtained by gel permeation chromatography in conjunction with a multiangle laser light scattering photometer revealed a minor side reaction that broadened the polydispersity index and resulted in the reduction of the cumulative, molar concentration of molecules as a function of conversion.