Contributions of the network structure to the cure kinetics of epoxy resin systems according to the change of hardeners

The cure kinetics of epoxy resin systems was investigated according to the change of curing agents, and analyzed in respect of the network structure. An autocatalytic cure reaction can be shown in the epoxy resin systems with phenol novolac hardener regardless of the kinds of epoxy resin and the epoxy resin systems using Xylok and dicyclopentadiene type phenol resin curing agents follow nth-order kinetic mechanism. The conversion rates of novolac epoxy resins with phenyl and DCPD (dicyclopentadiene) moiety are higher than biphenyl epoxy resin (YX-4000H) and o-cresol novolac epoxy resin (EOCN-1020) systems. All kinetic parameters of each epoxy resin systems were reported in terms of generalized kinetic equation that considered diffusion term, and the network structure of each epoxy resin systems with different curing agents were analyzed using DiBenedetto equation. These kinetic data were interpreted in terms of network structure model in which a curing agent can act as a spacer and control the distances between epoxy resin units.