Curing reaction of o-cresol-formaldehyde epoxy/LC epoxy(p-PEPB)/anhydride(MeTHPA)

The curing kinetics of a bi-component system about o-cresol-formaldehyde epoxy resin (o-CFER) modified by liquid crystalline p-phenylene di[4-(2,3-epoxypropyl) benzoate] (p-PEPB), with 3-methyl-tetrahydrophthalic anhydride (MeTHPA) as a curing agent, were studied by non-isothermal differential scanning calorimetry (DSC) method. The relationship between apparent activation energy E(a) and the conversion alpha was obtained by the isoconversional method of Ozawa. The reaction molecular mechanism was proposed. The results show that the values of E(a) in the initial stage are higher than other time, and E(a) tend to decrease slightly with the reaction processing. There is a phase separation in the cure process with LC phase formation. These curing reactions can be described by the Sestak-Berggren (S-B) equation, the kinetic equation of cure reaction as follows: d alpha/dt = A exp(-E(a)/RT)alpha(m)(1-a)(n).