Curing Kinetics and Rheology of Diglycidyiether of Bisphenol-A Modified by Poly(ethylene glycol) Flexible Chains

Abstract

The curing reaction of the system bisphenol-A glycidol ether epoxy resin modified by poly (ethylene glycol) (PEO) and flexible amine (D-230) as curing agent has been studied by means of differential scanning calorimetry (DSC) and thermal scanning rheometry. The curing kinetic parameters have been calculated from the non-thermal DSC curve. The kinetic analysis suggests that the two-parameter autocatalytic model is more appropriate to describe the kinetics of the curing reaction of the system. Increasing the PU content leads to an increase in the heat of curing and has a little effect on the kinetic parameters apparent activation energy (Ea), pre-exponential factor (A), and order of the reaction (m and n). The rheological properties were measured by isothermal curing evolution. Introduction of PEO flexible chains delayed the polymerization. It has been confirmed that the introduction of PEO chains in the structure of the epoxy resin increases the mobility of the molecular segment of the epoxy networks and results in the decrease in glass transition temperature.