Study on curing kinetics of diallyl-bearing epoxy resin using sulfur as curing agent

In this paper the curing kinetics of diglycidyl ether of 4,4′-diallyl-bisphenol-A (DADGEBA) using sulfur (S) as curing agent was studied by non-isothermal and isothermal differential scanning calorimetry (DSC). The kinetic mechanism equations were determined using autocatalytic models and nth-order reaction model. DSC measurement showed that the curing process of DADGEBA/S system contains two steps because of the double exothermic peaks in DSC curve. The model data simulation results indicated that the Šesták-Berggren (SB) model had a great distinction with the experimental data. Isothermal DSC analysis showed that the curing reactions followed Kamal's autocatalytic model when the reaction temperature was below 210 °C, and when the temperature was above 210 °C the nth-order model can be used to describe the curing reaction process of the DADGEBA/S system perfectly. The two kinetic equations in the entire reaction process of DADGEBA/S system are consistent with the two-step reaction mechanisms of the same system.

► The curing reaction mechanisms of DADGEBA/S system are given in the paper.
► The SB model cannot describe the curing reaction process of DADGEBA/S system.
► Kamal's and nth-order mode can be more effective in describing the curing system.
► Autocatalytic and nth-order model are consistent with two-step reaction mechanisms.