Nonisothermal reaction kinetics of DGEBA with four-armed starlike polyamine with benzene core (MXBDP) as novel curing agent

A four-armed starlike polyamine with a benzene nucleus (MXBDP) was prepared, characterized, and employed as the novel curing agent for epoxy resin of bisphenol A (DGEBA). Nonisothermal reaction kinetics of DGEBA/MXBDP was systematically investigated using a differential scanning calorimeter (DSC) in terms of a model-fitting Málek approach and a model-free advanced isoconversional method of Vyazovkin (AICM). A two-parameter autocatalytic model of Šesták–Berggren (SB(m, n) model) was substantiated to be able to well describe the nonisothermal reaction rate of DGEBA/MXBDP. In addition, the correlation between effective activation energy Eα upon fractional conversion α was determined with the AICM. The result showed Eα dropped quickly at the initial stage of the reaction up to α ≈ 10%, then showed a relative constant value of ≈57 kJ/mol for α ≈ 10–35%, and finally decreased again from ≈57 to ≈45 kJ/mol until the completion, which implicates quite complex mechanisms of the reaction.