Curing Kinetics and Dielectric Properties of Anhydride Cured Epoxy Resin With Different Accelerator Contents

Abstract

The addition of accelerator reduces the curing reaction temperature, changes the curing reaction process, and affects the morphology of the crosslinking structure, which would lead to the difference in the dielectric properties of the epoxy resin. In this study, the curing behaviors and dielectric properties of diglycidyl ether of bisphenol A (DGEBA)/methyl hexahydrophthalic anhydride (MHHPA) were investigated with respect to the contents of the curing accelerator, Tris-(dimethylaminomethyl) phenol (DMP-30). The curing behavior of epoxy resin was studied by differential scanning calorimetry (DSC), and it was found that the system conforms to the Sestak–Berggren kinetic model [SB ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${m},{n}{)}$ </tex-math></inline-formula> ]. The accelerator content has a saturation effect on the dielectric properties of the epoxy resin curing sample, and excessive content can lead to the increase of dielectric constant and loss and decrease of breakdown strength. The cured sample with 0.5% accelerator addition has the best dielectric properties and the highest breakdown strength. The analysis concludes that the optimum accelerator content allows for a more rational curing crosslinking network.