Comparative Study of The Kinetic Behaviors And Properties Of Aromatic And Aliphatic Bismaleimides

Abstract

In this paper, three aromatic bismaleimides (BMI-70, BMI-DE and BMI-80) and two aliphatic bismaleimides (BMI-DDA and BMI-C36) were synthesized. The structures were characterized using NMR spectra and Fourier infrared spectroscopy (FT-IR). The curing kinetics were examined through non-isothermal DSC. The results indicate that the aliphatic bismaleimides exhibit lower apparent activation energies, with BMI-DDA displaying an average activation energy of 105.5 kJ·mol-1. The thermal and dielectric properties of the poly(bismaleimide) were investigated using thermogravimetric analysis (TGA), dynamic thermo-mechanical analysis (DMA), and an impedance analyzer. The results showed that the aromatic polybismaleimides possessed better thermal stability, among which, the 5% thermal decomposition temperature (Td,5) of P(BMI-70) was 513.5 ℃, and the residual carbon rate at 800 ℃ was 44.6%. The aliphatic bismaleimide exhibited better dielectric properties, and the dielectric constant of P(BMI-C36) is 2.558 @ 10 MHz. In additional, water absorption was studied and their saturated water absorption was less than 4%.

Keywords: Bismaleimide, Aliphatic, Aromatic, curing kinetics, thermal properties, Dielectric properties