Synthesis and properties of novel bismaleimide containing allyl group and twisted structure

Abstract

In this work, a bismaleimide (ABFBMI) monomer with allyl group, cardo, and oxazine structures was synthesized for the first time. The monomer was characterized with the help of Fourier transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance (1H NMR), and nuclear magnetic resonance carbon spectroscopy (13C NMR). The curing kinetics and polymerization process were studied using differential scanning calorimetry (DSC) and in-situ FTIR. Thermogravimetry (TGA), DSC and scanning electron microscope (SEM) were used to examine the thermal properties and fracture morphology. The ABFBMI was found to have polymerized through self-catalytic curing. Thermosetting materials (poly(ABFBMI)) underwent structural transformation at high temperatures to form polybenzoxazole resin (cPBO-ABFBMI). Poly(ABFBMI) and cPBO-ABFBMI both have excellent thermal stability. The flexible allyl group side chains enhance the toughness of poly(ABFBMI). The stable twisted non-coplanar and allyl group structure are responsible for the excellent solubility and melt processability of ABFBMI.