Properties of novel polyimides containing bismaleimide and cyclic phosphine oxide

New polyimide polymers with phosphorus in the main chain were obtained from synthesized bismaleimide (EPBMI) cured with three types of curing agents: 4,4′-bismaleimidodiphenylmethane (BDM), 4,4′-bismaleimidodiphenyl- ether (BDE), and 4,4′-bismaleimidodiphenylsulfone (BDS). In addition, the compositions of the new polymers synthesized with these three curing agents (BDM, BDE, and BDS) were used to compare the curing reactivity and thermal properties of EPBMI to conventional bismaleimide (EBMI). The reactivities were measured by differential scanning calorimetry. Thermogravimetric analysis revealed the polymers, obtained through the curing reactions between EPBMI and the three curing agents mentioned also demonstrated excellent thermal properties and a high char yield compared to the EPBMI homopolymer.