Polybismaleimides (BMI)

Developed since the 1960s, polyimide resins represent a fast-growing family of specialty polymers. Their physico-chemical properties, linked to formulations based on aromatic monomers, make them materials of choice for applications requiring high thermal stability during prolonged exposure to high temperatures, or requiring good dielectric properties. Within the polyimide family, two main classes can be distinguished:

• linear thermoplastic resins, generally obtained by polycondensation of aromatic diamines with aromatic dianhydrides. This class is described in the "Linear polyimides (PI)" dossier [AM 3 398] [1] ;

• thermosetting resins, obtained from polyimide oligomers whose reactive ends can crosslink under the action of temperature. These include polybismaleimide resins, whose main advantage lies in their ease of processing compared with linear polyimides.

In this dossier, we focus exclusively on polybismaleimide thermosetting resins, covering their preparation, characteristic properties, processing and fields of application.