Thermally resistant and strong shape memory bismaleimide resin with intrinsic halogen‐free and phosphorus‐free flame retardancy

Abstract Fabricating thermally resistant and strong shape memory bismaleimide resin with intrinsic halogen‐free and phosphorus‐free flame retardancy is still an interesting issue with significant challenge. Herein, a new bismaleimide (MSi) containing siloxane structure was synthesized, which was copolymerized with 2,2′‐diallylbisphenol A to develop three new resins coded as MD‐ x , x represents the molar ratio of allyl to maleimide. The composition‐structure‐performance relationship and mechanism of MD‐ x resins are systematically studied. All MD‐ x resins not only show self‐distinguish feature, but also have high glass transition temperatures (127.4–160.1°C), high impact strengths (12.09–18.77 kJ/m 2 ), high flexural strengths (91.3–97.5 MPa) and excellent shape memory properties, their shape fixation rates and shape recovery rates exceed 93% after three shape memory cycles. These attractive and competitive comprehensive performances demonstrate that the problems for halogen‐free and phosphorus‐free flame retardant shape memory polymers have been successfully solved, this is derived from the unique structure of MD‐ x resins.