An Individualized Core–Shell Architecture Derived from Covalent Triazine Frameworks: Toward Enhancing the Flame Retardancy, Smoke Release Suppression, and Toughness of Bismaleimide Resin

Although the bismaleimide (BMI) resin is a star material in industries, its further applications have been plagued by the serious brittleness and fire hazard for a long time. Hence, a core–shell architecture (MPPM) derived from covalent triazine frameworks was designed to overcome the shortcomings. Excitedly, compared to those of neat BMI, the resultant BMI-2 with only 1 wt % MPPM was capable of achieving 23.4%, 48.6%, and 39.7% decrements on the peak of heat release rate, total heat release, and total smoke release, respectively, exhibiting unprecedented flame-retardant effects under a low addition of flame retardants. Besides, the impact strength of BMI-2 was enhanced by 62.7% with a close tensile strength and storage modulus to those of neat BMI, implying that the toughness of BMI was improved successfully without sacrificing its rigidity. This work provided a unique clue for designing efficient multifunctional modifiers and promoted the development of advanced BMI.