A Tailorable Series of Elastomeric-To-Rigid, Selfhealable, Shape Memory Bismaleimide

In recent years, there has been rapid development in the field of shape memory materials with active deformation performance. However, bismaleimide, a widely used thermosetting material in aerospace, has been largely overlooked in shape memory applications. This work presents the synthesis of a molecule containing an alkene bond adjacent to an oxygen atom. Through molecular design, a one-time reaction between this specialized molecule and the bismaleimide molecule is successfully achieved, facilitated by the steric hindrance effect. Therefore, a new series of shape memory bismaleimide materials are obtained. By introducing a diamine to adjust the chain length, the properties of material are further improved, resulting in increasing static modulus by 506 times. The synthesized materials exhibit a broad glass transition temperature (Tg) range exceeding 153 degrees C, remarkable stiffness tunability. Notably, in the synthesis process of this materials series, the disulfide bonds are introduced, which facilitates the realization of self-healing and reprocessable functionalities in the resulting thermosetting materials. This significant advancement lays a solid foundation for the future recycling and reuse of aircraft, satellites, and other equipment, offering promising prospects for enhancing sustainability and efficiency within the aerospace industry. The study proposes a thermosetting shape memory resin system, with elatomeric-to-rigid performance, self-healing, and reprocess functionality. Through the design of steric hindrance, shape memory performance (fixing ratio 99.4%) is achieved. By introducing diamine molecules to adjust the crosslink density, 506-fold static modulus changes are achieved. Disulfide bonds help to realize self-healing and reprocessable functionalities, with healing efficiency of 93.2%.image