Influence of oxazine ring content on recyclability, shape memory, and mechanical properties of bio-benzoxazine-imine hybrid resin

Abstract

Polybenzoxazine-imine hybrid resins with good thermal and mechanical properties, as well as excellent shape memory and recycling properties, were prepared from bio-based benzoxazine synthesized from vanillin and a biobased diamine derived from furylamine and benzaldehyde (V-bfa), terephthalaldehyde (TA), and Jeffamine T403. The films have good thermal, mechanical, and recycling properties, influenced by the ratio of V-bfa and TA. The higher the percentage of V-bfa, the better the thermal properties, thermal stability, and shape memory properties of the films, unfortunately, the film with 100 % V-bfa content (Btt-10) exhibited brittleness and could not be fully recovered. Surprisingly, the film with half the amount of v-bfa (Btt-11) has excellent shape memory properties, unfolding over 90° in just 12 s after folding and returning to its original shape in 20 s, moreover, the rate of shape fixation (Rf) and the rate of shape recovery (Rr) is 90.56 % and 95.56 %, respectively. Meanwhile, the thermal, mechanical, and shape memory properties of the film were also not damaged in any way even after three recycling cycles. Therefore, Btts film are very low carbon and environmentally friendly, complying with the requirement to reduce carbon emissions.