Environmentally friendly strategy to access self-healable, reprocessable and recyclable chitin, chitosan, and sodium...

Natural polysaccharides show enviable advantages for preparation of sustainable hybrid materials. However, in most cases, complex chemical modifications of natural polysaccharides are required, which not only causes changes of the inherent properties of polysaccharides, but also increases the manufacturing costs of the final materials. Therefore, it is highly desired to develop efficient and low-cost ways to access polysaccharides-containing hybrid materials. In this work, we report the environmentally friendly preparation of a new kind of polysaccharide-based materials, called polysaccharide-vitrimer hybrid materials, for the first time. The vitrimer synthesis and hybridization with polysaccharides can be achieved via a convenient one-pot method in absence of solvent and catalyst. In addition, time-consuming and labor-intensive physical/chemical modifications of natural polysaccharides are completely avoided. The resultant hybrid materials show good mechanical performance (tensile toughness is up to 13.7 MJ/m³), high thermal stability (T_d,max is up to 457 °C), fast self-healing ability (self-healing efficiency is up to 99 % within 20s at 80 °C) and excellent reprocessability and recyclability (at least three cycles). Especially, conductive polysaccharide-vitrimer hybrid materials could be readily prepared from the resultant materials, exhibiting novel applications as flexible sensors and electromagnetic shielding materials (the EMI SE is up to 24.93 dB).