High–strength, solvent–resistant carboxymethyl chitosan composite rubber based on dual covalent crosslinking network and hydrogen bond network for multi–functional sensing

In order to prepare natural polymer composite rubber with excellent mechanical properties, solvent resistance and electrical conductivity, and to apply it to multifunctional sensing. In this study, an environmentally friendly and effective strategy was employed to solve these problems. Carboxymethyl chitosan composite rubber was prepared by introducing the dual covalent crosslinking network into carboxy nitrile butadiene rubber via amide and radical reactions, followed by blending with carboxymethyl chitosan to introduce a hydrogen bonding network. The tensile strength of the prepared composite rubber was increased by 45 times, the crosslink density was increased by 405 times, the mechanical properties and solvent resistance were significantly improved, and the electrical conductivity was also obtained. Based on these excellent properties, carboxymethyl chitosan composite rubber can be used in strain sensors to detect human movement, and realize information encryption; it can also be used in humidity sensors to detect human respiration, environmental humidity and industrial pipeline safety. The nature polymer composite rubber prepared in this work will have great potential for application in flexible electronic devices.