Study On The Preparation And Performance Of Chitosan Conductive Double Network Hydrogel

In this paper,two kinds of conductive double network（DN）hydrogels based on chitosan were successfully prepared by using natural polymer chitosan as the carrier.The main work is as follows:First,the DN hydrogel was synthesized by UV-initiated polymerization using chitosan（CS）as the first network and poly（acrylic acid-sodium p-styrene sulfonate）as the second network.Then the chain entanglement is induced by immersing in a 2 M aqueous sodium chloride solution.The chitosan/poly（acrylic acid-sodium p-styrene sulfonate）/sodium chloride（CS/P（AA-co-SS）/Na Cl）DN hydrogel with high conductivity and excellent mechanical properties was successfully prepared by the one-pot method.The elongation at break of CS/P（AA-co-SS）/Na Cl DN hydrogel is 620%,the tensile strength is 533 k Pa,and the electrical conductivity is 4.13 S/m.It has excellent resilience and fatigue resistance during the continuous stretching and compression.The wearable sensor prepared from the hydrogel has high sensitivity（at 100% strain,specification factor = 2.4）and repeatability,and it can accurately detect various movements of the human body after being attached to the human body.In addition,due to the introduction of sodium p-styrene sulfonate and sodium chloride,the hydrogel has excellent frost resistance even at-20 °C and still exhibits excellent electrical conductivity and mechanical properties.Second the DN hydrogel was synthesized by using chitosan as the first network and poly（acrylic-acrylamide）as the second network.Sodium chloride（Na Cl）and glycerol（GI）were introduced into the solution,then chitosan / poly（acrylic acid-acrylamide）/glycerol/ sodium chloride（CS/P（AA-co-AM）/GI/Na Cl）DN hydrogel was prepared by ultraviolet light.The elongation at break of the CS/P（AA-co-AM）/GI/Na Cl DN hydrogel is 590%,the tensile strength is 400 k Pa,and the electrical conductivity is 0.45 S/m.It has excellent resilience and fatigue resistance during the continuous stretching and compression.In addition,due to the introduction of glycerin and sodium chloride,the hydrogel has excellent frost resistance and dry resistance,and it still exhibits excellent electrical conductivity and mechanical properties even at-20 °C.When it is placed at room temperature for 30 days under ventilated conditions,the water loss rate of the hydrogel is only 13.9%.