关键词: 木质素磺酸钠, 双网络水凝胶, 力学性能, 柔性传感

Abstract:

A kind of sodium lignosulfonate hydrogel was prepared by a simple solution blending method using sodium lignosulfonate(SL), sodium alginate(SA) and acrylic acid(AA) as precursors, where N, N'-methylenebisacrylamide(MBA) and ammonium persulfate(APS) were the cross-linking agent and initiator. This sodium lignosulfonate hydrogel was further ionically cross-linked and formed the double-network hydrogels(LSTH). Meanwhile, single-network hydrogels(LH) and acrylic hydrogels(AAH) without sodium alginate were also prepared. Then, the swelling properties, thermal stability, surface morphology, mechanical properties and strain sensing properties of the hydrogels were investigated. The results showed that when the dosage of SL was 0.2 g, the dosage of SA was 0.1 g, and the dosage of cross-linking agent was 0.02 g, the LSTH reached the highest equilibrium swelling rate of 55.31 g/g. Also, the addition of sodium lignosulfonate was beneficial to improve the thermal stability and mechanical strength of the hydrogel. When the dosage of SL was 0.2 g, the dosage of SA was 0.1 g, and the dosage of cross-linking agent was 0.05 g, the compressive strength of LSTH reached 835.53 kPa, which was 200 kPa higher than that of LH. After 90 rapid compression cycles at a high compression set of 80%, LSTH could still maintain a stable structure, good compressive strength and recoverability. The strain sensing properties showed that the hydrogel could respond quickly and be stable to external pressure and strain stimuli, indicating its good response reproducibility and stability.

Key words: sodium lignosulfonate, double network hydrogels, mechanical properties, flexible sensing