Dissolution and Regeneration of Cellulose and Chitosan in Molten Salt Hydrate

Abstract

The energy and environmental problems caused by current fossil resources are becoming more and more serious, and the development of renewable and sustainable materials has become a research hotspot. Chitosan and cellulose, as the two most abundant biomasses in nature, have the advantages of being non-toxic, harmless, and environmentally friendly. However, due to their high crystallinity, it is difficult to dissolve in water and common organic solvents. Molten salt hydrate has been discovered as a cost-effective and non-derivative solvent system for dissolving biomass. In this paper, the dissolution and regeneration of microcrystalline cellulose and chitosan in the molten salt system to prepare gel materials is investigated using lithium bromide molten salt as an example. First dissolve cellulose and chitosan, the total mass is unchanged according to the mixing ratio of the two are divided into multiple groups, dissolved in a mass fraction of 60% lithium bromide solution at 140°C into a hydrogel, gradient regeneration in water-ethanol-tert-butanol, to produce aerogel composites, the molten salt rotary evaporation back to use. Characterization tests show that the material has uniform distribution of nanoscale pores, pore size of about 50nm, porosity of 97.53%, strain 50% range can withstand up to 0.4MPa. 6mm thickness of the sample can be insulated at 150°C for up to 2h or more, the degree of adsorption of 2500mg/L copper sulfate solution reaches 22115.4mg/g. It has excellent thermal insulation and adsorption performance and has a wide range of application prospects in environmental protection, biomedical and other fields.