Design, Synthesis And Performance Study Of Carboxymethyl Cellulose-based Hydroge

Hydrogels are polymers that can absorb large amounts of liquids and maintain their stable structure.They have broad application prospects in textile,agriculture and biomedicine.Currently,petrochemical-based hydrogels occupy a major market.In order to achieve sustainable development,bio-based hydrogels have become the focus of current research.In this thesis,two kinds of hydrogels were designed and synthesized based on carboxymethyl cellulose(CMC),and their structures,properties and applications were studied..The main contents were as follows:1.A single network structure of CMC hydrogel was synthesized based on CMC.The synthetic process of CMC hydrogel was studied.When the mass ratio of CMC to crosslinking agent was 1:3.75,Na OH concentration was 0.2 mol/L,the cross-linking time was 2 h,and the reaction temperature was 60 ℃,the swelling degree of CMC hydrogel in deionized water and brine can reach 378.10 ± 42.68 g/g and 36.98 ± 1.48g/g,respectively.The hydrogel has p H responsiveness,salt sensitivity,biodegradability(complete degradation in the soil within 30 days)and excellent biocompatibility.2.Based on the single network hydrogel,second components were introduced,and CMC/cellulose composite hydrogels with semi-interpenetrating network structure were designed.In this hydrogel,the internal pore structure can be adjusted by the content of cellulose,and then the swelling and mechanical properties of the hydrogel can be controlled.3.Taking the cationic dye methylene blue(MB)as a model,the adsorption properties of the above two hydrogels were studied.Ion exchange and electrostatic attraction were the main adsorption mechanisms of hydrogels on MB.The main adsorption method is chemical adsorption.The adsorption process was a monolayer adsorption on a uniform surface,and it was a spontaneous entropy reduction exothermic process.The maximum adsorption capacity of CMC hydrogel and CMC/cellulose composite hydrogels were 275.26 ± 5.13 mg/g and 246.06 ± 7.37 mg/g,respectively.Compared with CMC hydrogel,the maximum adsorption capacity of composite hydrogels were reduced by 10.61%.After the seventh cycles of adsorption,the removal rate and adsorption capacity of CMC hydrogel can still be maintained at 70% and92.36%.The hydrogels synthesized in this study has excellent properties such as a wide range of raw materials,simple synthesis methods,biodegradability,and good biocompatibility.It has potential application prospects in the fields of textiles,agriculture and biomedical materials.