Preparation And Properties Of Cellulose/montmorillonite High-strength Composite Hydrogel

Cellulose is a kind of green,environment friendly and renewable biomass resource that widely distributed in nature.As a kind of high molecular polymer material,the cellulose hydrogel prepared by cellulose exhibits the advantages of good biocompatibility,rapid reaction and easy recycling,which makes it show a wide range of application in the fields of pollutant adsorption and so on.In this study,cellulose-based hydrogel was used as a template.Montmorillonite and polymer PAM were introduced into the hydrogel structure to successfully construct cellulose-based composite hydrogels,thereby solving the problems of poor adsorption performance and mechanical strength of the composite hydrogels.And the possibility of applying them for dye adsorption was explored.This paper mainly conducts research from the following three aspects:(1)Cellulose solution was prepared by Na OH/Urea solution system.After adding montmorillonite,the cellulose composite hydrogels were successfully prepared by a chemical crosslinking method.The effect of montmorillonite as the dispersed phase on the composite hydrogel performance was studied.The results display that montmorillonite can be well dispersed in cellulose hydrogel.And with the content of MMT in the hydrogel increases,the mechanical strength of the hydrogel gradually increases.When the amount of MMT reaches80%,the maximum compressive strength of the as-prepared hydrogel CHM-80% reached128.17 k Pa.At the same time,the adsorption performance of CHM-80% has also been significantly improved,the theoretical maximum adsorption capacity of methylene blue can reach 88.81 mg/g.Besides,CHMs also show good recycling performance.(2)The montmorillonite was modified with two silane coupling agents,APTES and VTES.After that,the two kinds of modified montmorillonites were dispersed into the cellulose solution,and two kinds of cellulose/modified montmorillonite composite hydrogels(CHAM and CHVM)were prepared by using MBA as a crosslinking agent.The results show that montmorillonite has been successfully modified,and the interlayer spacing has increased.Compared with CHM-80%,the composite hydrogel containing two kinds of modified MMT showed a significant increase in compressive strength.The compressive strength of CHAM and CHVM reached137.86 KPa and 150.62 KPa,respectively.And their theoretical maximum adsorption capacity for MB reached 148.17 mg/g and 168.35 mg/g,respectively.(3)On the research basis of the cellulose/modified montmorillonite composite hydrogel CHVM,a polyacrylamide was synthesized on the CHVM framework by IPN method to construct a kind of high-strength composite hydrogel.The results exhibit that with the increase of acrylamide monomer concentration in the solution,the adsorption capacity of methylene blue was decreased due to the over-crosslinking network structure.However,the maximum compressive strength and fracture strain of the as-prepared composite hydrogel increase gradually,reaching the maximum of 2.66 MPa and 67.51%.Indicating that the mechanical strength and toughness of the composite hydrogels have been significantly improved,which broadens the application of the as-prepared composite hydrogel in other high-strength fields.