Preparation And Performance Study Of Cellulose Urethane Regenerated Membrane By Ionic Liquid Method

Since the 21st century,green environmental protection has become the main theme of world development,and people's demand for renewable and sustainable materials is increasing.As the most abundant and renewable organic green polymer material in nature,cellulose is widely used in people's production and life.However,the cellulose molecule has abundant hydrogen bonds,which makes it difficult to dissolve in common solvents,the traditional cellulose dissolving system such as CS₂-Na OH is not only seriously polluted,but also has limited solubility for cellulose,which can no longer adapt to the trend of the times.In this work,cellulose carbamate was prepared from wood pulp cellulose,urea and DMAc.Cellulose carbamate was dissolved and regenerated with AMIMCI as solvent to prepare regenerated cellulose membrane.The rheological properties of the cellulose carbamate solution and the structural properties of the regenerated cellulose membrane were also studied.The dissolution experiment show that the solubility of cellulose carbamate reached25%.The static rheological test results show that CC solution is a typical non-Newtonian fluid;as the temperature increases,the non-Newtonian index of the solution increases,and the structural viscosity index decreases;as the concentration of the solution increases,the structural viscosity index and viscous flow activation energy of the solution increase,while the non-Newtonian index decreases;the dynamic rheological tests show that after reducing the CC content and increasing temperature,the solution was dominated by viscosity,on the contrary,by elasticity.Through Fourier Infrared Transform Spectroscopy(FTIR),X-ray Diffraction Spectroscopy(XRD),Thermogravimetry(TG)and Scanning Electron Microscope(SEM)tests and analysis,the results show that the amino group was successfully introduced into cellulose,Cellulose carbamate and regenerated cellulose membrane are typical cellulose?crystal form,they both maintain good thermal stability and crystallinity,the regenerated cellulose membrane has a dense surface and section.Through orthogonal experiment and range analysis,the factors affecting the structure and performance of the cellulose membrane were discussed,and the dye retention capacity of the regenerated cellulose membrane and the antifouling ability of oil-water separation were tested,the results show that when the mass fraction of cellulose carbamate is 9%,the dissolution temperature is 110°C,the coagulation bath is water,the tensile strength of the wet membrane is 7.6MPa,the elongation at break is 98.5%,and the tensile strength of the dry membrane is 122.6MPa,the elongation at break is 20.8%,the porosity is 93.68%,and the light transmittance is 94.08%;the rejection rates of regenerated cellulose membrane for methyl blue,Congo red,and methyl orange are 100%,99.8%,and 42.3%,respectively;the oil-water separation rate of regenerated cellulose membrane reached100%,after repeated recycling,the recovery rate of pure water flux has reached 100%,showing extremely strong antifouling performance.The preparation process of regenerated cellulose membrane not only achieves environmental protection,but also greatly improves the cellulose concentration and the strength of the regenerated cellulose membrane.It can have broad application prospects in the fields of dyes and oily wastewater.