Preparation of Carboxymethylcellulose Picric Acid Ester and Adsorption Property for Creatinine
Ether of carboxymethylcellulose-based picric acid(CMC-PA) was prepared from carboxymethylcellulose(CMC) and picric acid(PA) by the mild reactive conditions of acidylation with chloric.The strcture of CMC-PA was characterized by FTIR,Element analysis,XRD and CPMAS13C NMR.Influences of reaction conditions,such as reaction temperature,reaction time,ratio of CMC to PA and amount of pyridine,were studied by mass fraction of nitrogen.Result showed that the synthetical conditions were obtained as ratio of CMC to PA 2 : 1 (by weight),amount of pyridine 50 mL,reaction temperature 85°C and reaction time 4 hours.The adsorption property of CMC-PA to creatinine was studied under simulated biological human body conditons.The kinetic and isothermal curve were given. Results showed that adsorption amount reached an equilibrium value after 10 hours,and the maximum adsorption amount was 1.75mg/g.Equilibrium data of creatinine fit well with Freundich equation,indicating that the adsorption was mainly chemical monolayer adsorption .The Freundich indx(1/n) was less than 1,which implied that the adsorption was preferential process.