Preparation Of Carboxymethyl Cellulose-Picric Derivatives And Its Adsorption Property For Creatinine And Urea

The research was supported by grants from Specialized Research Fund for the Doctoral Program of Higher Education (SRFDP) (No.20060225008) and Northeast Forestry University Graduate Student Project.Chronic renal failure I is a clinical syndrome because of a large number of toxin that are urea and creatinine in the body.So the removal of their excess has been a major problem for patients suffering from chroic renal failure,and the oral adsorbent is an effective method of treating chronic renal failure.In this paper a series of carboxymethyl cellulose derivatives were developed with carboxymethyl cellulose as carrier.These derivatives are oxidized carboxymethylcellulose, carboxymethyl cellulose picric acid ester, carboxymethyl cellulose picric acid ester, oxidized carboxymethyl cellulose picric acid ester,and they were prepared as a new composite oral adsorbent for chronic renal failure and that uesd for adsorption of urea and creatinine.Their stability and adsorption were compared,and the adsorption for vitamin B6 which is important in bady was determined in the meantime. The research was supported by grants from Specialized Research Fund for the Doctoral Program of Higher Education (SRFDP) (No.20060225008) and funded project of northeast forestry university graduate thesis(j2am02).Oxidized carboxymethylcellulose was prepared from acidulated CMC with periodate sodium as oxidant in acidic conditions. Oxidized CMC was characterized by XRD, FTIR, element analysis and measuring the aldehyde group(alkali melt method of measuring the baldheaded content).Influences of adsorption of urea,such as reaction temperature,reaction time,ratio and amount ph value, were studied. The relation between the aldehyde content of oxidized CMC and the urea adsorption capacity was discussed. The adsorption equilibrium and kinetics of urea onto oxidized CMC were studied. The results showed that the optimal synthetical condition was that the ration of NaIO4 to was CMC 4 to 1 by weight, the reaction temperature was 50°C, the reaction time was 3 hours and pH was 2, with aldehyde content of 85.23%and a yield of 80.5%under this condition. When the adsorption temperature was 37°C and pH was 7, the max AC of urea was 38.60 mg/g and adsorption equilibrium reached after 6 hours under simulated biological human body conditons.. The adsorption isotherm curve of DAC fit with Freundich equation. Values of isosteric adsorption enthalpy, Gibbs adsorption energy, and adsorption entropy were calculated according to the relationship of thermodynamic function and the adsorption behaviors are reasonably interpreted. The adsorption of urea on oxidized CMC was a chemically endothermic process.Ester 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 structure 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.CMC-PA had been already synthesized by FITR,Element analysisi,and CPMAS13C NMR.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 isothermy 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 creatine fit well with Freundich equation,indicating that the adsorption was mainly chemical adsorption.The Freundich indx(1/n) was less than 1,which implied that the adsorption was preferential processThe stability properties of CMC-PA were studied under simulated body conditions, determined at 358 nm by UV spectrum. The influence of pH value, hydrolysis time and storage period to stability of CMC-PA was studied.At different times, CMC-PA on the adsorption properties of vitamin B6 was measured for the determination of the wavelength to 303nm. The results show that in the buffer solution of pH valuesl,2,8,the hydrolysis rate of CMC-PA is 0.47%～0.69%,0.213%～0.226%.1.318%～1.418% between 4 to 6 hours respectively. When CMC-PA is exposured at room temperature for 2,4,6,8 months, the Saturated adsorption capacity of CMC-PA for creatinine didn't change obviously compared with new-made CMC-PA. In addition, CMC-PA has no obvious adsorption of vitamin B6 at different time conditions.Sodium periodate as selective oxidant, oxidized carboxymethylcellulose was prepared from acidified cellulose sodium carboxymethyl under acidic conditions. Composite targeted oral adsorbent ester of carboxymethylcellulose-based picric acid(CMC-PA)was prepared by reaction with picric acid. The structure of CMC-PA was characterized by XRD, FTIR, Element analysis and Chemical functional determination (alkali fusion method to measure aldehyde content), the results showed that CMC-PA has generated;.the adsorption property of CMC-PA to urea and creatinine was studied under simulated biological human body conditions, results showed that adsorption amount reached an equilibrium value after?, aldehyde content is?;the saturated adsorption capacity to urea and creatinine was respectively. At 20-50°C and the concentration range studied, the adsorption isotherms of urea and creatinine in DCNB fit well with Freundich equation, indicating that the adsorption was mainly chemical adsorption. The Freundich index(1/n) was less than 1,which implied that the adsorption was preferential process. endothermic process and that of creatinine was a spontaneous exothermic process.