Research On Preparation And Adsorption Property Of Tannin-immobilized Cellulose Resin

Phenolic hydroxyl groups is a good hydrogen bond donor,which are easy to form hydrogen bonds with organic compounds containing hydrogen bond receptor groups.The phenolic hydroxyl modified adsorption resin may be prepared by the introduction of phenolic hydroxyl groups into the polymer structure.Tannin is a kind of widely existed in plant polyphenols,the molecular structure contains have a lot of phenolic hydroxy.The phenolic hydroxyl can bind to proteins,alkaloids,polysaccharides and exhibiting specific affinity to metal ions.In this paper,tannin-immobilized on cellulose resin were prepared by using bayberry tannin and cellulose as raw materials.Rigid cellulose can provide a supporting framework for the resin network,which will enhance the strength of the adsorption resin and improve the adsorption properties of resin.This study laid a foundation for the application of tannin-immobilized on cellulose resin in the treatment of dye wastewater and the separation and purification of alkaloids.The main contents are as follows:1.The poly(tannin)-cellulose resin was synthesized by inversing suspension cross-linking reaction of tannin-phenolic polymer and cellulose with epichlorohydrin as crosslinking agent,where tannin-phenolic polymer was prepared by crosslink of tannin with paraformaldehyde.Tannin was crosslinked prior to being immobilized on cellulose,which could increase the effective phenolic hydroxyl content in cellulose skeleton and improve the adsorption property of poly(tannin)-cellulose resin.poly(tannin)-cellulose resin has high adsorption capacity for methylene blue,the maximum adsorption capacity of berberine hydrochloride on poly(tannin)-cellulose resin was 187.62 mg/g.2.The spherical poly(tannin)-cellulose resin was synthesized by inversing suspension cross-linking reaction of tannin-phenolic polymer and cellulose with epichlorohydrin as crosslinking agent.The spherical poly(tannin)-cellulose resin has a porous structure and a large amount of phenolic hydroxyl groups in polymer network.The spherical poly(tannin)-cellulose resin has high adsorption capacity for methylene blue and berberine hydrochloride,the maximum adsorption capacity of methylene blue and berberine hydrochloride on spherical poly(tannin)-cellulose resin were 339.64 mg/g and 245.92 mg/g,respectively.The adsorption isotherms and kinetics of spherical poly(tannin)-cellulose resin for methylene blue and berberine hydrochloride can be well fitted by the Langmuir equation and pseudo-second-order model,respectively.The data of thermodynamic analysis suggest that the adsorption for methylene blue and berberine hydrochloride on spherical poly(tannin)-cellulose resin was a exothermic adsorption process.3.Tannin-immobilized on aldcellulose resin was prepared by the phenolic reaction of tannin immobilized on aldocellulose,where aldocellulose was prepared by theoxidation of cellulose with sodium periodate.The method of immobilized tannin is environmentally-friendly due to the lack of cross-linking agent.The adsorption properties of tannin-immobilized on aldocellulose resin for berberine hydrochloride were investigated,the adsorption capacity of berberine hydrochloride on tannin-immobilized on aldocellulose resin was 143.66 mg/g.The adsorption isotherms and kinetics of tannin-immobilized on aldocellulose resin for berberine hydrochloride can be well fitted by the Langmuir equation and pseudo-frist-order model,respectively.The data of thermodynamic analysis suggest that the adsorption for berberine hydrochloride on tannin-immobilized on aldocellulose resin was a exothermic adsorption process.