| Tannin is a kind of widely existed in plant polyphenols.It is one of the ways to realize the high value utilization of biomass resources by using tannin as raw material to prepare polyphenol adsorption resin.In this paper,tannin-based phenolic resin modified by resorcinol was prepared with tannin,resorcinol as raw material,formaldehyde as crosslinking agent.And the adsorption property for caffeine was investigated.Adsorption resin based on cellulose derivatives and tannin was prepared by the crosslinking reaction of tannin based phenolic resin and cellulose derivatives with epichlorohydrin as crosslinker.The adsorption properties of cationic dyes were discussed.The main contents are as follows:1?Tannin-based phenolic resin modified by resorcinol was prepared with acacia mangium tannin,resorcinol as raw material,formaldehyde as crosslinking agent.SEM analysis showed that the resin particles were well dispersed.The resin showed good adsorption performance for caffeine because of the chain extension effect of resorcinol resin,increases the space network structure,advantageous to the infiltration of caffeine molecules.The maximum adsorption capacity of resin to caffeine was over 200 mg/g.The isothermal adsorption of phenolic resin for caffeine was agreement with the Freundlich isotherm equation.Pseudo-second-order kinetic model could be used to interpret the adsorption kinetics.2?Adsorption resin based on hydroxyethyl cellulose and tannin was prepared by the crosslinking reaction of tannin based-phenolic resin and hydroxyethyl cellulose with epichlorohydrin as crosslinker.FTIR analysis results showed that tannin successfully cured to hydroxyethyl cellulose;SEM analysis showed that adsorption resin based porous structure.The resin showed good adsorption performance for methylene blue because of the combination of tannin based-phenolic resin and hydroxyethyl cellulose effectively increased the adsorption sites in the adsorption resin network.The maximum adsorption capacity of adsorbent for methylene blue can reach 300 mg/g.The isothermal adsorption of phenolic resin for methylene blue was agreement with the Langmiur isotherm equation.Pseudo-second-order kinetic model could be used to interpret the adsorption kinetics.3?Adsorption resin based on carboxymethyl cellulose and tannin was prepared by the crosslinking reaction of tannin based-phenolic resin and carboxymethyl cellulose with epichlorohydrin as crosslinker.FTIR analysis showed that the crosslinking reaction occurred between the phenol formaldehyde resin and sodium carboxymethyl cellulose.SEM analysis showed that the resin had the characteristics of rough surface.The combination of tannin based-phenolic resin and carboxymethyl cellulose can effectively improve the adsorption performance of adsorption resin for methylene blue and methyl violet by the synergy effect between phenolic hydroxyl of tannins and carboxyl of carboxymethyl cellulose.In the static adsorption process,the maximum adsorption capacity of adsorbent for methylene blue and methyl violet can reach 1300 mg/g,1200 mg/g.The isothermal adsorption of phenolic resin for methylene blue and methyl violet were agreement with the Langmiur isotherm equation.Pseudo-second-order kinetic model could be used to interpret the adsorption kinetics.It can be known that the Thomas model can describe the dynamic adsorption process of methylene blue. |
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