The Enzymatic Polymerization Of Phenolics And Their Adsorptivity Of Ag~+

Enzyme is extensively used in the field of organic synthesis because of its unique advantage, however,the enzymatic polymerization has not been reported too much.In recent years, enzymatic synthesis ofphenol polymers has received much attention for preparing phenolic resins.Polymerization of phenol is synthesized by HRP and H2O2in the new system (buffer-BTEAC).Because of no organic solvent, the high efficiency of enzyme is maintained in this system, showing thecharacteristics of low cost, high efficiency, green environmental protection, which makes the practicalperformance of enzymatic polymerization of phenol greatly increased. When the dosage of BTEACgrowes form0.1g to0.5g polymer, the yield of phenol monotonically rises with increasing dosage ofBTEAC and finally could get64%. The polymerization produced the polymer with high conversion inbuffer pH value ranging from4to10, and the increasing pH value of the buffer solution resulted in phenolpolymers with increasing yields. Due to the structure of polyphone containing hydroxyl, polymerization ofphenol is used in the adsorption of Ag+adsorption, but the result is not very good.TBAB was used as an additive, and the new system (TBAB-buffer) was formed. In this system,phenol was used as monomer, and horseradish peroxide was used as a catalyst, the enzymaticpolymerization of phenol was proceeding successfully. When the addition of TBAB was0.6g, theconversion of phenol could be up to99%.The polymerization reaction can be proceed in a wide pH valuein a range from4to10. The conversion of phenol was increased with the pH value. However, in carbonatebuffer solution of pH=10, the conversion of phenol could reach95%.The effect of TBAB is obviouslybetter than that of BTEAC, because the structure of BTEAC contains benzene ring. The enzymatic polymerization of amino-phenol was proceeding under mild conditions. Besides theinfluence of buffer solution, pH value and the dosage of hydrogen peroxide werediscussed. Poly(p-aminophenol) also can be produced in a wide pH value in a range from4to10,however, the yield decreased with the pH value. When the pH value arrived at4,5and6, the yield wasmore than90%, and when pH was8, the yield was only40%. Because the structure of p-aminophenolcontains both hydroxyl and amino, the Poly(p-aminophenol) was used for the adsorption of Ag+. It wasfound that concentration of Ag+, temperature, pH value and reaction time have an important role inthis adsorption. When the concentration of Ag+was1000ppm, the maximum adsorption capacity ofpolymer on Ag+could reach220mg/g. The adsorption capacity of polymer increased with thetemperature. The pH value of the solution also affected the adsorption. When the pH value was2, theadsorption of polymer on Ag+was only50%. But when the pH value was6, adsorption of polymer couldreach100%. The polymers were characterized by XRD, XPS and SEM, it was found that the polymerchanged Ag+to silver nano-particle. The particle size of Ag was10nm, which indicated that theadsorption of phenol on the silver ions was reduced adsorption.