Study On Preparation And Properties Of Polymers Of Phenols Monomer With HRP/H₂O₂

In this research topic, free radical polymerization of phenols monomers were carried out using horseradish peroxidase (HRP/H₂O₂) as catalyst, several different phenols monomers polymerization and factors that affect the polymerization were studied. The structure of the copolymers were characterized and the reaction mechanism was researched. The research topic has positive significance to preparation of green leather tanning agent on theory and practice.Firstly, the synthesis and properties of 4-hydroxy benzosulfonate (PHS) polymer by HRP/H₂O₂ were researched. The selection of pH controller in polymerization system and the application experiment of synthetic products were discussed. The results show that as pH buffer, the control of Na₂CO₃ or NaHCO₃ to system pH was good, the consumption was small and the final yield of product were about 97%, the mass of Na₂CO₃ is less than that of NaHCO₃ and the control stability of Na₂CO₃ is the best, so Na₂CO₃ is the optimum pH buffer of HRP/ H₂O₂ catalysis. The poly (4-hydroxy benzosulfonate) was used for tanning test, the application results show that poly (4-hydroxy benzosulfonate) has excellent effect in tanning, softening leather fibres and improving dyeing.Secondly, the preparation and application of p-hydroxybenzaldehyde (PHB) and PHS copolymer were studied. The copolymer of PHB and PHS was synthesized by means of radical copolymerization and the reaction was catalyzed by HRP/H₂O₂. The aldehyde group protection and effects of system pH, polymerization temperature, ratio of monomers, amount of HRP and H₂O₂ dropwise time on copolymerization were investigated. The ideal copolymer was synthesized in solution composed of deionized water 50 g and sodium carbonate 1 g when the molar ratio of PHBEA and PHS was 3:1 and the amount of PHBEA and PHS was 9.84 g, and catalyst was HRP/H₂O₂ at 30°C for 3.5 h, the amount of HRP was 0.0025 g, the dropwise time of 7.57 g 30% H₂O₂ was 60 min, the pH value was 8.0 and PHB-PHS copolymer was obtained by acidolysis reaction at last. The weight yield of copolymer was about 96%. The structure and properties of the copolymer were characterized by FTIR and NMR. The applied results show that the shrinkage temperature increasment (ΔTs) of leather was 20°C and the copolymer has assisting dyeing and tanning properties.At last, resorcinol and 3,5-dihydroxy benzoic acid copolymer was synthsized with HRP/H₂O₂ as catalyst. It was a kind of aromatic retanning agent no content of formaldehyde. The applied result show that retanned leather have excellent filling properties and good dye effect, the structure of resorcinol and 3,5-dihydroxy benzoic acid copolymer copolymer were characterized by FTIR and NMR. The polymerization of phenols monomer occurred in ortho and para position of phenolic hydroxy. The polymerization mechanism of phenols with HRP/H₂O₂ as catalyst was researched. It is the characteristics of polymerization mechanism of phenols that not only abide by reaction rules of enzyme and substrate, but also free unique radical copolymerization rules.The innovation in this study was PHS, PHS-PHB, resorcinol and 3,5-dihydroxy benzoic acid polymer tanning agents were synthesized with HRP/H₂O₂ and the selection of pH controller was stuied in HRP/H₂O₂ catalytic polymerization system to solve the problem of pH control.