The Epoxy-modification Of Acrylic And Phenolic Resin

Immobilized biomolecules are currently the subject of great interest because ofconsiderable applied prospects and tremendous advantages over free ones.Immobilization of biomolecules on carriers involves to a variety of mechanisms,including physical adsorption, entrapment, cross linking, affinity and covalentbinding. Among them, covalent binding ensures biomolcules recycling andstabilization, facilitating its use in a continuous process. A lot of carriers withaldehyde, epoxy or cyano groups could react with nucleophilic groups onbiomolcules surface such as amino, hydroxyl and thiol groups via covalent bondsformation at near neutral pH without any kind of previous activation of biomolcules.In this context, epoxy supports have proved to be very suitable for covalentimmobilization of biomolcules.There were two major methods to prepare epoxy carrier, chemical synthesis andsurface modification. In this thesis, an epoxy-modification method of acrylic andphenolic resin was established through two steps, the modification effects wereevaluated via immobizing-galactosidase and examining its activity. Firstly, thecarboxyl or phenolic hydroxyl groups nucleophilicly substituted bromine atoms in3-bromopropene in ethanol solution, endowing the resin with allyl groups; secondly,introduced allyl groups was oxidized to epoxy groups by hydrogen peroxide underthe catalysis of acetic acid and manganese ion, endowing the resin with epoxygroups.Single factor experiment was adopted to study conditions of modification, theoptimal condition of binding reaction is binding time12h, binding temperature40℃, and dosage of bromopropene equivalent to3/4times of amounts of carboxylgroups of acrylic resin or phenolic hydroxyl groups of phenolic resin; the optimalcondition of oxidation reaction is oxidation time4.5h, oxidation temperature40℃,hydrogen peroxide concentration1.0mol·L^-1, acetic acid0.2mol·L^-1, andmanganese ion10^-3mol·L^-1. For further optimizing oxidation condtion,Box–Benknken design was used to test interaction effect between hydrogenperoxide, acetic acid and manganese ion. The structure of original, allyl-modified,epoxy-modified or enzyme-immobilized acrylic and phenolic resin was characterized by Fourier transform infrared spectrometer, the infrared spectrumindicated that allyl and epoxy groups were successfully introduced to resin andenzyme was successfully immobilized on resin.Epoxy-modified acrylic and phenolic resin could be used to immobilizebiomolcules such as enzyme, antibody or antigen etc., the immobilization processinvolves two mechanisms: firstly, quick physical adsorption, high ionic strengthwould contribute to exposure of the hydrophobic residues of ligands to solution,which could facilitate adsorption of enzyme to resin; secondly, multi-sites covalentbinding, the epoxy groups could react with nucleophilic groups such as amino,hydroxyl and thiol groups of ligands, leading to the binding of ligands to carriers viacabon–nitrogen, cabon–oxygen or cabon–sulfur single bonds. Thus, thisepoxy-modification method has potential application prospects for domains ofbiocatalysis, biosepration and bioanalysis ect.