Research On Preparation And Application Of New Amino Resin By Mannich Reaction

Amino polystyrene resin,because of its excellent property, is widely applied inbioseparation, waste water treatment, catalyst loading, immobilization of enzyme, andpreparation of chelating resin, etc. but this kind of resin is usually prepared bychloromethylation method which used chloromethyl methylether as reactant, which isstrong carcinogen, and secondary crosslinking due to methylene bridge exists in thechloromethyl polystyrene.Therefore, in this paper, the new amino resin(PS-EDA and PS-TEPA) was preparedfrom acetylated polystyrene micro-beads, formaldehyde and tetraethylene pentamine(or ethylenediamine ) by Mannich reaction, which can substitute anion-exchange resinprepared from chloromethyl polystyrene resin and as immobilization support ofenzyme. Influence factors such as molar ratio of materials, reaction temperature andtime, feeding methods as well as water in ethanol media were discussed. The optimumexperimental conditions were as follows: amine: formaldehyde: hydrochloride:acetyl=10:10:3.3:1, and reaction temperature=100℃,reaction time=12hours. Underthese experimental conditions, the product containing nitrogen 13.7mmol/g wasobtained. Multi-substitution reaction of acetyl was demonstrated in study on reactionmechanism."Flexible immobilized enzyme"model is indicated, that is: the flexible carrier isprepared by linking a hydrophilic and flexible polymer chain on the suface of thesupport, then enzyme is connected on the carrier by covalent bond. Dialdehyde starch(DAS) as flexible chain and glutaraldehyde as arm spacer are coupled with the aminopolystyrene micro-sphere supports, then papain is immobilized on the flexible supportand arm spacer support. The experiment results show that DAS are coupled with theamino supports loading 1.0~2.0mmol/g of –NH2 firstly(aldehyde:amino(mole)=5),then papain are coupled with the flexible support, and activity recovery ofimmobilized papain is 40~50% on the flexible support, whereas only 20~30% on armspacer support. Therefore, the "Flexible Immobilized Enzyme"model can overcomethe deficiency of arm spacer immobilization. Flexibly immobilized enzyme is much iAbstractmore stable than free enzyme, and flexibly immobilized enzyme's storage half life isabout 30~40 days at the room temperature.The new aminocarboxylic acid chelating resin are synthesized from PS-EDA andPS-TEPA, and carboxyl groups loading is 2.4mmol/g and 3.7mmol/g respectively.Aminophosphonic acid chelating resin is synthesized from PS-TEPA.aminophosphonic acid chelating resin loading 1.6mmol/g of phosphorous acid groupsis obtained.The static adsorption character of the resins for Cu2+,Zn2+ and Ni2+ arepreliminary studied. The adsorption capacities of AP resin for Cu2+,Ni2+ are 1.1,0.69mmol/g respectively at 25℃,which is the highest among three kinds of chelatingresins. The adsorption capacities of AC2 resin for Zn2+ is the highest among threekinds of chelating resins, and is 1.35mmol/g.The static adsorption capacities of resins chelated metal ion for Bovine serumalbumin Fraction V (BSA-V) are preliminary measured. Adsorption capacities ofthree kinds of chelating resins for BSA-V are the highest at pH=7.6 and 25℃. Theadsorption capacities of resin chelated Cu2+ for BSA-V is more than that of resinchelated Zn2+and Ni2+. To the same metal ion, The adsorption capacities of AC2 resinfor BSA-V is the most among three kinds of chelating resins.