Three Kinds Of Grafted Polymer Chain Based Preparation And Application Of Adsorption Separation Materials

It is a focus in separation science and macromolecules to prepare high performance adsorption and separation materials by grafting polymer chains with certain functional groups onto beads. This article based on the method of grafting to and grafting from, graftings three different polymer chains on the beads separately and makes three high performance adsorption and separation materials, which are applied to separate and adsorp protein or heavy metal ions.The details of this article are as follows:1. A series of temperature responsive polymers with different NIPAAm/MMA proportions were prepared via the copolymerization of N-isopropylacrylamide(NIPAAm) and methyl-methacrylate(MMA). Then a series of hydrophobic interaction chromatographic stationary phase with different hydrophobicity were prepared by grafting the temperature responsive polymers onto silica. Six standard proteins were employed to test separation performance of the synthesized stationary phase, the results showed that the stationary phase has good resolution for protein separation. The stationary phase was also employed to purify lysozyme from hen egg white and myoglobin from pig heart.2. At the presence of catalytic system CuCl/bpy, tert-butyl methacrylate (tBMA) was grafted onto the poly(chloromethylstyrene-co-divinylbenzene) beads via the surface-initiated atom transfer radical polymerization, then the grafted tBMA was hydrolyzed to produce a cationic exchange resin. Infrared spectroscopy was used to characterize its chemical composition. Lysozyme was used as a model protein, effect of reaction time of SI-ATRP, adsorption conditions, such as buffer pH, salt concentration on adsorption of lysozyme were investigated. The results showed that the prepared cationic exchange resin has very high adsorptive capacity and good repeatability for protein. The maximum capacity for lysozyme is up to192mg/g.3. At the presence of catalytic system CuCl/bpy, polyacrylonitrile (PAN) was grafted onto the poly(chloromethylstyrene-co-divinylbenzene) beads via the surface-initiated atom transfer radical polymerization, Infrared spectroscopy and elemental analysis were used to characterize its chemical composition. The grafted PAN was transformed into amidoxime (AO) via amidoximation transformation reaction with hydroxylamine hydrochloride, to form a chelating adsorbent. The adsorption of five heavy metal ions (Cu2+, Ni2+, Pb2+, Fe3+, Cr3+) on the chelating adsorbent were investigated. The results showed that the chelating adsorbent has good adsorptive capacity to Cu2+, Pb2+and Fe3+, while has little adsorptive capacity to Ni2+and Cr3+. The adsorption to Cu2+and Pb2+are chemical processes, and they are entropy driven. The effect of reaction time in SI-ATRP, buffer pH and equilibration time on adsorption of heavy metal ions were also investigated. After10successive use, the adsorption of modified beads to Cu2+was only reduced16.5%, implying that the prepared chelating adsorbent has good life time.