利用原子转移自由基反应在超大孔聚苯乙烯微球表面接枝含糖聚合物刷

Grafting Glycopolymer Brushes onto Gigaporous Polystyrene Microspheres via Atom Transfer Radical Polymerization

超大孔聚苯乙烯微球具有力学强度高、化学稳定性好、传质速率快等优点,但其表面疏水性强,无法衍生,要想用作生物大分子分离介质必须对其亲水改性。文中利用原子转移自由基(ATRP)反应的方法在超大孔聚苯乙烯微球(PS)表面原位接枝含糖聚合物刷,得到亲水改性的超大孔聚苯乙烯微球。对溶剂、配体、催化剂及温度等反应条件进行了详细考察,优化了接枝反应条件。含糖聚合物刷最大接枝量达到490.8 mg/g干球,改性后微球表面接触角由124°下降到42°,对蛋白的吸附量也降低了10.2倍,亲水性和生物相容性明显提高,同时微球的超大孔未被堵塞,且柔性含糖聚合物刷在后期衍生过程中还起到了"间隔臂"的作用,将是一种非常优良的生物大分子分离介质,在快流速蛋白分离色谱领域有很大应用潜力。

Gigaporous polystyrene(PS)microspheres were characterized with high mechanical strength,good chemical stability and excellent mass transfer property.However,the hydrophobic surfaces of PS microspheres limit their application in bioseparation medium except by further hydrophilic modification.In this study,glycopolymer brushes grafting gigaporous PS microspheres(PS-PMAGlu)were successfully fabricated through the three-step reaction.Bromoisobutyryl groups were first coupled on PS microspheres through Friedel-crafts reaction to prepare a solid atom transfer radical polymerization(ATRP)initiator(PS-Br).Then,poly(3-O-methallyl diacetone-D-glucose)brushes were grafted onto PS-Br microspheres(PS-PMADAGlu)via ATRP.Finally,PS-PMAGlu microspheres were obtained by formic acid hydrolysis to remove the protective groups of glucose moiety.In order to realize the control of grafting amounts of glycopolymer brushes,the grafting conditions were optimized by investigating the solvents,ligands,catalysts and temperature,and the maximum grafting amount of glycopolymer brushes is 490.8 mg/g dry microspheres.PS-PMAGlu microspheres were characterized by Fourier transform infrared(FT-IR)spectra,X-ray photoelectron spectroscopy(XPS),scanning electron microscope(SEM),mercury porosimetry measurements,water contact angle measurements,and protein adsorption experiments.After grafting glycopolymer brushes,the hydrophilicity of PS microspheres is greatly improved and their gigaporous structures are well maintained.The water contact angle of PS-PMAGlu microspheres decreases significantly from 124°to 42°.The adsorption amount of bovine serum albumin(BSA)on PS-PMAGlu microspheres is 10.2 times lower than that on PS microspheres.In addition,the flexible glycopolymer brushes can serve as spacer arm in the following derivatization,which will facilitate the interaction between ligands and biomacromolecules.All the results indicate that glycopolymer brushes grafting PS microspheres are promising in high-speed protein chromatography after further derivatization.