表面亲水性粒度单分散交联PMMA树脂的合成及表征

用种子溶胀聚合方法 ,合成出了粒度单分散的交联聚甲基丙烯酸甲酯微球 .将微球通过水解 ,使其转化为表面带羧基的树脂 .分别用多糖化合物Dextran和DEAE Dextran对水解树脂表面进行包覆涂层 ,然后用n 丁二醇双环氧丙醚分别进行交联 ,制备出两种表面带高交联多糖覆盖层的树脂 .以两种改性树脂为填料 ,以人血清蛋白为试样 ,用HPLC方法对树脂的亲水性能进行了表征 .研究表明 ,两种改性树脂均有很好的亲水性 ,蛋白质的回收率分别在 97%和 99%以上 ,并有良好的机械强度和化学稳定性

PREPARATION AND CHARACTERIZATION OF MONOSIZED CROSS-LINKED PMMA RESINS WITH HYDROPHILIC SURFACE

This paper presents the novel monosized resins with hydrophilic surface coated polysaccharides,including synthesis of the matrix beads,modification of the particle surface and characterization of HPLC properties of the modified products.The monosized matrix beads based on poly(methyl methacrylate co divinylbenzene)(PMMA DVB) were synthesized by seed swelling polymerization.The linear polystyrene particles as seeds were swollen by an emulsifying mixture of monomer,cross linker and initiator in the aqueous solution containing stabilizer at the room temperature,then the swelling products were polymerized in the same solution system at 70℃,finally the polymerization products were fully washed with water.The particle parameters and apparent morphology of the matrix beads were characterized by scanning electron microscopy (SEM).The results show that the polymerization method is suitable to the preparation of monosized PMMA DVB beads with particle diameters of 5～15 μm,the particle dispersion coefficient of the polymerization products with different cross\|linking densities is less than 2%.After being hydrolyzed with a 30%( W/V ) NaOH solution at 80℃,the PMMA\|DVB beads were transformed into the hydrolyzed resins containing carboxylic groups on the particle surface.Dextran and DEAE\|Dextran were coated respectively by the impregnation method,and then were cross\|linked respectively with 1,4\|butanedol diglycidyl ether as cross\|linker.Two new modified resins with covering layer of cross\|linked polysaccharides on the particle surface were obtained.The polysaccharides content of the modified resins was about 7%( W/W ) of the matrix beads.In order to get a uniform covering layer,the coating and cross\|linking process was generally divided into two or three times to accomplish with same operation method.SEM observation showed that the physical morphology of the two modified resins still kept monodisperse particle as matrix beads.Owing to highly cross\|linking network structure,the modified resins exhibit good physical and chemical stability.The particles can withstand high pressure operation,can be treated with acidic and alkaline solutions (pH=1～14).Monodisperse particle size,good particle rigidity and the surface coated by polysaccharides make the modified resins as HPLC packings possessing high column efficiency,high permeability and excellent hydrophilic properties.The experiments show that on chromatographic columns packed with the two modified resins,human serum albumin possesses good elution behavior in elution system of phosphate buffer (pH=3 8),the protein recovery is over 97% and 99% respectively.