MMA-EDMA聚合物微球型和包覆硅胶型填料的制备与色谱性能

以Methyl methacrylate(MMA)和Ethylene dimethacrylate(EDMA)作为单体制备了多孔聚合物微球型(PG)和硅胶基质聚合物包覆型填料(PCSG).经电子显微镜、元素分析、尺寸排阻色谱和反相液相色谱对多孔聚合物微球粒径、硅胶基质聚合物包覆程度、交联剂添加对填料微孔构造的影响、非极性和极性化合物的色谱保留行为进行了评价和讨论.结果显示:PG和PCSG填料制备过程中形成了与C18填料不同的微孔结构;PG填料的大微孔体积Vb最大,PCSG填料小微孔体积Va最大.PG和PCSG填料的小微孔体积Va的不同导致填料表面具有相同的MMA高分子链却表现出不同的疏水性能;大微孔体积Vb的存在使填料对大体积芳香族化合物分离表现出了与C18填料不同的立体选择性.PG和PCSG填料因其表面残留有相同的MMA高分子链,使其对极性芳香族化合物表现出了相似的色谱保留行为.PCSG填料的柱效能介于C18和PG填料之间.

Preparation and Chromatographic Characterization of Polymeric Microspheres and Polymer Coated Silica Parking Material with the MMA-EDMA

The polymer gel （PG） and polymer coated silica gel （PCSG） parking materials were produced with the methyl methacrylate （MMA）and ethylene dimethacrylate （EDMA）. With the scanning electron micrograph, the elemental analysis, the size exclusion chromatography and the reversed phase liquid chromatography, we evaluated and discussed the parking materials＇ various features, including its diameter of microspheres, polymer coated degree,cross-linked effect for the micropore structure, and the chromatographic retention behavior against the polar and non-polar compounds. The result shows that PG and PCSG display different micropore structure comparing to C18 ;PG has the largest micropore volume Vb, and PCSG has the largest micropore volume Va. The difference between the micropore volume Va of PG and that of PCSG resuhs in their different hydrophobic properties,even though PG and PCSG have the same MMA polymer chain on the surface. Comparing to C18 ,the parking materials display different stereoselectivity for separation of bulky and planar aromatic compounds due to their micropore volume Vb. Since the remaining MMA polymer chains on the surface are the same for PG and PCSG,the parking materials show similar chromatographic retention against the polar compounds. The column efficiency of PCSG is between that of C18 and that of PG.