The investigation of parallel‐column systems in gel permeation chromatography
The investigation of parallel‐column systems in gel permeation chromatography
复制标题
凝胶渗透色谱平行柱系统的研究
DOI：
10.1002/polc.5070210120
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发表时间：
2007
期刊：
影响因子：
--
通讯作者：
J. Pacco
中科院分区：
文献类型：
--
作者：
D. F. Alliet;J. Pacco
凝胶渗透色谱（GPC）是一种表征高分子材料分子量分布的新技术。物质的分离基于聚合物中的每个分子物质将扩散到交联聚苯乙烯凝胶中的深度。用于分离分子种类的适当凝胶的选择取决于聚合物中的均匀度。为了更好地理解各种凝胶的分离能力，进行了研究，以确定105、104和103 A中凝胶孔隙度的分子量限制。范围.进行了研究与一系列的阴离子聚合，窄分子量，标准聚苯乙烯，其特征在于光散射和膜和蒸汽压渗透压。分子量分布曲线（称为色谱图）以平均分子量（重均分子量Mw和数均分子量Mn）为特征进行描述。在合成聚合物中，分布比Mw/Mn的范围相当大。为了从GPC色谱图得到重均或数均，平均链长必须乘以Q因子，即每埃当量直链长度的分子量。窄分子量分布的结果表明，105、104和103 A.凝胶限于特定的分子量范围。104 A。柱系统给出了GPC和绝对方法之间的最佳相关性。
Gel permeation chromatography (GPC) is a new technique for characterizing the molecular weight distribution of polymeric materials. The separation of species is based upon the depth to which each molecular species in a polymer will diffuse into a crosslinked polystyrene gel. The selection of the proper gel to use for separating molecular species depends upon the degree of homogeneity in a polymer. For a better understanding of the separating ability of the various gels an investigation was carried out, to establish the molecular weight limitations of gel porosities in the 105, 104, and 103 A. ranges. The study was carried out with a series of anionically polymerized, narrow molecular weight, standard polystyrenes, which have been characterized by light scattering and membrane and vapor-pressure osmometry. Molecular weight distribution curves, called chromatograms, are characteristically described in terms of average molecular weights: weight-average molecular weight Mw and number-average molecular weight Mn. The range of distribution ratios Mw/Mn is quite large in synthetic polymers. To give the weight average or number average from a GPC chromatogram, the average chain lengths have to be multiplied by a Q factor, the molecular weight per angstrom of equivalent straight-chain length. The results for narrow molecular weight distributions show that the separating ability of the 105, 104, and 103 A. gels is limited to specific ranges of molecular weight. The 104 A. column system gave the best correlation of results between GPC and the absolute methods.