Fraunhofer Institute for Structural Durability and System Reliability LBF, Division Plastics, Group Material Analytics, Schlossgartenstr. 6, 64289 Darmstadt, Germany.
J Chromatogr A. 2013 Apr 12;1285:40-7. doi: 10.1016/j.chroma.2013.01.067. Epub 2013 Feb 17.
High-temperature two-dimensional liquid chromatography (HT 2D-LC) was developed for the separation and characterization of functional polyolefins. Therefore, the key experimental parameters, namely the injection volume, the mobile phase composition, the flow rate in SEC and the time and phase of sampling into the second dimension, were systematically varied and their influence on the resolution of separation were studied. The HPLC separation of ethylene-vinylacetate waxes was realized using silica gel as stationary phase and a solvent gradient decalin→cyclohexanone, while SEC separations were realized in the chromatographic system polystyrene divinyl benzene column/1,2,4-trichlorobenzene. By choosing suitable experimental parameters, the run time needed for one complete 2D-LC analysis of a polymer sample was shortened from about 200 min to 100 min. However, the developed method failed to adsorb polypropylene and ethylene/1-butene copolymers grafted with 13 or 3 mol.% of methyl methacrylate respectively. Using porous graphite as a stationary phase and a solvent gradient 1-decanol→1,2,4-trichlorobenzene as mobile phase 2D-LC separations of both grafted polyolefins were realized.
高温二维液相色谱（HT 2D-LC）用于分离和表征功能化聚烯烃。因此，系统地改变了关键实验参数，即进样量、流动相组成、SEC 中的流速以及进入二维的采样时间和阶段，并研究了它们对分离分辨率的影响。使用硅胶作为固定相和溶剂梯度 decalin→cyclohexanone 实现了乙烯-醋酸乙烯酯蜡的 HPLC 分离，而 SEC 分离则在聚苯乙烯-二乙烯基苯柱/1,2,4-三氯苯的色谱系统中实现。通过选择合适的实验参数，将聚合物样品完整的 2D-LC 分析所需的运行时间从约 200 分钟缩短到 100 分钟。然而，该方法未能吸附聚丙烯和分别接枝 13 或 3 mol.%甲基丙烯酸甲酯的乙烯/1-丁烯共聚物。使用多孔石墨作为固定相和溶剂梯度 1-癸醇→1,2,4-三氯苯作为流动相 2D-LC 实现了这两种接枝聚烯烃的分离。
