Laboratory for Advanced Separations Technologies, Department of Chemistry and Geochemistry, Colorado School of Mines, Golden, CO 80401, USA.
J Chromatogr A. 2011 Sep 28;1218(39):7016-22. doi: 10.1016/j.chroma.2011.08.007. Epub 2011 Aug 12.
A theory-based approach is presented for the development of thermal field-flow fractionation (ThFFF) of polyacrylates. The use of ThFFF for polymer analysis has been limited by an incomplete understanding of the thermal diffusion which plays an important role in retention and separation. Hence, a tedious trial-and-error approach to method development has been the normal practice when analyzing new materials. In this work, thermal diffusion theories based on temperature dependent osmotic pressure gradient and polymer-solvent interaction parameters were used to estimate thermal diffusion coefficients (D(T)) and retention times (t(r)) for different polymer-solvent pairs. These calculations identified methyl ethyl ketone as a solvent that would cause significant retention of poly(n-butyl acrylate) (PBA) and poly(methyl acrylate) (PMA). Experiments confirmed retention of these two polymers that have not been previously analyzed by ThFFF. Theoretical and experimental D(T)s and t(r)s for PBA, PMA, and polystyrene in different solvents agreed to within 20% and demonstrate the feasibility of this theory-based approach.
提出了一种基于理论的方法来开发聚丙烯酸酯的热场流分级（ThFFF）。ThFFF 用于聚合物分析的应用受到限制，因为对在保留和分离中起重要作用的热扩散的理解不完整。因此，当分析新材料时，通常采用繁琐的反复试验方法来开发方法。在这项工作中，基于温度相关渗透压梯度和聚合物-溶剂相互作用参数的热扩散理论用于估计不同聚合物-溶剂对的热扩散系数（D（T））和保留时间（t（r））。这些计算确定甲乙酮是一种会导致聚（正丁基丙烯酸酯）（PBA）和聚（甲基丙烯酸酯）（PMA）显著保留的溶剂。实验证实了这两种以前未通过 ThFFF 分析的聚合物的保留。在不同溶剂中 PBA、PMA 和聚苯乙烯的理论和实验 D（T）和 t（r）之间的差异在 20%以内，证明了这种基于理论的方法的可行性。
