Department of Chemistry and Polymer Science, University of Stellenbosch, Private Bag X1, 7602 Matieland, South Africa.
Macromol Rapid Commun. 2013 Jul 12;34(13):1098-103. doi: 10.1002/marc.201300286. Epub 2013 May 31.
Thermal field-flow fractionation (ThFFF) is used as a novel fractionation technique to investigate the molecular heterogeneity of PB-b-PVP-b-PtBMA triblock copolymers. Such copolymers cause major problems in liquid chromatography due to very strong polar interactions with the stationary phase. ThFFF separates the copolymers with regard to size and/or chemical composition based on the normal and thermal diffusion coefficients. The separation mechanism in ThFFF and the chemical composition of the separated species is elucidated by online (1) H NMR. Based on the compositional analysis and a calibration of the system with the respective homopolymers, the samples are quantified regarding their molar masses, chemical compositions, and microstructures providing comprehensive information on the complex structure of these block copolymers.
热场流分级（ThFFF）被用作一种新颖的分级技术，用于研究 PB-b-PVP-b-PtBMA 三嵌段共聚物的分子多分散性。由于与固定相之间存在非常强的极性相互作用，此类共聚物在液相色谱中会引发重大问题。ThFFF 可根据正常和热扩散系数，基于尺寸和/或化学组成对共聚物进行分离。通过在线（1）H NMR 阐明了 ThFFF 中的分离机制和分离物种的化学组成。基于组成分析和用相应的均聚物对系统进行校准，样品的摩尔质量、化学组成和微观结构得以定量，从而提供了有关这些嵌段共聚物复杂结构的全面信息。
