BASF SE, GKP/R-G 201, D-67056 Ludwigshafen, Germany.
Anal Chim Acta. 2009 Nov 3;654(1):35-9. doi: 10.1016/j.aca.2009.05.001. Epub 2009 May 7.
In this contribution, we discuss the potential of low-field time-domain(TD)-NMR to study the swelling of (aqueous) polymer dispersions by a volatile solvent. Due to the sensitivity of transverse relaxation times (T2) to swelling-induced changes in the molecular dynamics of the polymer component, the effects of swelling can be measured without spectral resolution. The measurement is performed on polymer dispersions in native state with solids contents around 50% in a non-invasive way without separating the polymeric phase and the water phase from each other. Using acetone in two polyurethane (PU) dispersions with different hard phase contents, we explore the sensitivity of the method and present a data evaluation strategy based on multicomponent fitting and proton balancing. Furthermore, we report exchange continualization as a further effect that needs to be taken into account for correct interpretation of the data.
在本贡献中，我们讨论了低场时域（TD）-NMR 在研究挥发性溶剂对（水）聚合物分散体溶胀的潜在应用。由于横向弛豫时间（T2）对聚合物组分分子动力学因溶胀而产生的变化非常敏感，因此无需光谱分辨率即可测量溶胀的影响。该测量是在非侵入性的方式下，在不将聚合物相和水相彼此分离的情况下，在固体含量约为 50%的天然状态下的聚合物分散体中进行的。我们使用两种不同硬段含量的聚氨酯（PU）分散体中的丙酮，探索了该方法的灵敏度，并提出了一种基于多组分拟合和质子平衡的数据分析策略。此外，我们还报告了交换连续化作为另一个需要考虑的因素，以正确解释数据。
