Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), UMR 7104, 1 rue Laurent Fries, BP 10142, 67404 Illkirch cedex, France.
J Magn Reson. 2011 Sep;212(1):169-73. doi: 10.1016/j.jmr.2011.06.020. Epub 2011 Jul 1.
The polydispersity of a polymer chain is usually measured by its polydispersity index (PDI). In this study we present a method which allows to estimate the PDI of linear polymers from a simple diffusion experiment. The approach is based on the differential diffusion profile observed for the main polymer chain signal versus the extremity signal. From this difference, a statistical analysis of the DOSY spectrum allows the PDI to be estimated accurately, to the condition that the Flory coefficient of the polymer chain is known. Alternatively, the mass average molar mass Mw and the number average molar mass Mn can be extracted separately from the same spectrum. Results on PEO mixes reveal that, using this new method, PDI can be estimated with a very good accuracy. This method can easily be applied to almost any kind of linear polymers.
聚合物链的多分散性通常通过其多分散指数（PDI）来衡量。在本研究中，我们提出了一种方法，该方法可以通过简单的扩散实验来估计线性聚合物的 PDI。该方法基于观察到的主聚合物链信号与末端信号之间的差分扩散分布。通过对 DOSY 光谱进行统计分析，可以在已知聚合物链的 Flory 系数的情况下，准确估计 PDI。或者，可以从同一光谱中分别提取质量平均摩尔质量 Mw 和数均摩尔质量 Mn。在 PEO 混合物上的结果表明，使用这种新方法，可以非常准确地估计 PDI。该方法可以轻松应用于几乎任何类型的线性聚合物。
