High-resolution solid-state NMR studies of polymer chemical and physical structures

Even though concentrated polymer solutions and melts are macroscopically viscous systems, they exhibit high resolution NMR spectra when recorded under the same conditions employed to obtain high resolution NMR spectra of pure liquids and solutions of low molecular weight molecules (see chapters 1 and 4). Even rubbery, crosslinked polymers, which are completely prevented from flowing by their three-dimensional network structures, produce high-resolution spectra under these same conditions. These observations are the direct consequence of rapid, isotropic motions of the polymer segments. 

In addition to our desire to gain comparable structural information concerning the molecular architectures of intractable polymer solids, which can neither be dissolved or melted, polymer scientists are also interested in learning about the organization and mobility (see chapter 6) of polymer chains in their various solid phases, because of their intimate connections to the unique and useful physical properties they often manifest. The ability to 

Generally two types of experiments can produce high-resolution NMR spectra for polymer solids, depending on the type of nucleus under observation. Abundant spin 1/2 nuclei, such as and may be observed at high resolution in solids by NMR as described in chapter 7. Here, we deal exclusively with spin 1/2 nuclei, such as N, Si, and which are dilute in the solid sample either because of their low natural isotopic abundance ( C, N, Si) or because of their relatively uncommon occurrence in solid polymer samples. Both for its frequent occurrence in synthetic polymers and for the relative ease with which it can be observed, the nucleus at natural abundance (1%) is the specific focus of our discussion. 

---

High resolution solid-state NMR studies of polymer chemical and physical structures... 

---