Solid-state nuclear magnetic spectroscopy

In the following, some examples of applications of Fourier transform infrared (FTIR) Spectroscopy and of solid-state nuclear magnetic resonance (NMR) to the study of polymorphism in polymers are described. 

Solid-state nuclear magnetic resonance spectroscopy (SSNMR) [13]... 

Crosslinked polymer networks formed from multifunctional acrylates are completely insoluble. Consequently, solid-state nuclear magnetic resonance (NMR) spectroscopy becomes an attractive method to determine the degree of crosslinking of such polymers (1-4). Solid-state NMR spectroscopy has been used to study the homopolymerization kinetics of various diacrylates and to distinguish between constrained and unconstrained, or unreacted double bonds in polymers (5,6). Solid-state NMR techniques can also be used to determine the domain sizes of different polymer phases and to determine the presence of microgels within a poly multiacrylate sample (7). The results of solid-state NMR experiments have also been correlated to dynamic mechanical analysis measurements of the glass transition (1,8,9) of various polydiacrylates. 

Direct analysis 7.1 XRD, XRF, infrared spectroscopy (NIR and MIR), solid-state nuclear magnetic resonance (NMR), advanced spectroscopy using synchrotron radiation, neutron activation, fluorescence, and visible and electron microscopy... 

Hoh, K.P., Ishida, H. and Koenig, J.L. (1990). Silicon-29 solid state nuclear magnetic resonance spectroscopy of composite interfaces. Polym. Composites 11, 121 125. 

Kinetic gelation models [178] have been used to determine, within experimental error, the fraction of constrained and unconstrained double bonds over a wide range of conversions in the polymerization of ethylene glycol dimethacrylate. The amount of unconstrained and constrained functional groups was determined experimentally by solid state nuclear magnetic resonance spectroscopy. The rules for determining constraint in the model were that all pendant double bonds and all monomers in pools of six or less are constrained. Monomers in pools of seven or more are assumed to be unconstrained. Whether a site is constrained or not does not affect the reactivity only the analysis of the model is affected by the rules defining constraint. 

SOLID STATE NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY (MAS NMR)... 

Byrn SE, Bugay DE, Tishmack PA. Solid state nuclear magnetic resonance spectroscopy—pharmaceutical applications. J Pharm Sci 2003 92(3) 441-474. 

It is useful to emphasise from the outset that alternative techniques for investigating solid samples, other than NMR spectroscopy of the quadrupolar halogen nuclei, tend to be considered first this is likely due to the (perceived) difficulty of the technique and may be related to the issues of sensitivity and line broadening mentioned above. However, the information gained is often complementary, and hence solid state nuclear magnetic resonance (SS NMR) spectroscopy is primarily used when it can provide unique insight unavailable with other techniques. 

For the investigation of the molecular dynamics in polymers, deuteron solid-state nuclear magnetic resonance (2D-NMR) spectroscopy has been shown to be a powerful method [1]. In the field of viscoelastic polymers, segmental dynamics of poly(urethanes) has been studied intensively by 2D-NMR [78, 79]. In addition to ID NMR spectroscopy, 2D NMR exchange spectroscopy was used to extend the time scale of molecular dynamics up to the order of milliseconds or even seconds. In combination with line-shape simulation, this technique allows one to obtain correlation times and correlation-time distributions of the molecular mobility as well as detailed information about the geometry of the motional process [1]. 

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