Nuclear magnetic resonance solid-state effect

M. H. Cohen and F. Reif, Nuclear quadrupole effects in nuclear magnetic resonance. Solid State Phys. 5, 321-438 (1957). 

A study on the effectiveness of the E-plastomers as impact modifiers for iPP was carried out in relation to the traditional modifier EPDM. In this study, the flow properties of the E-plastomer-iPP and EPDM-PP blends were also evaluated. The blends were analyzed by solid-state 13C-nuclear magnetic resonance (NMR) spectroscopy, microscopy (SEM), and DSC. The results showed that E-plastomer-PP and EPDM-PP blends present a similar crystallization behavior, which resulted in a similar mechanical performance of the blends. However, the E-plastomer-PP blend presents lower torque values than the EPDM-PP blend, which indicates a better processibility when E-plastomer is used as an impact modifier for iPP. 

The usefulness of quadrupolar effects on the nuclear magnetic resonance c I 7 yi nuclei in the defect solid state arises from the fact that point defects, dislocations, etc., give rise to electric field gradients, which in cubic ciystals produce a large effect on the nuclear resonance line. In noncubic crystals defects of course produce an effect, but it may be masked by the already present quadrupole interaction. Considerable experimental data have been obtained by Reif (96,97) on the NMR of nuclei in doped, cubic, polycrystalline solids. The effect of defect-producing impurities is quite... 

Nuclear magnetic resonance (NMR) spectroscopy is a most effective and significant method for observing the structure and dynamics of polymer chains both in solution and in the solid state [1]. Undoubtedly the widest application of NMR spectroscopy is in the field of structure determination. The identification of certain atoms or groups in a molecule as well as their position relative to each other can be obtained by one-, two-, and three-dimensional NMR. Of importance to polymerization of vinyl monomers is the orientation of each vinyl monomer unit to the growing chain tacticity. The time scale involved in NMR measurements makes it possible to study certain rate processes, including chemical reaction rates. Other applications are isomerism, internal relaxation, conformational analysis, and tautomerism. 

Smernik, R. J., and Oades, J. M. (2002). Paramagnetic effects on solid state 13C nuclear magnetic resonance spectra of soil organic matter. J. Environ. Qual. 31,414 420. 

Forbes J, Bowers J, Shan X, Moran L, Oldfield E, Moscarello MA, Some new developments in solid-state nuclear magnetic resonance spectroscopic studies of lipids and biological membranes, including the effects of cholesterol in model and natural systems, /. Chem. Soc. Faraday Trans., 84 3821-3849, 1988. 

Below that temperature this thermally activated motion is frozen out. There is a characteristic change in the solid-state lineshape that clearly demonstrates the effect. Nuclear magnetic resonance can in such cases provide important information about molecular structure and dynamics in solids. 

Plasticisers are added to PVC to achieve flexibility and workability. The flexibility or softness is determined by the type of plasticiser and level used in relation to the PVC (phr). They also operate as an internal lubricant between the PVC molecules. Based on organic esters, e.g., phthalates, adipates, trimellitates, phosphates, etc., addition levels can be as low as 20 phr for semi-rigid to 100 phr for very flexible applications. The effect on the thermal stability significantly depends on the physical state of the PVC-plasticiser system (260). The relative amount of crystalline PVC in PVC/diethylhexyl phthalate has been identified on the basis of a combination of carbon-13 solution and solid state nuclear magnetic resonance (NMR) (361). 

Cohen, M. H. and Reif, R (1957). Quadrupole effects in nuclear magnetic resonance studies of solids. In F. Seitz and D. Turnbull, eds. Solid State Physics. Academic Press, New York, p. 321. 

Freude D, Haase J (1993) Qnadrapole effects in solid-state nuclear magnetic resonance. NMR Basic Principles and Progress, 29 1-90... 

Several physical methods have been employed to ascertain the existence and nature of ICs infrared (IR) absorption spectroscopy nuclear magnetic resonance (NMR) spectroscopy,14 including JH nuclear Overhauser effect (NOE) difference spectroscopy, H 2-D rotating-frame Overhauser effect spectroscopy (2-D ROESY),15 and solid-state 13C cross-polarization/magic angle spinning (CP/MAS) spectroscopy 16 induced circular dichroism (ICD) absorption spectroscopy 17 powder and singlecrystal X-ray diffraction 18 and fast atom bombardment mass spectrometry (FAB MS). 

The ultimate molecular level characterization of a pharmaceutical material is performed on the level of individual chemical environments of each atom in the compound, and this information is best obtained using nuclear magnetic resonance (NMR) spectroscopy. Advances in instrumentation and computer pulse sequences currently allow these studies to be carried out routinely in the solid state.2 Although any nucleus that can be studied in the solution phase also can be studied in the solid state, most work has focused on studies. H-NMR remains an extremely difficult measurement in the solid state, and the data obtained from such work can be obtained only at medium resolution. The main problem is that H-NMR has one of the smallest isotropic chemical shift ranges (12 ppm), but has peak broadening effects that can span several parts per million in magnitude. 

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