Line shape analysis, polymer

Solid state materials have been studied by nuclear magnetic resonance methods over 30 years. In 1953 Wilson and Pake ) carried out a line shape analysis of a partially crystalline polymer. They noted a spectrum consisting of superimposed broad and narrow lines which they ascribed to rigid crystalline and amorphous material respectively. More recently several books and large articles have reviewed the tremendous developments in this field, particularly including those of McBrierty and Douglas 2) and the Faraday Symposium (1978)3) —on which this introduction is largely based. 

Bodor, G. X-ray Line Shape Analysis. A. Means for the Characterization of Crystalline Polymers. Vol. 67, pp. 165-194. 

Figure 64 presents the results of the line-shape analysis for c = 0.18 and c = 0.45. In the first case the polymer relaxation is still determined by the Zimm modes at larger Q-values, while at smaller Q the Rouse modes become dominant. Qualitatively, this behavior is expected for the crossover from unscreened Zimm to enhanced Rouse relaxation. At c = 0.45 the Q-dependence P is... 

In the solid, dynamics occurring within the kHz frequency scale can be examined by line-shape analysis of 2H or 13C (or 15N) NMR spectra by respective quadrupolar and CSA interactions, isotropic peaks16,59-62 or dipolar couplings based on dipolar chemical shift correlation experiments.63-65 In the former, tyrosine or phenylalanine dynamics of Leu-enkephalin are examined at frequencies of 103-104 Hz by 2H NMR of deuterated samples and at 1.3 x 102 Hz by 13C CPMAS, respectively.60-62 In the latter, dipolar interactions between the 1H-1H and 1H-13C (or 3H-15N) pairs are determined by a 2D-MAS SLF technique such as wide-line separation (WISE)63 and dipolar chemical shift separation (DIP-SHIFT)64,65 or Lee-Goldburg CP (LGCP) NMR,66 respectively. In the WISE experiment, the XH wide-line spectrum of the blend polymers consists of a rather featureless superposition of components with different dipolar widths which can be separated in the second frequency dimension and related to structural units according to their 13C chemical shifts.63... 

In an attempt to investigate the phase structure of this sample, the line shape analysis of the CH2 resonance line in the DD/MAS spectrum at 87 °C that is shown in Fig. 25 was examined. The result is shown in Fig. 26-(a). The elementary line shape of the crystalline phase was obtained as the line shape of the longest Tic component by Torchia s pulse sequence [53]. It was a doublet and was represented approximately by two down- and upheld Lorentzians with an intensity ration of 2 1 (Spectrum A shown by dotted line in Fig. 26). Since all methylene carbons in the a-crystalline form of this polymer are equivalent in the intramolecular helical conformation, the origin of the doublet could be attrib-... 

Block, H. The Nature and Application of Electrical Phenomena in Polymers. Vol. 33, pp. 93-167. Bodor, G. X-ray Line Shape Analysis. A. Means for the Characterization of Crystalline Polymers. Vol. 67, pp. 165-194,... 

B Schneider, D Doskocilova, JJ Dybal. Motional restrictions and chain conformation in various swollen crosslinked polystyrene gels from 1H NMR line-shape analysis. J Polymer 26 253-259, 1985. 

Relaxation, CIDNP, and N.Q.R.—Relaxation. Phosphorus-31 and carbon-13 relaxation times are reported for dimethyl methylphosphonate. The mobility of phosphazene polymers has been studied using P spin-lattice relaxation parameters. The structure and mobility of polycrystalline nitrilotrimethylphos-phonic acid was estimated by line shape analysis. Molecular interactions of guanosine monophosphate and ATP have been studied through their relaxation properties. ... 

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