NMR Studies of Motion in Solid Polymer Systems at High Pressure
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We investigate the effect of high pressure on the molecular order and the dynamics of solid (crystalline and amorphous) systems of simple synthetic polymers. Pulsed deuteron-NMR techniques1,2 are used to study the effect of high hydrostatic pressure on the dynamical properties of polystyrene (PS), polycarbonate (PC) and polyethene (PE). Type and time-scale of the motion of polymer chain segments and side groups are studied from the 2H-spin-lattice relaxation rates and solid echo (SE) and spin-alignment (SA) echo spectra, which are dominated by the deuteron quadrupolar coupling. The aim of the application of high pressure is the distinction between the effects of changes in temperature and in pressure. In particular we investigate the dynamics near phase transitions. This paper is a preliminary account of our results.
KeywordsCorrelation Time High Hydrostatic Pressure Chain Motion Bottom Flange Electric Field Gradient Tensor
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