MULTIPLE PULSE NUCLEAR MAGNETIC-RESONANCE OF SOLID POLYMERS - DYNAMICS OF POLY(TETRAFLUOROETHYLENE)

Conventional NMR spectra of rare (13C) or abundant 1H, 19F) spins in unoriented polymers are dominated by dipolar interactions. These dipolar spectra are less sensitive to details of the structure and motion than are chemical shift spectra. Chemical shift spectra of rare spins can be obtained by removing the large heteronuclear dipolar interactions by a high power dipolar decoupling field at the resonant frequency of the abundant spins. Chemical shift spectra of abundant spins can be obtained by removing the homonuclear dipolar interactions with a multiple pulse sequence.1a The rare spin case both with and without magic angle spinning has been used to study motion in solid glassy polymers at room temperature.2 The results reported here are the first example of the use of abundant spin chemical shift spectra to examine the structure and motions of a solid polymer as a function of temperature. © 1979, American Chemical Society. All rights reserved.