Low-field NMR studies of polymer crystallization kinetics: changes in the melt dynamics

Physikalisches Institut, Albert-Ludwigs-Universität, 79104 Freiburg, Germany
Fachbereich Physik, Martin-Luther-Universität Halle-Wittenberg, 06108 Halle/Saale, Germany

Abstract

The free induction decay in ¹H NMR experiments carried out for crystallizing polymers can be directly decomposed in contributions from crystals, melt-like regions and amorphous regions with a reduced mobility. Here the results of time-dependent experiments conducted with the aid of a cost-efficient low-field NMR instrument are presented, obtained for sPP, PεCL and P(EcO). Crystallization isotherms are compared with those obtained by X-ray scattering and dilatometry. There are some minor systematic deviations which can be explained and accounted for. For all systems a large fraction of amorphous chain parts in regions with a reduced mobility is found.