th  - 1987 - 51st ENC Conference

WF4S
SEGMENTAL DYNAMICS IN NYLON 66 BY DEUTERIUM NMR
Hitoshi Miura* and Alan D. English
Central Research and Development Department
Experimental Station
E. I. Dupont de Nemours & Company
Wilmington, Delaware 19898
The study of chain dynamics of nylon 66 by deuterium
NMR is described. We prepared five selectively deuterated
samples of nylon 66, for which T1 data and quadrupolar echo
powder spectra were obtained at various temperatures from
-I19C to 228C. By using the difference of T1 in the
different phases, we can separate their spectra from each
other. This enables us to study the chain dynamics of each
phase independently.
The motion at different places in the methylene
segments in nylon 66 are quite different and are strongly
dependent upon temperature. Line shape calculations for
several kinds of models of molecular motion are compared to
experimental spectra, which give important information on
the segmental motion of the polymer at various temperatures.
Models of motion in "pinned segments" composed of either
four or six methylene segments in either crystalline or
noncrystalline domains may be examined with this system. We
will present the results and discuss them.