th  - 1988 - 51st ENC Conference

It
174 I
DESIGN OF A HIGH RESOLUTION HIGH PRESSURE DOUBLE RESONANCE
NMR PROBE: P. J. Grandinetti', D. Vander Velde, C.-L. Xie, N. A. Walker, and
J. Jonas, University of Illinois, Urbana, IL 61801
High pressure NMR studies have demonstrated the importance of pressure in under-
standing molecular dynamics in liquids. We have extended this technique to study
complex disordered systems using double resonance (i.e. x3C{1H}) NMR at pres-
sures from 1 to 4000 bar. The new design minimizes the length of rf transmission
hnes between the sample coil (in the high pressure environment) and the resonant
circuit (in the ambient environment). The sample coil is double-tuned so that large
sample volumes (12 mm diameter) can be used within the pressure vessel for cases
of low sensitivity.
Prehminary results are reported for a study of the pressure effects on the molecular
motion of 2-ethyl hexylbenzoate, a model synthetic elastohydrodynamic lubricant.
175
CARBON-13 CP/MAS NMR STUDY OF THE NYLON-6 POLYMOPHS AND DYNAMICS:
Dehua Wang',Jianzhi Hu, Xin Yan, Guoxi Wan9 and Baogon9 Qian,
Wuhan Institute of Physics, Academia Sinica, Wuhan, Hubei, P.R. China
C-13 CP/MAS spectra of nyton-5 were obtained on MSL-400 instrument.
was foundthat the ~ carbon
has two peaks in
originate from d
in sotution spec
existence of dif
state the = , p
A series o
contact time to
feast square opt
potarization rat
a 15 ~' 5
- [-CO-CH= -CH= -CH= -CH, -CH= -NH-] -. ny t on-6
sotid state. They are designated as ~ = and ~ , which
ifferent crystattine components. The two peaks coatesced
tru= of the same sampte. It 9ires the evidence of co-
ferent crystattine re9ions in sotid nyton-6.In the sotid
eak is 2.2 ppm to upfietd from the ~ • peak.
f CP/MAS spectra of nyton-6 was measured by varyin9 the
investigate the dynamic behavior. A SIMPLEX nontinear
imization at9orithm was apptied to catcutate the cross-
es T,, and the proton T• p . The dynamic parameters of
sotid nyton-6 we re catcutated accordin9 to Ngai formatism.
186