Correlation of structure, mobility, and morphological information in heterogeneous polymer materials by two-dimensional wideline-separation NMR spectroscopy

1992 ◽  
Vol 25 (12) ◽  
pp. 3273-3277 ◽  
Author(s):  
K. Schmidt-Rohr ◽  
J. Clauss ◽  
H. W. Spiess
Keyword(s):  
Nmr Spectroscopy ◽  
Polymer Materials ◽  
Two Dimensional ◽  
Heterogeneous Polymer

scholarly journals Heterogeneous Polymer Dynamics Explored Using Static 1H NMR Spectra

2020 ◽  
Vol 21 (15) ◽  
pp. 5176
Author(s):  
Todd M. Alam ◽  
Joshua P. Allers ◽  
Brad H. Jones
Keyword(s):  
Nmr Spectroscopy ◽  
1H Nmr ◽  
Dipolar Coupling ◽  
Polymer Materials ◽  
Dynamic Heterogeneity ◽  
Proton Proton ◽  
Dynamic Correlation ◽  
Thermosetting Polymers ◽  
Heterogeneous Polymer ◽  
The Impact

NMR spectroscopy continues to provide important molecular level details of dynamics in different polymer materials, ranging from rubbers to highly crosslinked composites. It has been argued that thermoset polymers containing dynamic and chemical heterogeneities can be fully cured at temperatures well below the final glass transition temperature (Tg). In this paper, we described the use of static solid-state 1H NMR spectroscopy to measure the activation of different chain dynamics as a function of temperature. Near Tg, increasing polymer segmental chain fluctuations lead to dynamic averaging of the local homonuclear proton-proton (1H-1H) dipolar couplings, as reflected in the reduction of the NMR line shape second moment (M2) when motions are faster than the magnitude of the dipolar coupling. In general, for polymer systems, distributions in the dynamic correlation times are commonly expected. To help identify the limitations and pitfalls of M2 analyses, the impact of activation energy or, equivalently, correlation time distributions, on the analysis of 1H NMR M2 temperature variations is explored. It is shown by using normalized reference curves that the distributions in dynamic activation energies can be measured from the M2 temperature behavior. An example of the M2 analysis for a series of thermosetting polymers with systematically varied dynamic heterogeneity is presented and discussed.

Two-dimensional NMR spectroscopy in Earth’s magnetic field

2006 ◽  
Vol 182 (2) ◽  
pp. 343-347 ◽  
Author(s):  
Jeremy N. Robinson ◽  
Andrew Coy ◽  
Robin Dykstra ◽  
Craig D. Eccles ◽  
Mark W. Hunter ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Nmr Spectroscopy ◽  
Two Dimensional ◽  
Earth’S Magnetic Field ◽  
Earth's Magnetic Field

Pulsed Field Gradient Selection in Two-Dimensional Magic Angle Spinning NMR Spectroscopy of Dipolar Solids

1998 ◽  
Vol 134 (2) ◽  
pp. 355-359 ◽  
Author(s):  
Tilo Fritzhanns ◽  
Siegfried Hafner ◽  
Dan E. Demco ◽  
Hans W. Spiess ◽  
Frank H. Laukien
Keyword(s):  
Nmr Spectroscopy ◽  
Field Gradient ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
Two Dimensional ◽  
Pulsed Field ◽  
Angle Spinning

ChemInform Abstract: Two-Dimensional NMR Spectroscopy: Background and Overview of the Experiments

ChemInform ◽  
1988 ◽  
Vol 19 (28) ◽  
Author(s):  
H. KESSLER ◽  
M. GEHRKE ◽  
C. GRIESINGER
Keyword(s):  
Nmr Spectroscopy ◽  
Two Dimensional

Conformation of deltorphin-II in membrane environment studied by two-dimensional NMR spectroscopy and molecular dynamics calculations

1993 ◽  
Vol 212 (1) ◽  
pp. 185-191 ◽  
Author(s):  
Yasunori OHNO ◽  
Motozumi SEGAWA ◽  
Hirofumi OHISHI ◽  
Mitsunobu DOI ◽  
Kunihiro KITAMURA ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Nmr Spectroscopy ◽  
Two Dimensional ◽  
Molecular Dynamics Calculations ◽  
Deltorphin Ii

scholarly journals Structure of scuterivulactone D determined by two-dimensional NMR spectroscopy. A new diterpenoid from a chinese crude drug "Ban Zhi Lian" (Scutellaria rivularis Wall.).

1987 ◽  
Vol 35 (4) ◽  
pp. 1656-1659 ◽  
Author(s):  
Haruhisa Kizu ◽  
Yoshitaka Imoto ◽  
Tsuyoshi Tomimori ◽  
Koji Tsubono ◽  
Shigetoshi Kadota ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Two Dimensional ◽  
Crude Drug
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