Journal
CHEMICAL PHYSICS
Volume 272, Issue 2-3, Pages 199-212Publisher
ELSEVIER SCIENCE BV
DOI: 10.1016/S0301-0104(01)00476-1
Keywords
polymers; chemical synthesis; nuclear resonances
Ask authors/readers for more resources
The helix conformation in helical polycarbodiimides as a function of the side chains were studied by C-13 CP/MAS NMR. From these results, the structures of the all polycarbodiimides were defined, and the C-13 spin-lattice relaxation times in the rotating frame were measured. We discuss the mobility, the correlation time, and the activation energy for each carbon of the polycarbodiimides as a function of the side chains. The activation energies of main-chain carbons are strongly dependent on the side chains. From these results, the activation energies of the main-chain carbons for polycarbodiimides with directly bonded aromatic rings are distinctly different from those for polycarbodiimides with non-bonded aromatic rings. Based on our findings, we know that the polycarbodiimides with directly bonded aromatic rings have high activation energy and high helix reversal barriers. (C) 2001 Published by Elsevier Science B.V.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available