The Nature of Secondary Relaxations: The Case of Poly(ethylene-alt-propylene) Studied by Dielectric and Deuteron NMR Spectroscopy

2017 ◽  
Vol 50 (4) ◽  
pp. 1554-1568 ◽  
Author(s):  
Thomas Körber ◽  
Fathia Mohamed ◽  
Marius Hofmann ◽  
Anne Lichtinger ◽  
Lutz Willner ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Secondary Relaxations ◽  
Poly Ethylene ◽  
Deuteron Nmr

Dynamics of hydroxyl deuterons and bonded water molecules in NaDY(0.8) zeolite as studied by means of deuteron NMR spectroscopy and relaxation

2010 ◽  
Vol 37 (3-4) ◽  
pp. 91-100 ◽  
Author(s):  
Z.T. Lalowicz ◽  
G. Stoch ◽  
A. Birczyński ◽  
M. Punkkinen ◽  
M. Krzystyniak ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Water Molecules ◽  
Deuteron Nmr

scholarly journals Synthesis of Mono- and Dithiols of Tetraethylene Glycol and Poly(ethylene glycol)s via Enzyme Catalysis

Catalysts ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 228 ◽  
Author(s):  
Prajakatta Mulay ◽  
Gayatri Shrikhande ◽  
Judit Puskas
Keyword(s):  
Nmr Spectroscopy ◽  
Ethylene Glycol ◽  
1H Nmr ◽  
Enzyme Catalysis ◽  
1H Nmr Spectroscopy ◽  
13C Nmr Spectroscopy ◽  
Tetraethylene Glycol ◽  
Candida Antarctica Lipase ◽  
Poly Ethylene Glycol ◽  
Poly Ethylene

This paper investigates the transesterification of methyl 3-mercaptopropionate (MP-SH) with tetraethylene glycol (TEG) and poly(ethylene glycol)s (PEG)s catalyzed by Candida antarctica Lipase B (CALB) without the use of solvent (in bulk). The progress of the reactions was monitored by 1H-NMR spectroscopy. We found that the reactions proceeded in a step-wise manner, first producing monothiols. TEG-monothiol was obtained in 15 min, while conversion to dithiol took 8 h. Monothiols from PEGs with Mn = 1000 and 2050 g/mol were obtained in 8 and 16 h, respectively. MALDI-ToF mass spectrometry verified the absence of dithiols. The synthesis of dithiols required additional fresh CALB and MP-SH. The structure of the products was confirmed by 1H-NMR and 13C-NMR spectroscopy. Enzyme catalysis was found to be a powerful tool to effectively synthesize thiol-functionalized TEGs and PEGs.

scholarly journals Determination of the degree of randomness in condensation copolymers containing both symmetrical and unsymmetrical monomer units: a theoretical study

e-Polymers ◽  
2003 ◽  
Vol 3 (1) ◽  
Author(s):  
Martine Tessier ◽  
Alain Fradet
Keyword(s):  
Nmr Spectroscopy ◽  
Ethylene Terephthalate ◽  
Functional Group ◽  
Theoretical Study ◽  
Rational Functions ◽  
Poly Ethylene Terephthalate ◽  
Poly Ethylene ◽  
Average Block

Abstract Expressions for the degree of randomness, B, and for the number- and weight-average block lengths of condensation copolymers containing both symmetrical (AA + BB) and unsymmetrical (AB) monomer units are established through an approach based on functional group probabilities. Several parameters introduced in literature to characterize randomness in AA + BB condensation copolymers are also calculated using this approach and compared to B, showing that they are simple linear or rational functions of B. A method for calculating functional group probabilities from the dyad and triad number-fractions determined by NMR spectroscopy is described for poly(ethylene terephthalate)-poly(ε-caprolactone) copolyesters. This method obviously applies to any AA + BB + AB polycondensation and is easily generalizable to other types of condensation copolymers.

Chain dynamics of bilayer n-decylammonium chloride studied by deuteron NMR spectroscopy

1991 ◽  
Vol 84 (1) ◽  
pp. 43-49 ◽  
Author(s):  
S. Jurga ◽  
V. Macho ◽  
B. H�ser ◽  
H. W. Spiess
Keyword(s):  
Nmr Spectroscopy ◽  
Chain Dynamics ◽  
Deuteron Nmr
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