NMR Analysis of Polyester Urethane End Groups and Solid-Phase Hydrolysis Kinetics

2000 ◽  
Vol 33 (10) ◽  
pp. 3569-3576 ◽  
Author(s):  
David M. LeMaster ◽  
Griselda Hernández
Keyword(s):  
Solid Phase ◽  
Hydrolysis Kinetics ◽  
Nmr Analysis ◽  
Polyester Urethane ◽  
End Groups

scholarly journals A New Insight into the Comonomer Effect through NMR Analysis in Metallocene Catalysed Propene–co–1-Nonene Copolymers

Polymers ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1266
Author(s):  
Qiong Wu ◽  
Alberto García-Peñas ◽  
Rosa Barranco-García ◽  
María Luisa Cerrada ◽  
Rosario Benavente ◽  
...  
Keyword(s):  
Active Sites ◽  
Nmr Analysis ◽  
Reaction Parameters ◽  
Transfer Processes ◽  
Detailed Explanation ◽  
Selective Interaction ◽  
End Groups ◽  
Alpha Olefin ◽  
Kinetic Phenomenon ◽  
Insight Into

The “comonomer effect” is an intriguing kinetic phenomenon in olefin copolymerization that still remains without a detailed explanation. It typically relates to the rate of enhancement undergone in ethylene and propene catalytic polymerization just by adding small fractions of an alpha-olefin. The difficulty lies in the fact that changes caused by the presence of the comonomer in reaction parameters are so conspicuous that it is really difficult to pin down which of them is the primary cause and which ones are side factors with marginal contribution to the phenomenon. Recent investigations point to the modification of the catalyst active sites as the main driving factor. In this work, the comonomer effect in the metallocene copolymerization of propene and 1-nonene is analysed and correlated to the comonomer role in the termination of the chain-growing process. The associated termination mechanisms involved furnish most of chain-free active sites, in which the selective interaction of the comonomer was proposed to trigger the insertion of monomers. A thorough characterisation of chain-end groups by means of the 1H NMR technique allows for detailing of specific transfer processes, ascribed to comonomer insertions, as well as evidencing the influence of the growing chain’s microstructure over the different termination processes available.

Solid-Phase Synthesis of Potential Molecular Wires. Attachment of Molecular Alligator Clips

1995 ◽  
Vol 413 ◽  
Author(s):  
LeRoy Jones ◽  
James M. Tour
Keyword(s):  
Solid Phase Synthesis ◽  
Solid Phase ◽  
Electronic Devices ◽  
Molecular Wires ◽  
Solution Phase ◽  
Molecular Electronic ◽  
Phase Synthesis ◽  
Solution Phase Synthesis ◽  
End Groups ◽  
Convergent Approach

ABSTRACTDescribed is the solid-phase and solution-phase synthesis of oligo(2-dodecylphenyleneethynylene) s via an iterative divergent/convergent approach. Synthesized were the monomer, dimer, tetramer, octamer and 16-mer of the oligo(2-dodecylphenylene-thynylene)s. The synthetic protocol for the synthesis and attachment of protected thiol-containing end groups is also described which may serve as molecular alligator clips for adhesion to gold surfaces. These oligomers may act as molecular wires in molecular electronic devices.

scholarly journals Development of an immunosorbent for solid-phase NMR-based assay

2019 ◽  
Vol 484 (5) ◽  
pp. 637-640
Author(s):  
P. V. Khramtsov ◽  
M. D. Kropaneva ◽  
M. S. Bochkova ◽  
V. P. Timganova ◽  
S. A. Zamorina ◽  
...  
Keyword(s):  
Uniform Distribution ◽  
Solid Phase ◽  
Membrane Thickness ◽  
Nmr Analysis ◽  
Coil Size

The conditions for constructing an immunosorbent reagent for solid-phase NMR analysis were optimized. For this purpose, we increased the area of the sensitized portion of the membrane to fit the relaxometer coil size and added the agent sorption buffer. This provided the penetration of the anti-ligand molecules into the membrane thickness and their uniform distribution.

scholarly journals Liquid Chromatography-Solid Phase Extraction-NMR (LC-SPE-NMR) Analysis of Liquid Crystalline Mixtures

2011 ◽  
Vol 15 (1) ◽  
pp. 14-24
Author(s):  
Gregory Hyung-Jin Park ◽  
Ae-Na Park ◽  
Kyung-Rae Rho ◽  
Jong-Ho Shin ◽  
Yeong-Jeon Kim ◽  
...  
Keyword(s):  
Liquid Chromatography ◽  
Solid Phase Extraction ◽  
Liquid Crystalline ◽  
Solid Phase ◽  
Phase Extraction ◽  
Nmr Analysis

Stereochemistry of living poly(methyl methacrylate) anions as determined by carbon-13 NMR analysis of carbon-13-labeled methyl end groups

1992 ◽  
Vol 25 (13) ◽  
pp. 3553-3560 ◽  
Author(s):  
Raymond Volpe ◽  
Thieo E. Hogen-Esch ◽  
Friedhelm Gores ◽  
Axel H. E. Mueller
Keyword(s):  
Methyl Methacrylate ◽  
Nmr Analysis ◽  
Poly Methyl Methacrylate ◽  
End Groups

Solid-Phase Glycosylation of Peptide Templates and On-Bead MAS-NMR Analysis: Perspectives for Glycopeptide Libraries

2001 ◽  
Vol 7 (16) ◽  
pp. 3584 ◽  
Author(s):  
Koen M. Halkes ◽  
Charlotte H. Gotfredsen ◽  
Morten Grøtli ◽  
Les P. Miranda ◽  
Jens Ø. Duus ◽  
...  
Keyword(s):  
Solid Phase ◽  
Mas Nmr ◽  
Nmr Analysis

Carbon-13 NMR analysis of propene-butene copolymer. Steric structure of chain end groups and inhomogeneity of isotactic sites

1990 ◽  
Vol 23 (8) ◽  
pp. 2406-2409 ◽  
Author(s):  
P. Locatelli ◽  
M. C. Sacchi ◽  
I. Tritto ◽  
F. Forlini
Keyword(s):  
Steric Structure ◽  
Nmr Analysis ◽  
End Groups

scholarly journals NMR Analysis of Hydroxyl-Terminated Polybutadiene End Groups and Reactivity Differences with Monoisocyanates

2018 ◽  
Vol 56 (23) ◽  
pp. 2665-2671 ◽  
Author(s):  
Timothy S. Haddad ◽  
Levi M. J. Moore ◽  
Josiah T. Reams ◽  
Michael D. Ford ◽  
Jacob C. Marcischak ◽  
...  
Keyword(s):  
Nmr Analysis ◽  
End Groups
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