Alternating Copolymerization of Arylallenes with Carbon Monoxide Catalyzed by a π-Allylrhodium Complex. Synthesis of New Polyketones with Regulated Structure and Molecular Weight

1998 ◽  
Vol 31 (25) ◽  
pp. 8731-8736 ◽  
Author(s):  
Jun-chul Choi ◽  
Isao Yamaguchi ◽  
Kohtaro Osakada ◽  
Takakazu Yamamoto
Keyword(s):  
Molecular Weight ◽  
Carbon Monoxide ◽  
Alternating Copolymerization

Studies on Influencing Factors of Polyketone Molecular Weight by Palladium Catalyzed Alternating Copolymerization with Carbon Monoxide and Ethylene

2013 ◽  
Vol 634-638 ◽  
pp. 2014-2018
Author(s):  
Jia Yao Du ◽  
Liang Chen ◽  
Wen Wei ◽  
Lin Deng ◽  
Ling Gao ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Carbon Monoxide ◽  
Water Content ◽  
Temperature Rise ◽  
Palladium Catalyzed ◽  
System Temperature ◽  
Main Factors ◽  
Increasing Temperature ◽  
Alternating Copolymerization ◽  
Strong Acids

With Pd(AcO)2DPPP as catalytic precursor of CO/C2H4 alternating copolymerization. The main factors which affect the molecular weight of polyketone were studied. The results showed that: Temperature was the most important factor in copolymerization. The polyketone molecular weight lower faster with increasing temperature, have a decrease of 53% when system temperature rise from 70°C to 80°C, and the palladium-catalyzed progenitor easy to decomposition and become deactivation. Adding pressure was in favor of the increase of copolymerization rate and molecular weight. Water content in methanol solvent was sensitive to copolymerization rate, as far as molecular weight was concerned, it made no difference. HClO4 and other strong acids in the catalytic system will help improve the molecular weight of the polyketone.

scholarly journals A METHOD FOR THE DETERMINATION OF DIFFUSION CONSTANTS AND THE CALCULATION OF THE RADIUS AND WEIGHT OF THE HEMOGLOBIN MOLECULE

1929 ◽  
Vol 12 (4) ◽  
pp. 543-554 ◽  
Author(s):  
John H. Northrop ◽  
M. L. Anson
Keyword(s):  
Molecular Weight ◽  
Carbon Monoxide ◽  
Diffusion Coefficient ◽  
Porous Membrane ◽  
Diffusion Constants ◽  
Einstein's Equation ◽  
Hemoglobin Molecule

A method is described for determining the diffusion coefficient of solutes by determining the rate of passage of the solute through a thin porous membrane between two solutions of different concentration. The method has been used to determine the diffusion coefficient of carbon monoxide hemoglobin. This was found to be 0.0420 ± 0.0005 cm.2 per day at 5°C. The molecular weight of carbon monoxide hemoglobin calculated by means of Einstein's equation from this quantity is 68,600 ± 1,000.

The Alternating Copolymerization of Epoxides and Carbon Monoxide: A Novel Way to Polyesters

2003 ◽  
pp. 114-130 ◽  
Author(s):  
Markus Allmendinger ◽  
Robert Eberhardt ◽  
Gerrit A. Luinstra ◽  
Ferenc Molnar ◽  
Bernhard Rieger
Keyword(s):  
Carbon Monoxide ◽  
Alternating Copolymerization
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