High Double Bond Content of Polyisoprene Synthesis via Cationic Polymerization Synergistically Catalyzed by Tf2NH-Ionic Liquids

2021 ◽  
Author(s):  
Guangqian Zhu ◽  
Liang Wang ◽  
Jia Kuang ◽  
Guangqiang Xu ◽  
Yongqiang Zhang ◽  
...  
Keyword(s):  
Ionic Liquids ◽  
Double Bond ◽  
Cationic Polymerization ◽  
Double Bond Content

Thermodynamic validation of double bond comprised ionic liquids for CO2 capture

2019 ◽  
Vol 7 (1) ◽  
pp. 102774 ◽  
Author(s):  
Yuan Wang ◽  
Cailv Zheng ◽  
Yilin Wang ◽  
Hanxiang Chen ◽  
Yun Xu
Keyword(s):  
Ionic Liquids ◽  
Double Bond ◽  
Co2 Capture

scholarly journals Single-chain polybutadiene organometallic nanoparticles: an experimental and theoretical study

2016 ◽  
Vol 7 (3) ◽  
pp. 1773-1778 ◽  
Author(s):  
Inbal Berkovich ◽  
Sudheendran Mavila ◽  
Olga Iliashevsky ◽  
Sebastian Kozuch ◽  
N. Gabriel Lemcoff
Keyword(s):  
Molecular Weight ◽  
Double Bond ◽  
High Molecular Weight ◽  
Metal Binding ◽  
Theoretical Study ◽  
Binding Kinetics ◽  
Rhodium Complexes ◽  
Single Chain ◽  
Double Bond Content

High molecular weight polybutadienes and rhodium complexes were used to produce single chain organometallic nanoparticles. A relationship was found between the cis double bond content of the polymer and metal binding kinetics.

Ultrafast and green ionic liquid-mediated controlled cationic polymerization towards amphiphilic diblock copolymers

2021 ◽  
Author(s):  
Devendra Kumar ◽  
Sk Arif Mohammad ◽  
Md Mehboob Alam ◽  
Sanjib Banerjee
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Ambient Temperature ◽  
Cationic Polymerization ◽  
Diblock Copolymers ◽  
Polymerization Reaction ◽  
Amphiphilic Diblock Copolymers

Ionic liquids (ILs) have gained lot of interest in recent years for use as solvents in organic transformation/polymerization reaction. However, gaining control over ambient temperature polymerization would expand the utility...

The Vulcanization of Highly Elastic Polymers. 81. Sulfur Vulcanization of Ethylene-Propylene Terpolymers Containing Varying Amounts of Double Bonds

1975 ◽  
Vol 48 (5) ◽  
pp. 889-895
Author(s):  
W. Scheele ◽  
S. Fleige
Keyword(s):  
Double Bond ◽  
Supermolecular Structure ◽  
Stoichiometric Ratio ◽  
Technological Properties ◽  
Sulfur Concentration ◽  
Double Bonds ◽  
Ethylene Propylene ◽  
Rate Laws ◽  
Chemical Constitution ◽  
Double Bond Content

Abstract The results of unaccelerated and accelerated vulcanizations of ethylene-propylene terpolymers (EPDM) demonstrate that the reaction of sulfur with allyl systems (such as those which the 1,5-polyenes contain at concentrations far exceeding the quantity of sulfur introduced for crosslinking purposes) tends toward an order above unity and eventually towards second order, as the sulfur concentration and the double bond content approach the stoichiometric ratio. This could be shown with unaccelerated vulcanizations of EPDM in the absence of ZnO, as well as those accelerated by zinc mercaptobenzothiazole. This is so, in our opinion, because in the one case autocatalysis by the polysulfidic sulfur is inhibited, and in the other it becomes negligible because of the very rapid reaction rate. According to Scheele and Huischen, the reaction order for sulfur decrease for the unaccelerated vulcanization of nitrile rubber is first order, both with respect to time and (very important!) with respect to concentration (nt=no=1), and the reaction is not subject to autocatalysis because of disulfidic crosslinks. Accordingly, we arrive at the conviction, in view of the relations obtained with the EPDM rubbers, that all the rate laws determined for sulfur decrease in 1,5-polyene vulcanizations with an excess of double bonds have as their basis pseudo-reaction orders or pseudo-molecularities. In spite of these generally revealing differences in the kinetics of sulfur decrease and in its chemistry between the 1,5-polyenes with their excess of double bonds and the EPDM rubbers with double bond content that is commensurate with the sulfur concentration, the fact still remains that the reaction of sulfur with polymers containing allyl groups has all the characteristics of a multistep reaction of of catalysis by an intermediate and that these characteristics are obviously those generally found in reactions between sulfur and any kind of compound that contains allyl groups. Even the great differences observed between the chemical constitution and the macromolecular structure of the various homo- and copolymers of the 1,3-dienes (natural rubber and poly butadiene), of polypentenamer, and of the EPDM rubbers under consideration here, cannot alter that circumstance, since each situation involves an analogous reaction of sulfur with the allyl units which sulfur-crosslinkable rubbers contain. Any quantitative differences noted can be attributed to the concentration ratios of all the participating reactants as well as the chemical constitution and reactivity of the allyl units. Thus one cannot escape the conclusion that the submolecular, molecular, and supermolecular structure of the rubbers, as well as the polymerization degree and the molecular weight distribution, are of greater importance for the physical, mechanical, and technological properties of the vulcanizates than the vulcanization itself, which, incidentally, should always be carried out so as to realize optimum technological properties in order to meet the industrial technological requirements.

Double bond content of phospholipids and lipid peroxidation negatively correlate with maximum longevity in the heart of mammals

2000 ◽  
Vol 112 (3) ◽  
pp. 169-183 ◽  
Author(s):  
R. Pamplona ◽  
M. Portero-Otı́n ◽  
C. Ruiz ◽  
R. Gredilla ◽  
A. Herrero ◽  
...  
Keyword(s):  
Lipid Peroxidation ◽  
Double Bond ◽  
Maximum Longevity ◽  
Double Bond Content
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