scholarly journals Comparative Analysis of Ethylene/Diene Copolymerization and Ethylene/Propylene/Diene Terpolymerization Using Ansa-Zirconocene Catalyst with Alkylaluminum/Borate Activator: The Effect of Conjugated and Nonconjugated Dienes on Catalytic Behavior and Polymer Microstructure

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 2037
Author(s):  
Amjad Ali ◽  
Muhammad Khurram Tufail ◽  
Muhammad Imran Jamil ◽  
Waleed Yaseen ◽  
Nafees Iqbal ◽  
...  
Keyword(s):  
Double Bond ◽  
1H Nmr ◽  
High Efficiency ◽  
Maximum Yield ◽  
Diene Conjugates ◽  
Polymer Microstructure ◽  
Co Catalyst ◽  
Ethylene Propylene ◽  
Nmr Study ◽  
Backbone Structure

The copolymerization of ethylene‒diene conjugates (butadiene (BD), isoprene (IP) and nonconjugates (5-ethylidene-2-norbornene (ENB), vinyl norbornene VNB, 4-vinylcyclohexene (VCH) and 1, 4-hexadiene (HD)), and terpolymerization of ethylene-propylene-diene conjugates (BD, IP) and nonconjugates (ENB, VNB, VCH and HD) using two traditional catalysts of C2-symmetric metallocene—silylene-bridged rac-Me2Si(2-Me-4-Ph-Ind)2ZrCl2 (complex A) and ethylene-bridged rac-Et(Ind)2ZrCl2 (complex B)—with a [Ph3C][B(C6F5)4] borate/TIBA co-catalyst, were intensively studied. Compared to that in the copolymerization of ethylene diene, the catalytic activity was more significant in E/P/diene terpolymerization. We obtained a maximum yield of both metallocene catalysts with conjugated diene between 3.00 × 106 g/molMt h and 5.00 × 106 g/molMt h. ENB had the highest deactivation impact on complex A, and HD had the most substantial deactivation effect on complex B. A 1H NMR study suggests that dienes were incorporated into the co/ter polymers’ backbone through regioselectivity. ENB and VNB, inserted by the edo double bond, left the ethylidene double bond intact, so VCH had an exo double bond. Complex A’s methyl and phenyl groups rendered it structurally stable and exhibited a dihedral angle greater than that of complex B, resulting in 1,2 isoprene insertion higher than 1, 4 isoprene that is usually incapable of polymerization coordination. High efficiency in terms of co- and ter- monomer incorporation with higher molecular weight was found for complex 1. The rate of incorporation of ethylene and propylene in the terpolymer backbone structure may also be altered by the conjugated and nonconjugated dienes. 13C-NMR, 1H-NMR, and GPC techniques were used to characterize the polymers obtained.

Stereochemistry of some substituted 2-furyl- and 2-thienyl ethylene derivatives. 1H NMR study

1982 ◽  
Vol 47 (12) ◽  
pp. 3412-3417 ◽  
Author(s):  
Miloslava Dandárová ◽  
Jaroslav Kováč ◽  
Daniel Végh ◽  
Vladimír Žvak
Keyword(s):  
Double Bond ◽  
Nmr Spectroscopy ◽  
1H Nmr ◽  
Side Chain ◽  
H Nmr ◽  
Nmr Study ◽  
Thiophene Derivatives

Stereochemistry of (E)- and (Z)-1-(5-nitro-2-furyl)-2-Y-ethylenes and 1-(5-nitro-2-thienyl)-2-Y-ethylenes (where Y = CH3O, 4-CH3C6H4O, N3 and Br) and of E and Z isomers of methyl 2-methyl-3-(2-furyl)propenoate and methyl 2-methyl-3-(2-thienyl)propenoate was studied by 1H NMR spectroscopy. With 1-(5-nitro-2-furyl)-2-Y-ethylenes, it was found that the preferred conformation of the furyl substituent relative to the side chain double bond is s-trans in the E isomers and s-cis in the Z isomers. The s-cis conformation is prevailing in both isomers of methyl 2-methyl-3-(2-furyl)propenoate. The E and Z isomers of all studied thiophene derivatives exist in the s-trans conformation.

Dynamic 1H-NMR study of unusually high barrier to rotation about the partial C N double bond in N,N-dimethyl carbamoyl 5-aryloxytetrazoles

2017 ◽  
Vol 1133 ◽  
pp. 244-252 ◽  
Author(s):  
Fahimeh Movahedifar ◽  
Ali Reza Modarresi-Alam ◽  
Erich Kleinpeter ◽  
Uwe Schilde
Keyword(s):  
Double Bond ◽  
1H Nmr ◽  
Nmr Study ◽  
Dynamic 1H Nmr

Dynamic 1H NMR study around the heteroaryl–carbon and carbon–carbon single bonds and also around carbon–carbon double bond in a particular phosphorous ylide involving a 2-methyl indole

2009 ◽  
Vol 50 (26) ◽  
pp. 3621-3624 ◽  
Author(s):  
Sayyed Mostafa Habibi-Khorassani ◽  
Malek Taher Maghsoodlou ◽  
Ali Ebrahimi ◽  
Fatemeh Vasheghani Farahani ◽  
Elahe Mosaddeg ◽  
...  
Keyword(s):  
Double Bond ◽  
1H Nmr ◽  
Carbon Double Bond ◽  
Nmr Study ◽  
Dynamic 1H Nmr ◽  
Single Bonds

1H-NMR study of Mott insulator κ -(ET)2Cu2(CN)3with isotropic triangular lattice

2004 ◽  
Vol 114 ◽  
pp. 377-378 ◽  
Author(s):  
Y. Shimizu ◽  
K. Miyagawa ◽  
K. Oda ◽  
K. Kanoda ◽  
M. Maesato ◽  
...  
Keyword(s):  
1H Nmr ◽  
Triangular Lattice ◽  
Mott Insulator ◽  
Nmr Study
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