The Course of Ring Opening of Glycidyl Ethers with Nucleophilic Reagents

1953 ◽  
Vol 75 (20) ◽  
pp. 5002-5006 ◽  
Author(s):  
Gerrit Van Zyl ◽  
George D. Zuidema ◽  
John F. Zack ◽  
Paul B. Kromann
Keyword(s):  
Ring Opening ◽  
Glycidyl Ethers ◽  
Nucleophilic Reagents

A Further Study of the Course of Ring-opening of Unsymmetrical Epoxides with Nucleophilic Reagents

1953 ◽  
Vol 75 (2) ◽  
pp. 294-296 ◽  
Author(s):  
George D. Zuidema ◽  
Paul L. Cook ◽  
Gerrit Van Zyl
Keyword(s):  
Ring Opening ◽  
Nucleophilic Reagents

scholarly journals Ring-opening polymerization of monosubstituted oxiranes in the presence of potassium hydride: determination of initiation course and structure of macromolecules by MALDI-TOF mass spectrometry

2019 ◽  
Vol 26 (12) ◽  
Author(s):  
Zbigniew Grobelny ◽  
Justyna Jurek-Suliga ◽  
Sylwia Golba
Keyword(s):  
Mass Spectrometry ◽  
Ring Opening ◽  
Glycidyl Ether ◽  
Ring Opening Polymerization ◽  
Size Exclusion ◽  
Oxirane Ring ◽  
Maldi Tof ◽  
Glycidyl Ethers ◽  
Initiation Step ◽  
Potassium Hydride

AbstractSeveral monosubstituted oxiranes were polymerized with suspension of potassium hydride (KH) in tetrahydrofuran (THF) at room temperature. This heterogeneous process resulted in polyethers with various starting groups depending on the kind of monomer. The macromolecules formed in ring-opening polymerization of monosubstituted oxiranes were analyzed by Matrix Assisted Laser Desorption/Ionization - Time of Flight Mass Spectrometry (MALDI-TOF MS). It was stated, that initiation of propylene oxide (PO) polymerization with KH proceeded via three ways, i.e. cleavage of oxirane ring in the β-position, monomer deprotonation and deoxygenation. Potassium isopropoxide, potassium allyloxide and potassium hydroxide were the real initiators. The main reactions, which occur in the initiation step, depend on the type of monomer used. In the case of allyl glycidyl ether (AGE) and phenyl glycidyl ether (PGE) deprotonation of the monomer did not occur. During initiation of glycidyl ethers oxirane ring was opened and also linear ether bond between glycidyl group and oxygen atom was cleaved under influence of KH. Interestingly, formation of new kinds of macromolecules was observed in the systems containing glycidyl ethers, which do not possess mers of the monomers used. Mechanisms of the studied processes were presented and discussed. Carbon-13 Nuclear Magnetic Resonance (13C NMR) was used as supporting technique for analysis of the obtained polymers. Number average molar masses of the polymers (Mn) determined by Size Exclusion Chromatography (SEC) were about two times higher than calculated ones. It indicated that half of used KH did not take part in the initiation step.

The reactions of isothiazolium salts with selected nucleophilic reagents. The preparation of thieno[2,3-c]isothiazolium salts

1977 ◽  
Vol 55 (7) ◽  
pp. 1123-1128 ◽  
Author(s):  
David M. McKinnon ◽  
Mohammed E. R. Hassan ◽  
Mohinder Chauhan
Keyword(s):  
Ring Opening ◽  
Nucleophilic Attack ◽  
Isothiazolium Salts ◽  
Thiophene Derivatives ◽  
Nucleophilic Reagents

Isothiazolium salts react with a number of carbanions by attack on sulfur. Thiophene derivatives, formed by ring opening and recyclization, are often products but with cyclopentadiene, pseudoazulene products are obtained. 3-Amino-2-acylthiophenes, prepared by suitable nucleophilic attack, are synthetic precursors of thieno[2,3-c]isothiazolium salts

Ring opening reactions in glycidyl ethers by squaric acid and additives

2005 ◽  
Vol 24 (6) ◽  
pp. 810-812 ◽  
Author(s):  
Iv. Glavchev ◽  
Ch. Yordanova ◽  
M. Ivanova
Keyword(s):  
Ring Opening ◽  
Squaric Acid ◽  
Glycidyl Ethers ◽  
Ring Opening Reactions

scholarly journals Oxidation Level and Glycidyl Ether Structure Determine Thermal Processability and Thermomechanical Properties of Arabinoxylan-Derived Thermoplastics

2020 ◽  
Author(s):  
Parveen Kumar Deralia ◽  
Aline Maire du Poset ◽  
Anja Lund ◽  
Anette Larsson ◽  
Anna Ström ◽  
...  
Keyword(s):  
Thermal Processing ◽  
Ring Opening ◽  
Glycidyl Ether ◽  
Thermomechanical Properties ◽  
Subsequent Reduction ◽  
Glycidyl Ethers ◽  
Dramatic Difference ◽  
Molar Substitution ◽  
Relationship Of ◽  
The Relationship

Herein we present arabinoxylan (AX)-based thermoplastics obtained by ring opening oxidation and subsequent reduction (dA-AX) combined with hydrophobization with three different glycidyl ethers [n-butyl (BuGE), isopropyl (iPrGE) and 2-ethylhexyl (EtHGE) glycidyl ether]. We also present the relationship of structural composition, thermal processing and thermomechanical properties. The BuGE and iPrGE etherified dA-AXs showed glass transition temperatures (T<sub>g</sub>) far below their degradation temperatures and gave thermoplastic materials when compression-molded at 140˚C. The BuGE (3 mole) etherified dA-AX films at 19 and 31 % oxidation levels exclusively exhibit 244 % (±42) and 267 % (±72) elongation. In contrast, iPrGE-dA-AX samples with shorter and branched terminals in the side chains had maximum 60 % (±19) elongation. The dramatic difference in elongation is assumed to be due to the presence of longer alkoxide chains, higher molar substitution and dual T<sub>g</sub> for the BuGE samples. Such superior elongation of AX thermoplastic films and its relationship with molar substitution and T<sub>g</sub> has not been reported before.

Polymerization of long chain alkyl glycidyl ethers: a platform for micellar gels with tailor-made melting points

2018 ◽  
Vol 9 (44) ◽  
pp. 5327-5338 ◽  
Author(s):  
Patrick Verkoyen ◽  
Tobias Johann ◽  
Jan Blankenburg ◽  
Christian Czysch ◽  
Holger Frey
Keyword(s):  
Block Copolymers ◽  
Ring Opening ◽  
Amphiphilic Block Copolymers ◽  
Melting Points ◽  
Controlled Polymerization ◽  
Glycidyl Ethers ◽  
Anionic Ring ◽  
Long Chain

Controlled polymerization of long-chain alkyl glycidyl ethers (AlkGE) under anionic ring opening conditions is enabled by the addition of 18-crown-6. Capitalizing on this strategy, highly amphiphilic block copolymers are prepared that form hydrogels with adjustable melting points.

Synthesis of Well-Defined Amphiphilic Star-Block and Miktoarm Star Copolyethers via t-Bu-P4-Catalyzed Ring-Opening Polymerization of Glycidyl Ethers

2016 ◽  
Vol 49 (2) ◽  
pp. 499-509 ◽  
Author(s):  
Yusuke Satoh ◽  
Kana Miyachi ◽  
Hirohiko Matsuno ◽  
Takuya Isono ◽  
Kenji Tajima ◽  
...  
Keyword(s):  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Glycidyl Ethers ◽  
Miktoarm Star
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