Stereoselective cationic polymerization of vinyl ethers by easily and finely tunable titanium complexes prepared from tartrate-derived diols: isospecific polymerization and recognition of chiral side chains

2020 ◽  
Vol 11 (20) ◽  
pp. 3398-3403 ◽  
Author(s):  
Hironobu Watanabe ◽  
Takuya Yamamoto ◽  
Arihiro Kanazawa ◽  
Sadahito Aoshima
Keyword(s):  
Tartaric Acid ◽  
Vinyl Ether ◽  
Cationic Polymerization ◽  
Side Chains ◽  
Titanium Complexes ◽  
Vinyl Ethers

Isotactic poly(vinyl ether)s were generated by titanium TADDOLates, which can be prepared from naturally abundant tartaric acid in a facile and economical manner with well-defined structures.

scholarly journals Characteristics and Mechanism of Vinyl Ether Cationic Polymerization in Aqueous Media Initiated by Alcohol/B(C6F5)3/Et2O

Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 500
Author(s):  
Jinghan Zhang ◽  
Yibo Wu ◽  
Kaixuan Chen ◽  
Min Zhang ◽  
Liangfa Gong ◽  
...  
Keyword(s):  
Vinyl Ether ◽  
Cationic Polymerization ◽  
Density Functional ◽  
Aqueous Media ◽  
Vinyl Ethers ◽  
Experimental Conditions ◽  
Functional Theory ◽  
Air Atmosphere ◽  
Significant Difference ◽  
First Time

Aqueous cationic polymerizations of vinyl ethers (isobutyl vinyl ether (IBVE), 2-chloroethyl vinyl ether (CEVE), and n-butyl vinyl ether (n-BVE)) were performed for the first time by a CumOH/B(C6F5)3/Et2O initiating system in an air atmosphere. The polymerization proceeded in a reproducible manner through the careful design of experimental conditions (adding initiator, co-solvents, and surfactant or decreasing the reaction temperature), and the polymerization characteristics were systematically tested and compared in the suspension and emulsion. The significant difference with traditional cationic polymerization is that the polymerization rate in aqueous media using B(C6F5)3/Et2O as a co-initiator decreases when the temperature is lowered. The polymerization sites are located on the monomer/water surface. Density functional theory (DFT) was applied to investigate the competition between H2O and alcohol combined with B(C6F5)3 for providing a theoretical basis. The effectiveness of the proposed mechanism for the aqueous cationic polymerization of vinyl ethers using CumOH/B(C6F5)3/Et2O was confirmed.

scholarly journals Polar Thermoplastics with Tunable Physical Properties Enabled by the Stereoregular Copolymerization of Vinyl Ethers

2019 ◽  
Author(s):  
Aaron Teator ◽  
Travis Varner ◽  
Paige Jacky ◽  
Karolina Sheyko ◽  
Frank Leibfarth
Keyword(s):  
Glass Transition ◽  
Phosphoric Acid ◽  
Vinyl Ether ◽  
Lewis Acid ◽  
Acid Chloride ◽  
Material Properties ◽  
Cationic Polymerization ◽  
Chemical Space ◽  
Vinyl Ethers ◽  
Post Functionalization

A series of isotactic, semicrystalline vinyl ether copolymers (up to 94% <i>meso</i> diads) were synthesized using a chiral BINOL-based phosphoric acid in combination with a titanium Lewis acid. This stereoselective cationic polymerization enabled the systematic tuning of both glass-transition (<i>T</i><sub>g</sub>) and melting temperature (<i>T</i><sub>m</sub>) in copolymers derived from alkyl vinyl ethers (<i>i.e.</i>, ethyl, butyl, isobutyl). Additionally, a vinyl ether comonomer bearing an acyl-protected alcohol was utilized as a platform for post-functionalization. Copolymers containing the masked alcohols were shown to undergo facile deprotection and subsequent coupling with a desired acid chloride. Collectively, these results highlight the diverse material properties and expanded chemical space accessible through stereoselective cationic polymerization mediated by a chiral anion.

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