Polymerization Of Isobutyl Vinyl Ether Research Articles

Study on the cationic polymerization of isobutyl vinyl ether initiated by dual active species based on [Ph3C][B(C6F5)4] and its mechanism

AbstractThe cationic polymerization of isobutene vinyl ether(IBVE) contains waters system was achieved by using triphenylmethylium tetrakis‐(pentafluorophenyl)borate [Ph3C][B(C6F5)4], which overcame the harsh experimental requirements of traditional cationic polymerization. The influences of water content, solvent polarity, and reaction temperature on polymerization were studied. The end structure of the polymer was analyzed by 1H‐NMR. Combined with the effect of the proton trapping agent and triethylamine salt which can trap [H+], it was found that there was a reversible equilibrium between [Ph3C+] and [H+] active species during the polymerization process. The cationic polymerizations of isobutyl vinyl ether were initiated by these two active species simultaneously. The controllable cationic polymerization of isobutyl vinyl ether was achieved by the addition of ethyl methyl carbonate and ethyl benzoate. Gaussian 09 W simulation confirms the polymerization mechanism.

Visible light‐catalyzed living cationic homopolymerization and copolymerization of isobutyl vinyl ether: Characteristics and mechanism

AbstractOn the basis of synthesizing a highly efficient chain‐transfer agent ethyl (1‐isobutoxyethyl) carbonotrithioate(CTA), living cationic polymerization of isobutyl vinyl ether (IBVE) was successfully initiated by visible light catalysis. The random copolymerization of isobutyl vinyl ether and propyl vinyl ether (PVE), cyclohexyl vinyl ether (CyVE), and 2‐chloroethyl vinyl ether (CEVE) was achieved on the basis of investigating the reactivity ratios of vinyl ether monomers. The influence of photocatalyst (PC) concentration and wavelength on the copolymerizations was investigated. It was found that high PC concentration results in a fast polymerization rate. The wavelength of the blue LED was most suitable for this reaction system. This photocatalytic reaction provides a new way for molecular design of cationic polymerization.

Application of Thiourea/Halogen Bond Donor Cocatalysis in Metal-Free Cationic Polymerization of Isobutyl Vinyl Ether and Styrene Derivatives

Application of Thiourea/Halogen Bond Donor Cocatalysis in Metal-Free Cationic Polymerization of Isobutyl Vinyl Ether and Styrene Derivatives

Synthesis of Block Copolymers by Mechanistic Transformation from Reversible Complexation Mediated Living Radical Polymerization to the Photoinduced Radical Oxidation/Addition/Deactivation Process.

A versatile strategy for the fabrication of block copolymers by the combination of two discrete living polymerization techniques—reversible complexation mediated living radical polymerization (RCMP) and photoinduced radical oxidation addition deactivation (PROAD) processes—is reported. First, RCMP is conducted to yield poly(methyl methacrylate) with iodide end groups (PMMA-I). In the following step, PMMA-I is used as macroinitiator for living PROAD cationic polymerization of isobutyl vinyl ether. Successful formation of the block copolymers is confirmed by 1H NMR, FT-IR, GPC, and DSC investigations.

A continuous flow-through strategy to produce highly isotactic poly(isobutyl vinyl ether)viacationic polymerization

Tubular reactor strategy is designed for the continuous flow cationic polymerization of isobutyl vinyl ether, which gives higher isotacticity than conventional batch process and demonstrates technical advantages for potential industrial applications.

Magnesium bromide (MgBr2) as a catalyst for living cationic polymerization and ring-expansion cationic polymerization

Magnesium bromide (MgBr2) was found to be an effective catalyst for the ring-expansion cationic polymerizations of isobutyl vinyl ether (IBVE) initiated by a “cyclic” hemiacetal ester (HAE) bond-based initiator leading to the syntheses of cyclic poly(IBVE)s.

Controlled Synthesis of Poly(vinyl ether)-Grafted Poly(phenylacetylene)s by a Combination of Living Coordination Polymerization and Living Cationic Polymerization.

We newly designed a functionalized monomer (PhAVE-AcOH) containing a phenylacetylene (PhA) group and a 1-(acetoxy)ethoxy group, the latter of which is expected to act as an initiator moiety in combination with Lewis acid-based activators under living cationic polymerization conditions. A polyPhA-based multifunctional initiator poly(PhAVE-AcOH) with a narrow molecular weight distribution (Mw/Mn = 1.02) was synthesized by Rh complex-mediated living coordination polymerization of PhAVE-AcOH. Then, living cationic graft polymerization of isobutyl vinyl ether (IBVE) was performed employing the pendant 1-(acetoxy) ethoxy initiating moiety of poly(PhAVE-AcOH) to form polyIBVE-grafted polyPhA(polyPhA-g-polyIBVE), where both the main chain and side chains possessed well-controlled structures (Mw/Mn = 1.05–1.10). We found that UV–vis absorption spectra of polyPhA-g-polyIBVE were progressively redshifted with increasing molecular weights of the graft chain.

Tetradentate schiff base ligand/MCln initiating systems for the controlled cationic polymerization of isobutyl vinyl ether: Effects of the ligand framework

ABSTRACTWe investigated the cationic polymerization of vinyl ethers using metal complex catalysts with salen and salphen ligands. Metal complexes were generated in situ from the reaction of a ligand and a metal chloride. The choice of a ligand and a central metal was crucial for tuning the catalyst function such as catalytic activity and controllability of the polymerization. Among metal chlorides employed, ZrCl4 was the most efficient for controlled polymerization. Cationic polymerization of isobutyl vinyl ether (IBVE) proceeded using the salen and salphen‐type ligand/ZrCl4 initiating systems, yielding polymers with predetermined molecular weights and narrow molecular weight distributions. Importantly, the structural effects of the complex catalysts were responsible for the polymerization behavior. For example, the polymerization using the salen‐type ligand/ZrCl4 system was much slower than that using the salphen‐type ligand/ZrCl4 system. In addition, the polymerization of IBVE using the salen‐type ligand/FeCl3 system proceeded in a controlled manner, which was in contrast to uncontrolled polymerization using the salphen‐type ligand/FeCl3 system. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 989–996

Fast living cationic polymerization of isobutyl vinyl ether tailored by single nucleophile in microflow system

The application of living cationic polymerization suffers from complex and costly additives as well as low productivity. In this work, we attempted to develop fast living cationic polymerization of isobutyl vinyl ether (IBVE) tailored by reduced single nucleophile in microflow system. Living polymers were successful obtained for the systems of IBVE-HCl/FeCl3·DO/DO and IBVE-HCl/FeCl3·DOL/DOL. The kinetic behavior of IBVE polymerizations at various concentration of nucleophiles revealed that a microflow system could afford living characteristics as the time to reach 50% conversion (t1/2) is as short as 0.22 s. Using single nucleophile can avoid the negative cooperativity of multi-nucleophiles in stabilizing carbocations, allow the decrement of nucleophile, and enhance the controllability of polymerization process. DFT simulations indicate that only the nucleophile with relatively higher binding energy could endow the system with living characteristic. From this point of view, the addition of other nucleophile with relatively lower binding energy may have no positive effect. These recognitions are meaningful for the development of living cationic polymerization towards commercial application.

Block Copolymers by Mechanistic Transformation from PROAD to Iniferter Process.

A facile strategy for synthesizing block copolymers by the combination of two different living polymerization techniques, namely, photoinduced radical oxidation/addition/deactivation (PROAD) and iniferter processes is described. In the first step, PROAD polymerization of isobutyl vinyl ether using bromotriphenylmethane, dimanganese decacarbonyl (Mn2 (CO)10 ), and diphenyliodonium bromide (Ph2 I+ Br- ) is carried out to yield polymers with triphenylmethyl (trityl) end groups. These prepolymers are used as macroiniferters in thermally induced free radical polymerization of vinyl monomers such as methyl methacrylate, tert-butyl acrylate, and styrene, resulting in the formation of corresponding block copolymers free from homopolymers. The precursor polymer and final block copolymers are characterized by 1 H NMR, FT-IR, GPC, and DSC analyses.

Achieving Low-Cost and Accelerated Living Cationic Polymerization of Isobutyl Vinyl Ether in Microflow System

In this work, we proposed and realized a strategy for fast and low-cost living cationic polymerization of isobutyl vinyl ether (IBVE) based on temporary stability of propagating chain. It combines the decrease of added-base addition to increase the polymerization rate and the use of microflow system to enhance process regulation. To ensure the living characteristic, the concentration of added-base DO was allowed to be as low as 0.1 M for IBVE–HCl/SnCl4/DO initiation system and 0.5 M for IBVE–HCl/FeCl3/DO initiation system, respectively; the time to achieve 80% conversion could decrease to around 5 s. We also discussed the effect of reaction mode on the polymerization performances and recognized the mechanism and requirement to achieve living cationic polymerization at decreased added-base addition. These recognitions may broaden the horizon of living cationic polymerization and improve its commercial value with respect to productivity and cost.

Thermally induced cationic polymerization of isobutyl vinyl ether in toluene in the presence of solvate ionic liquid

Cationic polymerization of isobutyl vinyl ether at elevated temperatures of 60–100 °C, in which the propagating cations are stabilized with a solvate ionic liquid, is described.

Halogen-Bonding-Mediated and Controlled Cationic Polymerization of Isobutyl Vinyl Ether: Expanding the Catalytic Scope of 2-Iodoimidazolium Salts.

Metal-free initiating systems for living cationic polymerizations are desirable from the viewpoint of environmentally benign polymer synthesis. We describe here the development of a halogen-bonding-mediated and controlled cationic polymerization of isobutyl vinyl ether (IBVE) using 2-iodoimidazolium salts as an organocatalyst. Due to the ionic nature of the catalysts, the polymerization should be performed in CH2 Cl2 . The HCl-adduct of IBVE was the most suitable initiator, and the polymerization was carried out at -10 °C under the catalyst concentration of 10 mm to suppress alcohol elimination from the polymer chain. The addition of a small amount of nBu4 NCl (0.02 equivalent) was effective to accomplish the controlled cationic polymerization and obtain polyIBVE, having the molecular weight distribution below 1.3.

Triflate esters as in-situ generated initiating system for carbocationic polymerization of vinyl ethers, isoprene, myrcene and ocimene

Thermo-induced carbocationic polymerization of isobutyl vinyl ether (IBVE), isoprene, myrcene and ocimene is reported using triflate esters as in-situ generated single-molecule initiating system. 3-Methyl-2-butenyl triflate is used for IBVE polymerization at room temperature resulting in polymers with Mn∼9500gmol−1 and Mw/Mn∼2. Triflate-ester initiated polymerization of isoprene leads to oligomers with branched and ultimately cross-linked structures. Myrcene cationic polymerization, in CH2Cl2 or cyclohexane, using 2-propenyl triflate and 1-(4-metoxyphenyl)ethyl triflate as initiators yields low molar mass oligomyrcenes with loss of olefinic protons. Ocimene cationic polymerization is reported for the first time.

Cationic polymerization of vinyl ethers with alkyl or ionic side groups in ionic liquids

ABSTRACTControlled cationic polymerization of isobutyl vinyl ether was demonstrated to proceed in an ionic liquid (IL), 1‐butyl‐3‐octylimidazolium bis(trifluoromethanesulfonyl)imide, using a 1‐(isobutoxy)ethyl acetate/TiCl4 initiating system, ethyl acetate as an added base, and 2,6‐di‐tert‐butylpyridine as a proton trap reagent. Judicious choices of metal halide catalysts, counteranions of ILs, and additives were essential for controlling the polymerization. The polymerization proceeded much faster in the IL than in CH2Cl2, indicating an increased population of ionic active species in the IL due to the high polarity. Polymers with a relatively narrow molecular weight distribution were obtained in the IL with a bis(trifluoromethanesulfonyl)imide ( ) anion even in the absence of an added base, which suggested possible interactions of the counteranion of the IL with the growing carbocations. Moreover, the direct cationic polymerization of a vinyl ether with pendant imidazolium salts, 1‐(2‐vinyloxyethyl)‐3‐methylimidazolium bis(trifluoromethanesulfonyl)imide, proceeded in a homogeneous state in 1‐methyl‐3‐octylimidazolium bis(trifluoromethanesulfonyl)imide. The solubilities of the obtained polymers were readily tuned by counteranion exchange. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 1774–1784

Rapid living cationic polymerization of vinyl ethers by a single-molecular initiating system

Initiated by an organic molecule trifluoromethanesulfonimide (HNTf2) without any Lewis acid or Lewis base stabilizer, cationic polymerization of isobutyl vinyl ether (IBVE) takes place rapidly and the polymerization is proved to be in a controlled/living manner. The conversion of IBVE could easily achieve 99% in seconds. The product poly(isobutyl vinyl ether) is narrowly distributed and its molecular weight increases linearly with time and fits well with the corresponding theoretical value. This single-molecular initiating system also works well in the living cationic polymerization of ethyl vinyl ether. HNTf2 is considered playing multiple roles which include initiator, activator, and stabilizer in the polymerization. It is quite different from the hydrogen halide-catalyzed polymerizations of vinyl ethers. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 1373-1377

Polymerization of vinyl ethers initiated by dendritic cations using flow microreactors

Cationic polymerization of vinyl ethers initiated by an electrogenerated dendritic diarylcarbenium ion in the presence of 2,6-di-tert-butylpyridine was developed using a flow microreactor. The carbocationic polymer end generated by polymerization of isobutyl vinyl ether was effectively trapped by various nucleophiles such as trimethyl(1-phenylvinyloxy)silane and allyltrimethylsilane to give polymers with very narrow molecular weight distribution. The block copolymerization of two vinyl ethers followed by trapping with nucleophiles was successfully accomplished to give structurally well-defined macromolecules.

A benign initiating system for cationic polymerization of isobutyl vinyl ether: Silver salt/aryl(alkyl) halide/lewis base

ABSTRACTAryl(alkyl) halides and silver salts were studied as environmentally benign initiating systems for cationic polymerization of isobutyl vinyl ether (IBVE). The reactivity of the benzyl cations could be effectively controlled by using dimethyl sulfide (Me2S) as an additive, which was shown to be an effective Lewis base (LB), and diethyl ether as a reaction solvent. Detailed study of various benzyl cations and the order of addition of the reagents revealed that the reaction was controlled by the electronic and steric features of aryl(alkyl) halides, LBs, and IBVE, and a plausible reaction mechanism was presented. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015, 53, 2050–2058

In situ and readily prepared metal catalysts and initiators for living cationic polymerization of isobutyl vinyl ether: dual-purpose salphen as a ligand framework for ZrCl4and an initiating proton source

A well-defined catalyst, generated quantitativelyin situsimply by mixing ZrCl4and a salphen ligand was shown to induce the living cationic polymerization of isobutyl vinyl ether.

Cationic polymerization of isobutyl vinyl ether in an imidazole-based ionic liquid: characteristics and mechanism

Controlled cationic polymerization of IBVE was successfully achieved in an ionic liquid, and corresponding elementary reactions and a mechanism were proposed.