Effect of central spacer chain structure on cationic cyclopolymerization tendency of divinyl ethers

Abstract

To clarify the effects of the central spacer chain structure of divinyl ethers on their cationic cyclopolymerization tendencies, 1,4‐bis[(2‐vinyloxy)ethoxy]benzene (1), 1,4‐bis[(2‐vinyloxy)ethoxy]butane (2), 1,6‐bis[(2‐vinyloxy)ethoxy]hexane (3), 1,8‐bis[(2‐vinyloxy)ethoxy]octane (4), and 1,4‐bis[(4‐vinyloxy)butoxy]butane (5) were polymerized with the hydrogen chloride/zinc chloride (HCl/ZnCl2) initiating system in methylene chloride (CH2Cl2) at 0 °C at low initial monomer concentration ([M]0 = 0.15 M). The polymerizations of divinyl ethers 2 and 3 gave soluble polymers quantitatively. In contrast, the polymerizations of divinyl ethers 1, 4, and 5 underwent gel formation at high monomer conversion. The content of the unreacted vinyl groups of the obtained soluble polymers was measured by 1H NMR spectroscopy. Judging from the relatively low vinyl contents of the polymers produced even in the early stage of the polymerization (monomer conversion < ∼20%), the cyclopolymerization occurred to some extent for 2, 3, and 4. On the contrary, the polymers produced from 1 and 5 exhibited the relatively high vinyl content, indicating that the cyclopolymerization tendencies of 1 and 5 were lower than those of 2, 3, and 4. These results are discussed in terms of the structural variety of the spacer chains: (1) the presence of benzene ring (1 vs 2), (2) their length (2 vs 3 and 4), and (3) the position of ether oxygen (4 vs 5). © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 4002–4012, 2002

Living cationic polymerization of vinyl ethers with a tricyclodecane or tricyclodecene unit: Synthesis of new poly(vinyl ether)s with high glass‐transition temperature

“…1 , 2 , and 3 (all are mixtures of the isomers shown in Scheme ) were supplied by Maruzen Petrochemical (Tokyo, Japan), and purified by distillation under reduced pressure before use: 1 , bp 49 °C/0.5 mmHg, density 0.99 g/mL; 2 , bp 45 °C/0.2 mmHg, density 1.01 g/mL; 3 , bp 56 °C/0.5 mmHg, density 1.00 g/mL. Toluene (solvent for polymerization), diethyl ether (solvent for ZnCl 2 ), and tetrahydronaphthalene (internal standard for gas chromatography) were purified as described in the previous reports 14, 16. HCl (4.0 M solution in dioxane) and ZnCl 2 (1.0 M solution in diethyl ether) were commercially supplied by Aldrich (Milwaukee, WI) and used without further purification.…”

“…The polymerization was performed under a dry nitrogen atmosphere in a glass tube equipped with a three‐way stopcock as already reported 14, 16. Conversions of monomers were determined from its residual concentration measured by gas chromatography with tetrahydronaphthalene as an internal standard.…”

“…The molecular weight distributions (MWDs) of the polymers were measured by gel permeation chromatography (GPC) in chloroform (at a 1.0 mL/min flow rate) at 40 °C on a Shimadzu LC‐10AD chromatograph equipped with four polystyrene gel columns (Shodex K‐805L × 1 and K‐804L × 3), a Shimadzu RID‐6A refractive index detector, and a Hitachi L‐7400 ultraviolet detector. The number‐average molecular weight ( M n ) and polydispersity ratio [weight‐average molecular weight/number‐average molecular weight ( M w / M n )] were calculated from chromatograms on the basis of polystyrene calibration 14, 16. To obtain absolute molecular weights of the polymers, GPC coupled with a multiangle laser light scattering (GPC/MALLS) was conducted in tetrahydrofuran (at a 1.0 mL/min flow rate) at room temperature (about 28 °C) on a Shodex HPLC equipped with Wyatt Technology DOWN EOS detector (wavelength, 690 nm), Shodex RI‐101 refractive index detector, and polystyrene gel columns (Shodex KF‐806L × 2).…”

“…To obtain absolute molecular weights of the polymers, GPC coupled with a multiangle laser light scattering (GPC/MALLS) was conducted in tetrahydrofuran (at a 1.0 mL/min flow rate) at room temperature (about 28 °C) on a Shodex HPLC equipped with Wyatt Technology DOWN EOS detector (wavelength, 690 nm), Shodex RI‐101 refractive index detector, and polystyrene gel columns (Shodex KF‐806L × 2). 1 H NMR spectra were obtained in toluene‐ d 8 at room temperature as mentioned elsewhere 14, 16. Differential scanning calorimetry (DSC) was performed with Rigaku Thermo Plus DSC 8230L.…”

Cationic cyclopolymerization of 1,2‐bis(2‐vinyloxyethoxy)benzenes: Introduction of bulky substituents to increase cyclopolymerization tendency

“…Another problem concerns contribution of postreactions of the residual unreacted vinyl groups in the polymers (e.g., crosslinking and branching reactions) especially in the later stage of the polymerization when one measures the degree of cyclization on the basis of the amount of the residual unreacted vinyl groups in the polymers. Indeed, even in the cases of the degree of cyclization well below 100%, completely soluble poly(divinyl ether)s with no residual unreacted vinyl groups can be formed in the final stage of the polymerization, if intramolecular crosslinking reactions and/or branching reactions frequently occur 20, 24–27…”