Butyl Vinyl Ether Research Articles

Radiation-chemical synthesis of thermosensitive copolymers based on the vinylbutyl ether and their complexing and emulgating abilities

Novel water-soluble thermosensitive copolymers of vinyl butyl ether (VBE) with vinyl ether of ethyleneglycol (VEEG) and N-vinylpyrrolidone (NVP) and ternary copolymers based on VBE, 2-hydroxyethylacrylate (HEA) and acrylic acid (AA) were synthesized by γ-induced radiation copolymerization. The composition of copolymers and average molecular weight of copolymers were determined using NMR 13C-spectroscopy and gel-permeation chromatography. It was shown that aqueous solutions of VBE–VEEG, VBE–NVP, VBE–HEA–AA have lower critical solution temperature (LCST) depending on copolymer composition. The complexation of copolymers with polyacrylic acid (PAA) was studied by turbidimetry method. Critical pH value of complexation (pH crit.) was used as the criterion of complexing ability. The effect of composition and concentration of copolymers, as well as pH of medium on the formation of IPC was investigated. The effect of VBE–VEEG copolymers of different compositions on the stability of model hexane–water emulsions was studied. It was determined that the regulation of hydrophilic–hydrophobic balance of macrochains and copolymer concentration allows effectively influence on the stability of hexane–water emulsions.

Synthesis of poly(vinyl ether) plastics for optical use by cationic copolymerization of tricyclodecyl vinyl ether with n‐butyl vinyl ether

Cationic copolymerizations of 8-vinyloxytricyclo[5.2.1.02,6]decane (TCDVE; tricyclodecane unit-containing vinyl ether) with n-butyl vinyl ether (NBVE) as a linear alkyl vinyl ether were undertaken in toluene solvent with living cationic initiators and BF3OEt2 as a non-living initiator. The Tg's of the copolymers of TCDVE and NBVE [poly(TCDVE-ran-NBVE)] was controlled by changing the copolymer composition. The copolymers showed similar transparency to those of polymethyl methacrylate (PMMA) and polycarbonate (PC), which are conventional optical plastics, and even lower specific gravity and water absorption than PMMA and PC. [Color figure can be viewed in the online issue, which is available at www.interscience.wiley.com.]

Novel in situ polymerized coatings for hydrophobic interaction chromatography media

Hydrophobic interaction chromatography (HIC) and other capture media are typically produced by grafting different ligands to base matrices at defined surface densities. This often complicates media production. An alternative approach to media involving in situ radical initiated polymerization was used to graft polymer coatings directly at Sepharose® polymeric base matrices. This method appears suitable for producing many different chromatography media on a variety of base matrices. In the present study, it also favorably increased the solution pressure-flow properties of a Sepharose base matrix used to produce HIC media. A wide range of HIC media could be produced by simply varying the reaction ratio of butyl vinyl ether, and hydroxybutyl vinyl ether. The new HIC media was evaluated using five test proteins (bovine serum albumin, ribonuclease A, α-chymotrypsinogen A, myoglobin and α-lactalbumin). The media exhibited classic HIC behavior, predictably controlled hydrophobicity, plus good protein selectivity, capacity (70 mg protein/ml gel) and often total protein recovery. By modifying the degree of matrix hydrophobicity, we could also reduce effects of protein denaturation often seen with conventional HIC and observed as multiple peaks in the chromatograms. Separation of crude protein extracts from Eschericha coli, expressing a green fluorescent protein (GFPuv) and, a more hydrophobic, recombinantly-modified, tyrosine-tagged green fluorescent protein (YPYPY-GFPuv), was also performed. These proteins were very stable, exhibited significantly different retention times, and could be used to study the ability of the media to work with complex protein mixtures. Such GFP mutants appear ideal for characterizing the performance of chromatographic media.

Thermoresponsive and bioactive poly(vinyl ether)-based hydrogels synthesized by radiation copolymerization and photochemical immobilization

A thermoresponsive hydrogel was synthesized by radiation copolymerization of ethylene glycol vinyl ether (EGVE) and butyl vinyl ether (BVE) in the presence of cross-linking agent diethylene glycol divinyl ether. The gel was modified by a cell adhesion factor RGD by photochemical immobilization technique. While the unmodified hydrogel shows fully hydrated form at low temperatures (+4 °C) and it extensively dehydrates at 37 °C, the biomodified hydrogel still kept its thermoresponsive character after immobilization. The effectiveness of immobilization was checked with FTIR-ATR and XPS. The use of bioactive thermoresponsive hydrogels in cell culture applications was investigated. For this purpose, cell culture experiments were realized by L929 mouse fibroblasts. Cell attachment experiments revealed the effect of immobilized RGD with higher values of cell attachment (∼85%), which were obtained especially in the absence of serum. The thermoresponsive character of the hydrogel was useful for the application of low-temperature treatment in order to recover the attached viable cells from the surface of the hydrogel without using trypsin. When the culture temperature was decreased from 37 to 10 °C for 30 min ∼80% of the cells were detached from the hydrogel surface.

Novel chlorhexidine releasing system developed from thermosensitive vinyl ether‐based hydrogels

The aim of this study is to determine the effective concentrations of chlorhexidine on the release for prolonged periods of time from a novel hydrogel system. A hydrogel that exhibits a volume phase transition in response to temperature was synthesized by radiation copolymerization of ethylene glycol vinyl ether and butyl vinyl ether in the presence of crosslinking agent, diethylene glycol divinyl ether. Hydrogel samples in the disc form (diameter, 10 mm and height, 1.5 mm) were utilized as a matrix for the release of an antimicrobial agent, chlorhexidine diacetate. Chlorhexidine loading into the hydrogel was performed by water sorption at 4 degrees C, which allows high swelling and thus high loading capacity, i.e., approximately 36 mg drug per gram of dry gel. Chlorhexidine release was examined as short-term (24 h) and long-term (27 days) by UV spectrophotometer. Microbial studies were carried out by micro-dilution method in order to determine the effectiveness of the drug release. Minimum inhibitory concentration values for the pathogens of Streptococcus mutans and Lactobacillus casei were determined. The long-term chlorhexidine release is initially very fast. After that, the drug release reaches a slow but a steady rate. Such a release pattern provides an effective drug release. The prolonged release of chlorhexidine is continued up to the 27th day. MIC values for the two pathogens have been shown that the release rate from disc is effective to inhibit the growth of pathogens. These in vitro drug release results suggested that the thermosensitive hydrogel system developed in this study can be evaluated as a delivery system for the release of chlorhexidine.

2‐Iminopyridylpalladium dichloride as highly active catalyst for the Heck reaction

AbstractHeck reactions of bromoarenes with various olefins catalyzed by 2‐iminopyridylpalladium (II) have been investigated. The scope of a coupling reaction has been tested in 1‐methyl‐2‐pyrrolidinone at 140 °C using K2CO3 as base. Using 0.1% molar ratio of palladium catalysts, aryl bromides were converted into 1,2‐substitutedethene products in good to high yields through coupling with both vinylarenes and alkylolefins. With butyl vinyl ether, an electron‐rich olefin, however, the effective coupling reaction produced a mixture of two regio‐isomers, 1,2‐ and 1,1‐substitutedethenes. Copyright © 2007 John Wiley & Sons, Ltd.

Polymerization of vinyl compounds in the presence of perfluoroisopropenyl ester

AbstractTo report a new polymerization reaction phenomenon, this article examines the polymerization of butyl vinyl ether and N‐vinylcarbazole in the presence of 2‐benzoxypentafluoropropene [CF2C(CF3)OCOC6H5 or BPFP]. The homopolymer of butyl vinyl ether was produced in the presence of a catalytic amount of BPFP in high yields. N‐Vinylcarbazole, which is a monomer well‐known for producing its homopolymer under cationic polymerization conditions, also yielded its homopolymer in the presence of BPFP. It was concluded that some cationic species would be yielded by the addition of BPFP. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 908–910, 2007.

Pd—mBDPP‐Catalyzed Regioselective Internal Arylation of Electron‐Rich Olefins by Aryl Halides.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

Derivatization of Tetrafluorobenzo[c]thiophene. Preparation of Tetrafluorothiabenzoporphyrin

The Diels-Alder reactions of tetrafluorobenzo[c]thiophene with electron-deficient olefins such p-benzoquinone and bis(phenylsulfonyl)ethylene gave adducts in moderate yields, while no product was obtained in the reaction with butyl vinyl ether. The Vilsmeier reaction gave tetrafluorobenzo[c]thiophene-1-carbaldehyde in good yield. The aldehyde was converted to tetrafluorothiabenzoporphyrin.

Synthesis of Pyrrolidines via Palladium(II)‐Catalyzed Aerobic Oxidative Carboamination of Butyl Vinyl Ether and Styrenes with Allyl Tosylamides.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

Palladium(II)-Catalyzed Synthesis of 2-Alkoxytetrahydrofurans from Allylic Alcohols and Vinyl Ethers: Stereospecificity and Catalysis

The reaction of (E)- or (Z)-cinnamyl alcohol and ethyl vinyl ether with a catalyst consisting of Pd(OAc) 2 , Cu(OAc) 2 , and catechol (1:1:2) under O 2 gives a good yield of(Z)- or (E)-4-benzylidene-2-ethoxytetrahydrofuran, respectively. Similarly, 2-butoxy-4-exomethylenetetrahydrofuran was obtained from allyl alcohol and butyl vinyl ether. In the case of allyl alcohol, however, the catalysis does not proceed well with forming palladium black, if a relatively large amount of Pd(OAc) 2 , such as 0.25 mmol to 0.05 mmol, is used even in a lower palladium/substrate ratio, e.g. 1 mol% concentration of the catalyst.

Kinetic and Mechanistic Study of the Gas-Phase Reactions of a Series of Vinyl Ethers with the Nitrate Radical

NO(3) oxidation of methyl, ethyl, propyl, and butyl vinyl ethers has been studied under tropospheric conditions (atmospheric pressure and T = 293 +/- 3 K) in the LISA indoor simulation chamber. NO(3) was produced inside the reactor by thermal decomposition of N(2)O(5) previously added to the air-VOC mixture, and concentrations were monitored using FTIR spectrometry. All the kinetic experiments were carried out by relative rate technique using isoprene as reference compound, leading to the rate constants k(1) = (7.2 +/- 1.5) x 10(-13), k(2) = (13.1 +/- 2.7) x 10(-13), k(3) = (13.3 +/- 3.0) x 10(-13), and k(4) = (17.0 +/- 3.7) x 10(-13) cm(3) molecule(-1) s(-1) for methyl, ethyl, propyl, and butyl vinyl ethers, respectively. Main oxidation products have been identified like being formaldehyde and respectively methyl, ethyl, propyl, and butyl formates. Production yields of oxidation products were close to 50%. Oxygenated nitrates and peroxynitrates were also detected.

Pd−mBDPP-Catalyzed Regioselective Internal Arylation of Electron-Rich Olefins by Aryl Halides

meso-2,4-Bis(diphenylphosphino)pentane (mBDPP) has proved to be an effective regiocontrolling ligand for palladium-catalyzed internal arylation by aryl bromides of electron-rich olefins in a common solvent DMSO with no need for any halide scavengers. The arylation of the benchmark electron-rich olefin butyl vinyl ether took place smoothly to afford exclusively alpha-arylated product with high isolated yields. The better performance of mBDPP, compared with that of the commonly used DPPP [1,3-bis(diphenylphosphino)propane], highlights the important but subtle effect of ligand on the regioselectivity of the Heck arylation reactions.

Synthesis of Pyrrolidines via Palladium(II)-Catalyzed Aerobic Oxidative Carboamination of Butyl Vinyl Ether and Styrenes with Allyl Tosylamides

[Structure: see text] Palladium(II) catalyzes the oxidative coupling of allyl tosylamides with butyl vinyl ether and various styrene derivatives to produce 2,4-substituted pyrrolidine products at room temperature. Molecular oxygen together with a copper(II) cocatalyst mediates reoxidation of the palladium catalyst. The reactions with styrene substrates can be performed in an open flask with ambient air as the source of O2. Several nontraditional cocatalysts, including catechol, cyclooctadiene, and methyl acrylate, have a beneficial effect on the reactions.

Kinetic Study of the Gas-Phase Reactions of OH and NO3 Radicals and O3 with Selected Vinyl Ethers

Kinetic studies on the gas-phase reactions of OH and NO3 radicals and ozone with ethyl vinyl ether (EVE), propyl vinyl ether (PVE) and butyl vinyl ether (BVE) have been performed in a 405 L borosilicate glass chamber at 298 +/- 3 K in synthetic air using in situ FTIR spectroscopy to monitor the reactants. Using a relative kinetic method rate coefficients (in units of cm3 molecule(-1) s(-1)) of (7.79 +/- 1.71) x 10(-11), (9.73 +/- 1.94) x 10(-11) and (1.13 +/- 0.31) x 10(-10) have been obtained for the reaction of OH with EVE, PVE and BVE, respectively, (1.40 +/- 0.35) x 10(-12), (1.85 +/- 0.53) x 10(-12) and (2.10 +/- 0.54) x 10(-12) for the reaction of NO3 with EVE, PVE and BVE, respectively, and (2.06 +/- 0.42) x 10(-16), (2.34 +/- 0.48) x 10(-16) and (2.59 +/- 0.52) x 10(-16) for the ozonolysis of EVE, PVE and BVE, respectively. Tropospheric lifetimes of EVE, PVE and BVE with respect to the reactions with reactive tropospheric species (OH, NO3 and O3) have been estimated for typical OH and NO3 radical and ozone concentrations.

A Hetero-Diels−Alder Approach to Complex Pyrones: An Improved Synthesis of the Spongistatin AB Spiroketal

The conversion of a substituted dioxinone to a pyrone was used in an improved synthesis of the AB spiroketal subunit of the spongistatins. This transformation occurred via a hetero-Diels-Alder reaction of an acyl ketene with butyl vinyl ether. A double diastereoselective Mukaiyama aldol reaction is used to provide the hetero-Diels-Alder precursor.

Synthesis of oligocaprolactone vinyl ether macromonomers and their use for indomethacin encapsulation in polymer nanoparticles based on polycaprolactone macromonomer–maleic anhydride–N‐vinyl pyrrolidone terpolymers

AbstractOligocaprolactone macromonomers functionalized with vinyl ether have been synthesized by polymerization of ε‐caprolactone in the presence of hydroxy ethyl or butyl vinyl ether and characterised by NMR and Maldi time‐of‐flight mass spectroscopy. These macromonomers have been copolymerized with maleic anhydride and N‐vinyl pyrrolidone to give terpolymers, which have been used to obtain nanoparticles by the phase‐separation‐dialysis method. Previously dissolving indomethacin in the terpolymer solution allows one to encapsulate the drug inside the nanoparticles. Copyright © 2005 Society of Chemical Industry

Novel temperature‐responsive water‐soluble copolymers based on 2‐hydroxyethylacrylate and vinyl butyl ether and their interactions with poly(carboxylic acids)

AbstractNovel water‐soluble amphiphilic copolymers have been synthesized by free radical copolymerization of 2‐hydroxyethylacrylate with vinyl butyl ether. In water these copolymers exhibit lower critical solution temperature, which depends on the content of hydrophobic vinyl butyl ether units. The interaction between these copolymers and poly(acrylic acid) or poly(methacrylic acid) in aqueous solutions results in formation of interpolymer complexes stabilized by hydrogen bonds and hydrophobic interactions. An increase in hydrophobicity of the copolymers leads to the enhancement of their complex formation ability with respect to poly(acrylic acid) and poly(methacrylic acid). Poly(methacrylic acid) forms stronger complexes with the copolymers when compared with poly(acrylic acid). The complexes exhibit dual sensitivity to pH‐ and temperature and this property may be easily adjusted regulating the strength of interaction. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 195–204, 2006

Release kinetics of bovine serum albumin from pH-sensitive poly(vinyl ether) based hydrogels

pH-Sensitive amphiphilic hydrogels were synthesized by radiation copolymerization of ethylene glycol vinyl ether (EGVE), butyl vinyl ether (BVE) and acrylic acid (AA) in the presence of crosslinking agent, diethylene glycol divinyl ether (DEGDVE). The results of the swelling experiments indicated that the hydrogel which has 60:40:5 comonomer ratio (mol% of EGVE:BVE:AA in monomeric mixture) is pH-sensitive. While the hydrogel is in a fully hydrated form at pH > 6, it extensively dehydrates below pH 6. A two-stage volume phase transition was observed in the range of pH 6.0–7.0 and 7.5–8.0. In addition, the equilibrium water contents of the gels decreased with increasing temperature from 4 to 37 °C by following the non-Fickian diffusion mechanism. The utility of pH-sensitive gels in delivery of protein based drugs was investigated. Bovine serum albumin (BSA) loaded gels were prepared and protein release was examined by fluorescence spectroscopy in the range of pH 2–9. While the protein release was very low at pH 2, readily high amount of BSA were released at pH > 6. It was concluded that the pH-sensitive EGVE–BVE–AA terpolymers may be suitable for the oral administration of protein based drugs as a carrier through gastrointestinal (GI) tract.

Vinyl ether/acrylic acid terpolymer hydrogels synthesized by [formula omitted]-radiation: characterization, thermosensitivity and pH-sensitivity

The radiation copolymerization of hydrophilic ethylene glycol vinyl ether (EGVE), hydrophobic butyl vinyl ether (BVE) and/or acidic comonomer acrylic acid (AA) was realized in the presence of crosslinking agent diethylene glycol divinyl ether (DEGDVE). The swelling studies which were carried out at 4 and 37 °C in phosphate buffer solution (PBS, pH 7.4) showed that equilibrium swelling ratios of the hydrogels (except EGVE homopolymer hydrogel) decreases with increasing temperature and swelling process obeys non-Fickian diffusion mechanism. The pH-dependent swelling behaviour of the hydrogels was examined in buffered solutions at various pHs. The swelling process is reversible and pH-dependent for the AA-containing hydrogel. While this hydrogel shows a fully hydrated form at pH>6; it extensively dehydrates below pH 6. The gels are stable after the repeated swelling experiments. The molecular structure of the hydrogels was studied by Fourier Transform Infrared Spectroscopy and their thermal behaviour was investigated by Differential Scanning Calorimetry and Thermal Gravimetric Analysis. The surface and cross-section structures of the gels were examined by a Scanning Electron Microscope.