Kinetics of the Copolymerization of Methyl Vinyl Ketone and Acrylamide Initiated by the Adduct of Methyl Vinyl Ketone and Imidazole

N-(Butyl-3-one)imidazole acts as an initiating adduct which is formed in the anionic polymerization of methyl vinyl ketone (MVK) induced by imidazole (Im) and is directly formed from Im and the MVK monomer. The kinetics of the anionic homopolymerization of MVK and acrylamide (AAm) under argon in the presence of the adduct were investigated in tetrahydrofuran (THF). The rate of polymerization for the MVK system is expressed as R_p = k[Adduct] [MVK], where k = 3.1 × 10^?6 L/(mol·s)in THF at 30°C. The overall activation energy, E_a , was found to be 5.34 kcal/mol. The R_p for the AAm system is expressed as R_p = k[Adduct] [AAm], where k = 6.8 × 10^?6 L/(mol·s) in THF at 30°C, with E_a 7.78 kcal/mol. The mechanism of the polymerization induced by the initiator adduct is discussed on the basis of these results.     

Radical Copolymerizability of Acrylamide Derivatives with Methyl Vinyl Ketone

Radical copolymerization of methyl vinyl ketone (MVK, M₁) with acrylamide (AAm) and its derivatives, such as methacrylamide (MAAm) and N,N′ -dimethylacrylamide (DMAAm), was carried out in dioxane or ethanol using α,α - azobisisobutylonitrile as the initiator at 60°C under vacuum. The monomer reactivity ratios found in dioxane were as follows: ri = 1.06, r₂ = 6.41 for the MVK-AAm system; r₁ = 0.29, r₂ = 3.05 for the MVK-MAAm system; and r₁ = 0.95, r₂ = 0.26 for the MVK-DMAAm system. The n and r₂ values obtained in ethanol were as follows: r₁ = 0.88, r₂ = 1.18 for the MVK-AAm system; and r₁ = 0.37, r₂ = 2.04 for the MVK-MAAm system. Q₂ and e₂ values of AAm derivatives in dioxane were estimated to be 3.03 and 1.04 for MAAm and 2.15 and 1.11 for DMAAm, respectively. The Q₂ and e₂ values of MAAm in ethanol were estimated to be 2.67 and 1.21, respectively. Based on these results, the alternating copolymerizability depends on the interaction of monomer-monomer, and the strong solvent effect depends on the radical copolymerization of the AAm derivatives.     

Polymerization of Acrolein by Imidazole

Polymerization of acrolein(AL) in the presence of imidazole(Im) has been investigated in tetrahydrofuran or methanol below room temperature. The polymers obtained, white or pale yellow powders, were found to be composed of vinyl polymer with one Im group attached and having an aldehyde side chain, of which 70–80 mole % of the aldehyde revealed bridge structure. The number-average molecular weight (M _n) of these polymers was determined to be in the range of 317 to 691. The rate of polmerization R_p was expressed by the equation, R + k[Im] [AL]².

The addition of water or dimethyl sulfoxide accelerated the polymerization reaction, while the presence of benzaldehyde or N,N'-dimethylformamide decreased R_p. The structure of addition products in the initial polymerization step was confirmed by IR and NMR spectra, and the observations of polymerization system was carried out by UV and NMR spectra. The polymerization mechanisms were discussed on the basis of these results.     

Additive Effect of p-Substituted Phenols on the Anionic Polymerization of Acrolein Induced by Imidazole

Anionic polymerization of acrolein (AL) by imidazole in the presence of several p-substituted phenols such as phenol, p-methyl-phenol, and p-nitrophenol were kinetically carried out in tetra-hydrofuran at 0°C. The initial polymerization rate R_p was estimated from the rate of monomer consumption by means of gas chromatography. A linear correlation was obtained from Hammett's equation, log R_pX/R_p H = 0.22. Meanwhile, the polymerizabilities were found to be in the following order: p-methylphenol > phenol > p-nitrophenol. The additive effect of phenols was kinetically discussed on the basis of these results.     

Cyclodimerizations and Copolymerizations of Vinyl Ketones with Vinyl Monomers

Stable high-molecular-weight polyacetals can be prepared from formaldehyde or from its trimer trioxane.     

Kinetics and Mechanism of the Reaction of Triphenylphosphine with Methyl Vinyl Ketone

Russian Journal of General Chemistry - Kinetics of the reaction of triphenylphosphine with methyl vinyl ketone has been studied using the stopped flow technique. The experimental data have...     

Aerobic Oxidation of Methyl Vinyl Ketone in Supercritical Carbon Dioxide

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Characterizations and Electric Conductivities of Phosphorous Oxychloride-Treated Polymers Containing Methyl Vinyl Ketone

Abstract

Studies have been made on the characterizations and conductivities of poly(methyl vinyl ketone) (PMVK) and its copolymer with methyl methacrylate (poly(MVK-co-MMA)) after being reacted with phosphorus oxychloride (POCl₃). The POCl₃?treated polymers containing methyl vinyl ketone (MVK) were characterized by IR and UV spectroscopies to prove the structure of conjugated double bonds. The conductivities of all the MVK-containing polymers treated with POCl₃ were very low, ca. 10^?17 S/cm, in a vacuum regardless of the treatment time. The conductivities of the polymers when doped with iodine are in the range of the order of 10^?4 to 10^?6 S/cm. It was found that the conductivity of the POCl₃?treated copolymer is slightly lower than that of PMVK.     

Generation of Methyl Vinyl Ketone from Oxidation of Levulinic Acid Oxidized by Cupric Oxide Complex

Methyl vinyl ketone (MVK) is a kind of high‐value chemical which has been widely used in many fields. In this paper, it is formed from oxidation of levulinic acid–a hydrolysis product of biomass. Copper oxide supported on cerium dioxide (CuO/CeO₂) and alumina (CuO/Al₂O₃) were prepared and used for the oxidation of levulinic acid (LA). The oxidants were characterized by means of X‐ray diffraction (XRD), H₂‐temperature programmed reduction (H₂‐TPR) and atomic force microscope (AFM) techniques. CuO/CeO₂ and CuO/Al₂O₃ show a different behavior with respect to pure CuO. The experiments revealed that CuO/CeO₂ and CuO/Al₂O₃ can oxidize LA and get methyl vinyl ketone [yield of 15.5% detected by head space‐gas chromatograph‐mass spectrometer (HS‐GC‐MS)] under mild reactive conditions, while pure CuO oxidizes LA to produce butanone (MEK).     

Modification of Vinylformamide by Michael Addition to Methyl Acrylate and Methyl Vinyl Ketone,and Copolymers Derived from the Resulting Products

Vinylformamide reacts with methyl acrylate and methyl vinyl ketone under conditions of base catalysis, following the Michael addition pattern, to give methyl 3-(vinylformylamino)propionate and previously unknown 4-(vinylformylamino)-2-butanone. Radical copolymerization of these compounds with vinylformamide and N-vinylpyrrolidone was studied.     

Stereoselective Titanium Mediated Trimerisation of Methyl Vinyl Ketone: A Novel Carbocyclisation Reaction

A new “one pot” stereoselective carbocyclisation reaction involving the trimerisation of methyl vinyl ketone (MVK) in the presence of TiCl₄ is reported.     

Polymerizabilities of Several Polar Vinyl Monomers by Imidazole

Polymerizabilities of several polar vinyl monomers in the presence of imidazole (Im) have been studied in CDC1₃ and CD₃OD by NMR spectra. Acrylic acid formed a bimolecular adduct with Im as the initial adduct, while methacrylic acid was not obtained, On the other hand, methyl acrylate, methyl methacrylate (MMA), acrylamide (AAm), and acrylonitrile formed the initial adduct between Im and monomer, respectively. In these monomers, AAm and MMA gave each polymer in tetrahydrofuranat room temperature. The number-average molecular weight ([Mbar]_n) of AAm polymers was determined to be in the range of 1000 to 1500, and the [Mbar]_n of MMA polymers was found to be in the range of 2500 to 4500, The rate of polymerization R_p was expressed by the equations R_p = k[Im][AAm] and R_p = k[Im] [MMA]², respectively. The activation energy E_R was obtained by Arrheniuss's plots as E_R(AAm) = 9.6 kcal/mol and E_R(MMA) = 3.8 kcal/mol. These polymerization mechanisms are discussed on the basis of these results.     

Sulfur-Containing Vinyl Monomers. XIV. Radical Polymerizations and Copolymerizations of Vinyl Mercaptobenzazoles

Vinyl mercaptobenzazoles [thiazole (VMBT), oxazole (VMBO), and imidazole (VMBI)] were prepared through dehydrochlorination of the respective β-chloroethyl mercaptobenzazoles. These monomers were found to undergo vinyl polymerization in the presence of light or radical initiator, α,α'-azobisisobutyonitrile, to give relatively high molecular weight homopolymers. From the results of radical copolymerizations of these monomers with various monomers, the copolymerization parameters were determined as follows: VMBT(M₂): r₁ styrene(M₁): r₁ = 2.12 ± 0.09, r₂ = 0.336 ± 0.028, Q₂ = 0.75, e_z = ?1.38; VMBO(M₂)-styrene(M₁): r₁ = 2.61 ± 0.13, r₂ = 0.274 ± 0.03, Q₂ = 0.61, e₂ = ?1.38; VBMI(M₂)-styrene(M₁) r₁ =4.0, r₂ = 0.2, Q₂ = 0.37, e₂ = ?1.17. The polymerization reactivities of these monomers obtained from these parameters were compared with those of other vinyl sulfide monomers and discussed.     

Polymerization of Methyl Methacrylate in the Presence of Imidazole Derivatives. Additive Effect of the Initiator Adduct and Copolymerization with Acrylamide

In the anionic polymerization of methyl methacrylate (MMA) induced by imidazole (Im), an Im‐MMA adduct forms as an initiator adduct in methanol at 30°C in an argon atmosphere by the equimolar reaction of Im with the MMA monomer. The additive effect of the adduct on the homopolymerization of MMA in tetrahydrofuran at 30°C was investigated by dilatometry. The existence of the adduct increased the duration of the propagation step without shortening the formation step of the initiator adduct. The H‐D exchange reaction of the adduct was observed in D₂O by ¹H NMR. Proton transfer of the MMA unit in the adduct was not observable until 45 h after initiation. The copolymerizability of MMA with acrylamide (AAm) induced by the Im catalyst in THF at 30°C was also investigated. It was found that the homo‐and copolymerizations proceeded at the same time. On the other hand, in the MMA homopolymerization system, the addition of AAm monomer during the initial propagation step yielded copolymer of MMA and AAm for near equimolar concentration of the charged monomers.     

手性磷酸催化的C（3）-取代吲哚和甲基乙烯基酮不对称串联反应

3位含有季碳手性中心的吲哚啉并环化合物是一类非常重要的化合物, 广泛存在于各种天然产物和具有生物活性的分子中. 化学家们发展了多种有效的途径来合成这类化合物. 其中以方便易得的吲哚衍生物为起始原料, 利用不对称去芳构化\环化串联的方法最为简单高效, 但多数工作都是从色胺或色醇衍生物出发, 合成二氢吡咯并吲哚啉或二氢呋喃并吲哚啉化合物. 因此, 发展其他类型的吲哚衍生物的不对称去芳构化\环化反应显得非常有必要. 作者课题组发展了手性磷酸催化的吲哚衍生物与甲基乙烯基酮的不对称Michael加成\环化串联反应. 以5 mol% (R)-SPINOL为骨架的手性磷酸(R)-4c为催化剂, 以中等到良好的收率和优秀的对映选择性构建了一系列手性吲哚[2,3-b]并氢化喹啉化合物, 而且该催化体系对于克级规模反应同样能够获得很好的结果.     

Vibrational Structure of a High-Resolution UV Absorption Spectrum of Methyl Vinyl Ketone in the Gas Phase

Moscow University Chemistry Bulletin - The resolved vibrational structure of a UV absorption spectrum of the molecule in the gas phase is obtained. The (0–0) bands of the isomers are found....     

Determination of Acrylamide and Acrolein in Smoke from Tobacco and E-Cigarettes

Acrylamide and acrolein are two short-chained hazardous compounds with neurotoxic, carcinogenic, and mutagenic effects. The aim of this paper is to describe a fast and simple procedure for simultaneous determination of both acrylamide and acrolein under standard conditions, suggest a suitable calibration protocol for custom analysis, and demonstrate its applicability to the analysis of gaseous products from, e.g., cigarettes, cigars, or electronic cigarettes. A gas chromatography–mass spectrometry (GC–MS) method was developed to quantify acrylamide and acrolein in smoke vapor from electronic cigarettes, tobacco cigarettes, and cigars. Nonionic and highly polar molecules with a low boiling point and molecular mass need a suitable derivatization method to achieve appropriate retention and selectivity on commonly used relatively nonpolar stationary phases and to enhance the molecular mass for easy MS detection. The derivatization of acrylamide and acrolein was carried out by a bromination method with elemental bromine. The dibromo derivatives were extracted into an organic solvent and following a dehydrobromination procedure the samples were injected into the GC–MS system. Important experimental parameters were varied, after which the bromination time was defined as 30 min, and the injector temperature and the starting temperature of gradient were set at 280 and 50 °C respectively. Acrolein was found in all tested samples, while acrylamide was detected only in smoke from normal tobacco. Possible mechanisms for the formation of these unsaturated compounds in the samples are discussed. After its validation the newly developed method was successfully and reliably applied to the analysis of both compounds. This short method provides an easy way to determine acrylamide and acrolein in gaseous samples.

     

Anionic Polymerizations and Copolymerizations of Methacrylates-Reactivity of Monomer and Tacticity of Polymer

The anionic polymerizations and copolymerizations of methacrylates were investigated. The studies were focused on the stereoregularity of the polymers and the relative reactivity of the monomers in relation to the stereospecificity of polymerization.