共查询到20条相似文献,搜索用时 15 毫秒
1.
Eiichi Ozu Natsuki Yamashita Toshihisa Maeshima Ion C. Baianu Lun-Shin Wei 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(12):1637-1653
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 Rp = k[Adduct] [MVK], where k = 3.1 × 10?6 L/(mol·s)in THF at 30°C. The overall activation energy, Ea , was found to be 5.34 kcal/mol. The Rp for the AAm system is expressed as Rp = k[Adduct] [AAm], where k = 6.8 × 10?6 L/(mol·s) in THF at 30°C, with Ea 7.78 kcal/mol. The mechanism of the polymerization induced by the initiator adduct is discussed on the basis of these results. 相似文献
2.
Natsuki Yamashita Kazuyukiikezawa Shin-Ichirou Ayukawa Toshihisa Maeshima 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(5):615-629
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. 相似文献
3.
Thermal degradation behavior of six alkyl vinyl ketone (RVK) polymers and copolymers with styrene was investigated by means of infrared spectrometry (IR), thermogravimetry (TG), derivative TG (DTG), and differential scanning calorimetry (DSC). The observed TG curves of the RVK polymers changed with both structure of their substituents and initiators used, and the temperature of the beginning of weight loss for the radical polymers increased in the order: poly(methyl isopro-penyl ketone) < poly(methyl vinyl ketone) < poly(ethyl vinyl ketone) < poly(isopropyl vinyl ketone) < poly(tert-butyl vinyl ketone). From the infrared spectral determination of thermally degraded polymers, the formation of a cyclized structure was observed. It was also found from the results of thermal degradation of the RVK copolymers with styrene at 210° C that the formation of such a cyclized unit tended to increase in the order: tert-butyl vinyl ketone < isopropyl vinyl ketone < ethyl vinyl ketone < methyl vinyl ketone. 相似文献
4.
Theaerobicoxidationofethylenetoacetaldehydeandterminalolefinstocorrespondingalkan 2 onescat alyzedbypalladium(II)andcopper(IIorI)saltsarecol lectivelyknownasWackeroxidations (Scheme 1) .1Theyareveryimportantinbothsyntheticandindustrialchem istry .Treatmentoft… 相似文献
5.
6.
Satoshi Morita Kazuyuki Ikezawa Hiroshi Inoue Natsuki Yamashita Toshihisa Maeshima 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(9):1495-1505
The anionic copolymerizations of acrolein (AL) with methyl vinyl ketone (MVK) and acrylamide (AAm) in the presence of imidazole (Im) as an initiator have been studied in tetrahydrofuran at 0°C. The AL-MVK copolymers were found to be composed of vinyl polymer with one Im group attached and having an aldehyde and a carbonyl side chain. The monomer reactivity ratio was determined from a Fineman-Ross plot as r1 = 2.02 and r2 = 0.06. On the other hand, the AL-AAm copolymer were found to be composed of polymer units of 1,2 and 1,4 addition polymerization of AAm. These observations might be explained by the intermolecular hydrogen transfer mechanism of AAm. The polymerization mechanisms were discussed on the basis of these copolymerization results. 相似文献
7.
8.
A new “one pot” stereoselective carbocyclisation reaction involving the trimerisation of methyl vinyl ketone (MVK) in the presence of TiCl4 is reported. 相似文献
9.
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). 相似文献
10.
Ershov A. Yu. Gavrilova I. I. Panarin E. F. 《Russian Journal of Applied Chemistry》2002,75(9):1458-1461
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. 相似文献
11.
12.
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. 相似文献
13.
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.... 相似文献
14.
含亚砜基功能高分子可用作高分子药物载体,高分子螯合剂,高分子催化剂及气体分离膜材料等,近年来已引起各国学者的兴 相似文献
15.
采用密度泛函B3P86方法在6-311++G(d, p)基组水平上优化得到了沿分子轴方向不同外电场(0-0.04 a.u.)作用下, 甲基乙烯基硅酮分子的基态电子状态、几何结构、电偶极矩和分子总能量. 在优化构型下利用杂化CIS-DFT方法(CIS-B3P86)研究了同样外电场条件下对甲基乙烯基硅酮的激发能和振子强度的影响. 计算结果表明, 分子几何构型与电场大小呈现强烈的依赖关系, 分子偶极矩μ随电场的增加先减小后急剧增大. 电场为零时, 分子总能量为-483.5532137 a.u., 随着电场增加, 能量升高, 在F=0.02 a.u.时达到最大值-483.5393952 a.u., 此后, 继续增大电场系统总能量则开始降低. 激发能随电场增加急剧减小, 表明在电场作用下, 分子易于激发和离解. 相似文献
16.
In 1926 Semon tried to dehydrohalogenate high molecular weight poly(vinyl chloride) (PVC) in a high boiling solvent to get an unsaturated polymer which might bond rubber to metal. Unexpectedly, he obtained plasticized PVC, a flexible product inert both electrically and chemically. This discovery opened the door to the commercialization of PVC, a plastic with an annual United States production now exceeding 6 billion pounds. Special PVC's and PVC products have been developed taking advantage of the many favorable properties. Rigid structural products from house siding to pipes are becoming of increasing importance. Two main types of polymers have been utilized: 1) one prepared by suspension polymerization, and 2) a special variety prepared by colloidal polymerization and spray drying. This latter material has been especially useful for making plastisols. Plasticizers and stabilizers were developed to maximize useful and nontoxic properties. Vinyl chloride monomer (VCM) production and co-polymerization evolved as lower cost processes, higher quality products, and greater manufacturing safety were introduced. Recent challenges for the industry have included pollution and carcinogenic hazards which have been overcome by imaginative new technologies. The rate of growth of the industry is shown graphically. 相似文献
17.
Charles E. Carraher JR. 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(8):1293-1356
This review emphasizes the breadth of metallic and metallic-like polymers evaluated as to thermal properties. Techniques usefully applied to particular systems are noted with the aim of suggesting their application to other systems. 相似文献
18.
Cationic polymerizations of 2,3-dihydropyran derivatives, methyl isopropenyl ketone cyclodimer (MIPKD), chloromethyl vinyl ketone cyclodimer (CMVKD), and methyl isopropenyl ketone-chloromethyl vinyl ketone cyclocodimer, D(MIPK-CMVK), were investigated in the presence of various Lewis acids at 0°C. These monomers were found to undergo cationic polymerization to give low molecular weight polymer which consisted mainly of a vinylene structure. However, the ring-opening polymerization was found to occur to a minor extent in cationic polymerizations of MIPKD and D(MIPK-CMVK) cyclodimer. 相似文献
19.
Shou‐Ri Sheng Xiao‐Ling Liu Yong‐Fen Tong Lie Chen Hong‐Li Wen Cai‐Sheng Song 《中国化学会会志》2005,52(5):943-946
Several new methyl substituted poly(aryl ether ketone)s containing sulfone linkage with inherent viscosities of 0.62–0.84 dL/g have been prepared from 4,4′‐bis(2‐methylphenoxy)diphenylsulfone and 4,4′‐bis(3‐methylphenoxy)diphenylsulfone with terephthaloyl chloride and isophthaloyl chloride by electrophilic Friedel‐Crafts acylation in the presence of DMF with anhydrous AlCl3 as a catalyst in 1,2‐dichloroethane, respectively. These polymers having weight‐average molecular weight in the range of 71,000–49,000 are all amorphous and show high glass transition temperatures ranging from 167 °C to 191 °C, excellent thermal stability at temperatures over 400 °C in air or nitrogen, high char yields of 51–58% in nitrogen and good solubility in CHCl3 and polar solvents such as DMF, DMSO and NMP at room temperature. 相似文献
20.
The radiation- induced polymerization of methyl vinyl ether under super-dry and wet conditions was studied. Little difference in the rates of polymerization was found. It seems clear that only an extremely slow free-radical polymerization was taking place. Possible reasons for the lack of concurrent cationic polymerization are discussed. 相似文献