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1.
Free radical-initiated copolymerization of diethyl vinyl phosphate (DEVPA) with vinyl acetate (VAc) and acrylonitrile (AN) was studied. The monomer reactivity ratios for the monomer pairs, determined at 60°C using benzoyl peroxide as an initiator, are: r1(VAc) = 0.95, r2(DEVPA) = 0.93; r1(AN) = 6.6, r2(DEVPA) = 0.049. The values of the Alfrey-Price constants, Q and e, for DEVPA were calculated to be 0.025 and 0.13, respectively, from the VAc system, and 0.026 and 0.14, respectively, from the AN/DEVPA pair. These results indicate that the general reactivity of DEVPA is almost the same as that of VAc and that the diethylphosphate group is a stronger electron-attracting group than the acetoxy group. The intrinsic viscosity and number-average molecular weight of copolymers decreased as their content of DEVPA units increased, indicating a high degree of chain transfer caused by DEVPA. 相似文献
2.
Cyclopropanation of vinyl sulfones and vinyl sulfides can be achieved by phase transfer catalysis where other cyclopropanation methods have failed. 相似文献
3.
Electret properties of vinyl chloride/vinyl acetate copolymer and its composites with zinc oxide are studied.__________Translated from Zhurnal Prikladnoi Khimii, Vol. 78, No. 3, 2005, pp. 502–505.Original Russian Text Copyright © 2005 by Galikhanov, Deberdeev. 相似文献
4.
Conclusion The alkylation of trimethylamine by O-phosphorylated allyl chloride gave a new type of choline phosphate, namely, a vinylcholine phosphate. The thermal dealkylation of this product gave a phosphorus-containing betaine.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khitnicheskaya, No. 10, pp. 2333–2334, October, 1986. 相似文献
5.
Kiyokazu Imai Tomoo Shiomi Yasuyuki Tezuka Keizo Takahashi 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(10):1347-1358
The homopolymerization of a series of alkyl vinyl sulfoxides (CH2[dbnd]CHSOR; R = CH3 (MVSO), C2H5 (EVSO), t-C4H9 (BVSO)) and their copolymerization with vinyl acetate (VAc) with 2,2′-azobisisobutyronitrile (AIBN) as initiator at 60°C was attempted. MVSO was found to homopolymerize radically, but EVSO and BVSO were not. Poly-MVSO is soluble in chloroform, methanol, DMSO, and water, but insoluble in acetone and benzene. MVSO and EVSO were found to copolymerize with VAc, but BVSO was not. The copolymerization parameters obtained for both systems were as follows; r1(MVSO) = 2.23, r2 (VAc) = 0.09, and r1(EVSO) = 3.40, r2 (VAc) = 0.11, respectively. MVSO/vinyl alcohol (VA) copolymers were obtained through the saponification of MVSO/VAc copolymers by sodium hydroxide in methanol. The solubility of MVSO/VAc and of MVSO/VA copolymers toward various solvents was examined, and it was observed that the sulfoxide comonomer has a tendency to give amphiphilicit to poly(vinyl acetate) and poly(vinyl alcohol). The 24 mol% MVSO containing VAc copolymer is soluble in both benzene and water. 相似文献
6.
Jessica H. Wong Marilyn M. Olmstead James C. Fettinger Jacquelyn Gervay‐Hague 《Acta Crystallographica. Section C, Structural Chemistry》2008,64(3):o132-o136
Four neutral vinyl sulfones, two of which are paired with phosphonate groups, are described. The compounds are diisopropyl (2‐phenylethenylsulfonylmethyl)phosphonate, C15H23O5PS, (I), diisopropyl {[2‐(7‐methoxy‐1,3‐benzodioxol‐5‐yl)ethenylsulfonyl]methylsulfonylmethyl}phosphonate, C18H27O10PS2, (II), bis(trans‐2‐phenylethenyl) sulfone, C16H14O2S, (III), and bis(trans‐2‐phenylethenylsulfonyl)methane, C17H16O4S2, (IV). Their structures can be considered as highly functionalized mimics of mono‐, di‐ and triphosphates. These phosphate isosteres are currently of interest as agents for enzyme inhibition in both cancer and HIV therapy. All except one of the compounds has Z′ > 1. The lone exception is (IV), a disulfone with twofold crystallographic symmetry. Geometrically, the sulfone functionality is found to be a good mimic for phosphate. The principal effect of the vinyl group is to shorten the S—C(vinyl) distance relative to the S—CH2 distance by ca 0.05 Å. The S—C—S and S—C—P backbones resemble the P—O—P backbone but are not identical because the S—C and P—C distances are longer than the P—O distance and the S—C—S and S—C—P angles are more acute than the P—O—P angle. No prior crystal structures of comparable compounds have been published. 相似文献
7.
Andrey A. Fokin Ekaterina D. Butova Anastasiya V. Barabash Nhan N. Huu Boryslav A. Tkachenko Natalie A. Fokina 《合成通讯》2013,43(13):1772-1777
We describe a convenient four-step preparation of 1- vinyl adamantane, 1- vinyl diamantane, and 4,9-divinyl diamantane from the respective diamondoid acetic acids in 50–80% isolated yields involving esterification, reduction, and hydrobromination/dehydrobromination. Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications® to view the free supplemental file. 相似文献
8.
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
9.
The kinetics of the aqueous polymerization of acrylonitrile and methyl methacrylate initiated by the peroxydiphosphate-thioglycollic acid redox system was investigated at 40, 45, 50, 55, and 60 °C. The rates of polymerization were measured at different concentrations of oxidant, activator and monomer. From the results, it was concluded that the polymerization reaction is initiated by an organic free radical arising from the peroxydiphosphate-thioglycollic acid system and termination by mutual type. On the basis of experimental observations of the dependence of the rate of polymerization,R
p on various variables, a suitable kinetic scheme has been proposed. 相似文献
10.
A series of vinylimidazoles were synthesized via Wittig reactions on N-tritylimidazole-4-carboxaldehyde. Activated phosphonate ylids afforded yields in excess of 90% while the yields from unactivated ylids ranged from 10–82%. The trityl group may be removed by mild acid hydrolysis in high yield. 相似文献
11.
B. Terwiesch 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(7):1081-1092
The formation of polymer peroxides by the addition of oxygen to unsaturated organic compounds was described for the first time by Staudinger, taking 1,l-diphenyl ethylene peroxide as an example [1]. In the meantime, numerous other polyperoxides have become known, among them the peroxides of acrylonitrile [2], dimethyl butadiene [3], chloroprene 141, methyl methacrylate 51, styrene 161, vinyl acetate [5], and vinyl chloride [7-10]. Because of the great significance of the aforementioned compounds as monomers in the production of plastic materials, the investigations centered on the influence of oxygen on the polymerization behavior of the monomers and on the properties of the polymers. 相似文献
12.
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, ez = ?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. 相似文献
13.
Sebastian Schroeder Christina Strauch Niklas Gaelings Meike Niggemann 《Angewandte Chemie (International ed. in English)》2019,58(15):5119-5123
A new concept for selectivity control in carbocation‐driven reactions has been identified which allows for the chemo‐, regio‐, and stereoselective addition of nucleophiles to alkynes—assisted vinyl cation formation—enabled by a Li+‐based supramolecular framework. Mechanistic analysis of a model complex (Li2NTf2+?3 H2O) confirms that solely the formation of a complex between the incoming nucleophile and the transition state of the alkyne protonation is responsible for the resulting selective N addition to the vinyl cation. Into the bargain, a general, operationally simple synthetic procedure to previously inaccessible vinyl triflimides is provided. 相似文献
14.
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
15.
Shubha Maudgal 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(5):631-638
Vinyl cinnamate (C) was synthesized and copolymerized with vinyl acetate (A) in benzene at 60° using benzoyl peroxide as initiator. Monomer distributions in the resulting copolymers were determined by the infrared spectral technique. A calibration curve was obtained for this purpose. Reactivity ratios as calculated by Kelen and Tüdös method were found to be rC= 1.401 ± 0.210, rA. = 0.043 ± 0.006. 相似文献
16.
顶空气相法测定氯乙烯生产过程产生的盐酸溶液中的乙炔和氯乙烯 总被引:3,自引:0,他引:3
采用顶空气相法测定了氯乙烯生产过程产生的盐酸溶液中的乙炔和氯乙烯。使用氢氧化钠将试样中的氯化氢中和 ,从而消除其在气相分析乙炔和氯乙烯中的影响。顶空平衡温度为 35℃ ,平衡时间为 4 5min ,柱为填充了GDX 2 0 2固定相的 2m× 3mmi d 不锈钢柱 ,柱温 14 0℃。顶空气体进样量为 1mL。以外标法定量 ,乙炔含量测定结果的相对标准偏差为 0 85 % ;当其含量为 30 0 μg/g~ 15 0 μg/g时 ,回收率为 98 9%~10 3%。氯乙烯含量测定结果的相对标准偏差为 1 4 % ;当其含量为 2 0 0 μg/g~ 10 0 μg/g时 ,回收率为 98 8%~10 2 %。 相似文献
17.
Several nonracemic diols and amino alcohols have been tested for their utility as chiral auxiliaries in vinyl phosphate/beta-keto phosphonate rearrangements. When (2R,4R)- or (2S,4S)-pentane-2,4-diol were employed, the diastereomeric beta-keto phosphonates obtained from three prochiral cyclohexanones gave separate resonances in their respective (31)P NMR spectra, allowing estimation of diastereomeric excess (de) via straightforward integration. A crystalline enol form of the beta-keto phosphonate was obtained from one ketone (4-(1,1-(ethylenedioxy)ethyl)-4-methylcyclohexanone, 10), which allowed determination of its absolute stereochemistry by X-ray diffraction analysis. When LTMP was used to induce rearrangement of vinyl phosphates derived from ketone 10 and (2R,4R)- or (2S,4S)-pentane-2,4-diol, a de of 2.5:1 was obtained. In addition, de values of 2.0:1 and 1.4:1 were obtained with parallel rearrangements of 4-isopropyl- and 4-methylcyclohexanone, suggesting that this sequence may be more generally applicable to preparation of nonracemic materials from prochiral cyclohexanones. 相似文献
18.
Padma L. Nayak 《高分子科学杂志,C辑:聚合物评论》2013,53(2):267-296
Polymer chemists have been successful in applying polymerization techniques to develop copolymers of natural and synthetic macromolecules [l]. The literature abounds with examples of the successful formation of copolymers from natural and synthetic macromolecules [2–5]. Copolymerization is attractive to chemists as a means of modifying macromolecules since, in general, degradation can be minimized. Despite the heterogeneity and complexity of these copolymers, much has been achieved in their characterization. The desirable properties of the polymer are retained and additional properties are acquired through the added polymer. The desired material may be formed in situ by polymerization of a monomer or monomers, by condensation of reactants, or by the decomposition of a preformed polymer. 相似文献
19.
M. Ravey J. A. Waterman L. M. Shorr M. Kramer 《Journal of polymer science. Part A, Polymer chemistry》1976,14(7):1609-1616
Because of the allylic nature of propylene, the vinyl chloride–propylene system exhibits polymerization behavior markedly different from that of vinyl chloride, even at relatively low propylene concentrations. Propylene acts as a degradative chain-transfer agent, and as a result, both the polymerization rate and the molecular weight of the resultant copolymers are lower than those of the homopolymer, decreasing with increasing propylene content. Even at propylene concentrations as low as 10% the rate of polymerization is proportional to the initiation rate, indicating kinetic control by the propylene. The reactivity ratios of these monomers given by Cain were verified. The reciprocal intrinsic viscosity of the copolymer was found to be linearly related to the monomer feed composition. 相似文献