Polyaddition between 2-alkenyl cyclic imino ether and mercaptocarboxylic acid

Summary A new polyaddition reaction between 2-alkenyl cyclic imino ether 1 and mercaptocarboxylic acid 2 was discovered. This polyaddition consists of two steps. The first reaction is the addition of a mercapto group of 2 to an activated carbon-carbon double bond of 1, which takes place at room temperature to produce the adduct 3. The second reaction is an intermolecular reaction between the carboxy group and the cyclic imino ether group with ring-opening which produces poly (amide-thioether-ester) 4.     

Reactivity and mechanism in the cationic polymerization of isobutyl vinyl ether

The cationic polymerization of isobutyl vinyl ether initiated by triphenyl methyl and tropylium hexachloroantimonates, and by triphenyl methyl tetrafluoroborate, has been studied in detail. Initiation was rapid and complete, termination was shown to be insignificant, polymerization half lives were of the order of 5–10 s and reaction rates were measured by an adiabatic calorimetric technique. Catalyst concentrations employed were sufficiently low that essentially complete dissociation into free ions is indicated by ion-pair dissociation constants, and this permits estimation of the rate coefficient for propagation by free cations (k_p). At 0°C in methylene dichloride k_p ∼ 5 × 10³ M⁻¹ s⁻¹, in substantial agreement with values obtained by radiation induced polymeirzation of bulk monomer. Molecular weights of the poly(isobutyl vinyl ether) samples fell in the range 2000–5000 on account of monomer transfer processes. Detailed mechanisms for initiation, propagation, transfer and termination reactions are considered.     

Synthesis of novel sulfonium salts and cationic polymerization of epoxides and vinyl ether

Novel 1‐methoxycarbonylethylmethylphenylsulfonium salts with nonnucleophilic anions, namely, hexafluorophosphate, hexafluoroantimonate, and tetrafluoroborate, were synthesized by the reaction of 1‐methoxycarbonylethylphenylsulfide and dimethyl sulfate followed by anion exchange with potassium hexafluorophosphate, sodium hexafluoroantimonate, and sodium tetrafluoroborate, respectively. The cationic polymerization (photopolymerization and thermal polymerization) of epoxy and vinyl ether monomers was carried out to demonstrate the applicability of the newly synthesized sulfonium salts. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3157–3163, 2007     

Polymerization via zwitterion 25. Alternating copolymerizations of cyclic acyl phosphorite and phosphite with vinyl monomers having an electron withdrawing group

Summary Spontaneous copolymerizations of cyclic acyl phosphonite (SPO) and phosphite (SPI) with an electron-deficient vinyl monomer such as methyl acrylate (MA), methyl vinyl ketone (MVK), and acrolein (AL), gave the corresponding alternating copolymers. These copolymerizations took place without added initiator and proceeded through zwitterion intermediates. Copolymer structures 1a, 1b, 2 and 3 have been established, all of which were derived in a regiospecific manner of ambident anions. The scheme of the copolymerizations is presented.     

Novel piperidinium salts as latent initiators for cationic polymerization of epoxide and vinyl ether

Novel dibenzylpiperidinium salts with nonnucleophilic anions (DBPi‐SbF₆, DBPi‐PF₆) have been prepared as latent cationic initiators. Utility of these salts in the photo and thermal‐induced cationic polymerizations of epoxide and vinyl ether monomer systems has been studied. The new initiator, DBPi‐SbF₆ showed good solubility, high reactivity, and high thermal latency for polymerizations of epoxide and vinyl ether monomers with only 1 wt % of concentration. Cationic polymerization of vinyl ether monomer was significantly faster than epoxide monomer by the synthesized initiators. This article describes the synthesis, characterization, and activity of novel initiators. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

管式反应器液相循环反应制备二甘醇乙烯基醚

以乙炔和二甘醇为原料,二甘醇钾为催化剂,采用管式反应器液相循环反应制备二甘醇乙烯基醚。研究了催化剂用量、反应温度、反应压力和停留时间等因素对乙炔转化率的影响,得到较为适宜的反应条件为：催化剂二甘醇钾用量为二甘醇质量的4%、反应温度175℃、反应压力6MPa、停留时间175s。在该条件下进行了液相连续循环反应,反应达到稳态时,二甘醇的转化率为76.03%,二甘醇单乙烯基醚收率为59.03%,二甘醇双乙烯基醚的收率为15.10%,合计二甘醇乙烯基醚总收率为74.13%。单位反应体积二甘醇乙烯基醚的产率为143.2g/（h·mL）。二甘醇与乙炔反应符合一级反应动力学方程,反应的指前因子k₀=1.20×10⁸s^–1,反应的活化能E=86.86kJ/mol。管式反应器中无气相乙炔,克服了高温高压下气相乙炔易燃易爆的危险。     

氯乙烯-异丁基乙烯基醚共聚物组成及性能

用核磁共振法表征了间歇乳液共聚合制备的氯乙烯一异丁基乙烯基醚(VC—IBVE)共聚物的结构．讨论了共聚物组成与性能的关系。结果发现,共聚物中VC摩尔分数随聚合转化率的增大而减小：共聚物组成对其在甲苯中的溶解性和溶液粘度有很大影响,当IBVE质量分数[ω(IBVE)]大于或等于13．9％时,共聚物可溶于甲苯;溶液粘度随ω(IBVE)的增大而减小;共聚物的玻璃化转变温度随ω(IBVE)的增大而降低．并符合Gordon—Taylor方程。     

AFM observations of silane coupling agent layers having a vinyl group deposited on a mica surface

The topography of silane layers deposited on an inorganic surface was observed using atomic force microscopy. For this purpose, cleaved mica plates were treated with some silane coupling agents at various conditions. Silanes having a vinyl group as the organic functional group with mono-, di- and trialkoxy structures were used. Four different solvents for silane solutions, 2-propanol, 2-propanol/water mixture, water and toluene, were used. The pH of the aqueous solution was controlled. As a result, the suitable solvent and pH were identified in order to obtain a smooth silane layer. The solubility of silane in the solution, the wettability of silane onto the inorganic surface and the depression of the self-condensation of silane molecules in the solution were found to be important parameters for this purpose.     

氯乙烯-异丁基乙烯基醚共聚树脂生产技术概述

介绍了国内外氯乙烯-异丁基乙烯基醚共聚树脂的生产技术现状,详细地比较了国内微悬浮法和乳液法两种工业生产技术的优缺点。     

Cationic photopolymerization of bisphenol-A-based vinyl ether systems

2,2-Bis{4-[2-(vinyloxy)ethoxy]phenyl}propane (BPA) monomer was synthesized and its cationic photopolymerization with triethyleneglycol divinyl-ether (DVE3) investigated. Real-time FT-IR kinetic investigations showed, in the presence of DVE3 monomer an increase of the photopolymerization rate and of the final vinyl ether double bond conversion.     

Living copolymerization of octadecyl vinyl ether with isobutyl vinyl ether: copolymerization parameters and crystallization behaviour of the copolymers

Cationic copolymerization of octadecyl vinyl ether (ODVE) with isobutyl vinyl ether (IBVE) under reaction conditions leading to living vinyl ether polymerization has been studied. The experimental results show that, under such conditions, the living nature of the copolymerization can be retained. The copolymerization parameters were found to be r_IBVE = 2.2 and r_ODVE = 0.30. Incorporation of up to 50% of IBVE units has only a small effect on the crystallinity of ODVE units. This is ascribed to the fact that the crystallinity is due to the octadecyl side‐chains and not to the main chain, and that the copolymers have a gradient‐like (tapered) structure. © 2000 Society of Chemical Industry     

Kinetic studies of the free cationic polymerization of ethyl vinyl ether and isobutyl vinyl ether initiated by triphenylmethyl hexachloroantimonate

The absolute rate constants for the cationic polymerization of ethyl and isobutyl vinyl ethers have been determined in methylene chloride solution. Under the conditions used, the polymerization proceeded by ‘free ions’. Extremely rigorous drying procedures were used and the values obtained were somewhat higher than those reported in the literature. The values were in reasonable agreement with the ‘free cation’ values obtained by a combination of rate and conductivity measurements of bulk polymerizations, initiated with gamma radiation under ‘super dry’ conditions. The activation energies were also in good agreement.     

Photocrosslinking reactions of polyfunctional monomers with vinyl ether or propargyl ether groups

Photocrosslinking reactions of di(2-vinyloxy)ethyl ether of bisphenol-A (BPAEVE), dipropargyl ether of bisphenol-A (BPAPE), and diglycidy ether of bisphenol-A (BPAGE) were carried out using various cationic photoinitiators in 1,2-dichloroethane. The reaction of BPAEVE occurred with high conversion to give the gel products, and the reaction rate of BPAEVE was higher than that of BPAGE. While, the photocrosslinking reaction of BPAPE did not take place under the same conditions. Photoinitiated Michael addition reactions of BPAEVE, BPAPE, and other dipropargyl ethers or ester with pentaerythritol (2-tetramercapto)propionate (PETMP) also proceeded very smoothly to give the gel products by using benzophenone as a photosensitizer in THF. Although the rate of addition reaction of BPAEVE was strongly influenced by the photosensitizer concentration, the addition reaction of BPAEVE with PETMP propagated effectively to give the gel products even without the presence of photosensitizer when irradiated with UV light in THF or toluene solution.     

Synthesis of cyclic precursors of poly(ether ether ketone)

Summary A novel synthetic route to cyclic PEEK precursors is described. These new cyclic oligomers have been prepared from hydroquinone and N-phenyl(4,4′-difluorodiphenyl) ketimine. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) analysis unambiguously confirmed the cyclic nature. Received: 7 December 1998/Revised version: 21 January 1999/Accepted: 29 January 1999     

氯乙烯-乙烯基异丁基醚共聚树脂黏度的影响因素

讨论了乙烯基异丁基醚含量、转化率、氯乙烯单体初始加入量、聚合温度对氯乙烯-乙烯基异丁基醚共聚树脂黏度的影响规律.     

四氟乙烯-全氟丙基乙烯基醚共聚物结构和性能

采用广角X射线衍射和差示扫描量热法研究了不同组成的四氟乙烯-全氟丙基乙烯基醚（TFE-PPVE)共聚物的结晶结构、结晶度和结晶熔融温度,结果发现,当共聚物中γ(PPVE)由0．48％增大到4．02％时,晶粒尺寸从87．2nm减小到22．0nm,同时结晶度和结晶熔融温度明显降低,熔体流动速率增大,尤其当γ(PPVE)大于2．5％时,增大显著。     

The adhesive properties of hydantoin vinyl ether polymers

The hydantion vinyl ether polymers are alternating copolymers of 3-vinyloxyethyl-5,5-dimethylhydantion (HVE) and maleic anhydride (MA). The adhesive properties of HVE/MA and structurally related polyvinyl pyrrolidone (PVP) and methylvinylether/maleic anhydride (MVE/MA) polymers were compared on an approximately 1:1 specific viscosity basis. Lap shear strength measurements showed approximately 10:1 and 4:1 ratios in favor of the HVE/MA polymers as compared to PVP and MVE/MA, respectively. These differences are possibly due to the higher cohesive strength of the HVE/MA repeating unit and to the fact that this polymer would appear to contain more structural elements liable to make physical and chemical contributions to the interfacial attachment strength. Based on these preliminary results, HVE/MA and MVE/MA polymers with identical specific viscosities were applied to carbon pitch fiber via electrodeposition. Using the standard MY 720/DDS epoxy laminating system for advanced composite applications 36% and 13% improvements in interlaminar shear strength were observed for an add-on of 2%.     

二甲醚催化氧化合成醋酸乙烯

通过浸渍法制得负载型H_4SiW_(12)O_(40)-MoO_3/SiO_2催化剂,并在连续流动同定床反应装置上考察了其在二甲醚催化氧化合成醋酸乙烯的催化活性,研究了反应压力和助催化组分改性催化剂对二甲醚催化氧化合成醋酸乙烯的影响.结果表明,当原料气配比为n(DNE):n(O_2):n(Ar)=1.5:1:1,反应压力为0.25 MPa,CoO改性H_4SiW_(12)O_(40)-MoO_3/SiO_2催化剂催化氧化二甲醚合成醋酸乙烯的选择性由3.69%提高至7.09%,二甲醚的转化率由55.20%增加至61.18%.X射线衍射结果表明,CoO能促进MoO3和U_4SiW_(12)O_(40)在SiO_2载体表面上均匀分布.NH3程序升温脱附结果显示,添加氧化钴助催化组分能进一步调变H_4SiW_(12)O_(40)MoO_3/SiO_2催化剂表面酸性.