Functional Acetal Methacrylates: III. Electrophilic Addition of Diols to 2-(Vinyloxy)ethyl Methacrylate

Reactions of 2-(vinyloxy)ethyl methacrylate with diols [ethylene glycol, diethylene glycol, triethylene glycol, oligoethylene glycol-400, Z-2-butene-1,4-diol, 2-butyne-1,4-diol, 1,1,3,3-tetramethyl-1,3-bis(3-hydroxypropyl)disiloxane, 2,2-bis(4-hydroxyphenyl)propane] and polyols (glycerol, pentaerythritol) under electrophilic conditions (1 wt% of CF₃COOH, 20-60°C, 1-3 h) result in quantitative formation of functional acetal methacrylates.     

The flammability properties of copolyesters and copolycarbonates containing acetylenes

The flammability properties of copolyesters and copolycarbonates containing varying percentages of 2-butyne-1,4-diol and 2,4-hexadiyne-1,6-diol were studied by use of oxygen index and dynamic thermogravimetry. The char formation was found to increase with increasing polymer unsaturation. For nonconjugated acetylenes there is an increase in the oxygen index with increasing unsaturation in a polymer. In contrast, conjugated acetylenes dramatically decrease the oxygen index of a polymer system.     

一种简便合成2-丁炔-1,4-二醇衍生物的新方法

由2-丁炔-1,4-二醇可以很方便地得到2-丁炔-1,4-二氯,这一试剂在有机合成中有着广泛的应用。而在其它条件相同的情况下,制备2-丁炔-1,4-二溴并未得到相应较好的结果。我们用无水苯为反应溶剂,以温和的 (PPh3)PBr2作为卤代试剂(冰浴下液溴逐滴滴入PPh3苯溶剂中当场生成)卤化2-丁炔-1,4-二醇,选择性合成得到2-丁炔-1,4-二溴衍生物。同时也实现了2-丁炔-1,4-二醋酸酯的合成。     

A chemical study of 2-butyne-1,4-diol

Commercial grade 2-butyne-1,4-diol has been used in electroplating for several years. In laboratory experiments, its presence in the electrolyte increases the current efficiency of zinc electro-winning. Its chemical behaviour in solution is not well known. The present paper indicates that the brownish technical grade 2-butyne-1,4-diol contains the monomer, the dimer and some trimer. Pure monomeric 2-butyne-1,4-diol is a white solid obtained by evaporation of the technical grade product. The monomer is slowly transformed into dimer and possibly into a trimer when dissolved in water. Various analytical techniques were used in the study of this system. Factor analysis with column cross-validation was applied to chromatographic data to help in the resolution of the system.     

Procedures for recovery of crystalline 2-butyne-1,4-diol from industrial aqueous solutions and for its purification

Four procedures for recovery of crystalline 2-butyne-1,4-diol from aqueous solutions and for its purification were examined. Samples of crystalline 2-butyne-1,4-diol containing 98.5 to 99.9 wt % target product were obtained.     

Catalytic hydrogenation of 2-butyne-1,4-diol to 2-butene-1,4-diol at atmospheric pressure in the liquid phase

Selective hydrogenation of 2-butyne-1,4-diol to 2-butene-1,4-diol on suspended palladium and Raney nickel catalysts at atmospheric pressure was studied. The optimal parameters of this reaction were determined. Samples containing 90% 2-butene-1,4-diol were prepared.     

Thermal and pyrolysis studies of copolyesters

Random copolyesters of dimethyl terephthalate (DMT), ethylene glycol (EG), and butane-1,4-diol (BD) and the homopolyesters poly(ethylene terephthalate) (PET) and poly(butylene terephthalate) (PBT) have been subjected to degradation and pyrolysis studies. Differential thermal analysis (DTA) showed that the decomposition temperature is dependent on the percentage of EG and BD present in the copolyesters. Thermal volatilization analysis (TVA) also showed that the decomposition temperature is dependent on the percentage of EG and BD present in the copolyesters. The trend for the decomposition temperatures obtained from TVA studies for these copolyesters is similar to such other thermal properties as melting temperature T_m, ΔH_f, ΔH_c, etc. The subambient thermal volatilization analysis (SATVA) curves obtained for these polymers are also presented. The SATVA curve is the fingerprint of the total volatile products formed during the degradation in high vacuum. The isothermal pyrolysis of these materials was carried out in high vacuum at 450°C. The products formed were separated in a gas chromatograph and were subsequently identified in a mass spectrometer. The major pyrolysis products from PBT were butadiene and tetrahydrofuran, whereas those from PET were ethylene and acetaldehyde. The ratio of acetaldehyde to ethylene increases with the EG content in the copolyester, suggesting a different decomposition mechanism compared to the decomposition mechanism of PBT and PET.     

Determination of 2-Butyne-1,4-Diol Dioxyethyl Ether in Nickel-Plating Electrolytes

A procedure was developed for determining 2-butyne-1,4-diol dioxyethyl ester in nickel-plating electrolytes in the presence of hydrogenation products. The difference in the bromination capacity of ethylene and acetylene bonds forms a basis for the direct potentiometric titration of ethylene hydrogenation products with potassium bromate and the back titration of excess bromate after the bromination of acetylene compounds. The relative error of determination was no worse than 4%.     

Reductive cleavage of C-OH bonds in allyl position-formation of gaseous products in the course of the cathodic reduction of some simple unsaturated alcohols

The problem of the reductive cleavage of C?OH bonds in allyl position has been considered starting from the literature data concerning the behaviour of allyl alcohol. The formation of hydrocarbons has been shown in the case of the electroreduction of crotyl alcohol, 2-butene-1,4-diol, propargyl alcohol, 2-butyne-1,4-diol and 1-butyne-3-ol. The composition of the gaseous products was analyzed, current efficiency values with respect to the hydrocarbon formation were calculated. Schemes for the reduction path were given.     

主链含酰亚胺环和炔基的聚酰亚胺型聚氨酯弹性体的合成及阻燃性能

以均苯四甲酸酐、 D,L-苯丙氨酸和1,4-丁炔二醇为原料合成了一种含有酰亚胺环和炔基的二醇, 并以其为扩链剂, 采用预聚体法, 与4,4-二苯基甲烷二异氰酸酯(MDI)和聚四氢呋喃醚二醇(PTMG)反应, 合成了不同硬段含量的主链含有酰亚胺环和炔基的热塑性聚酰亚胺型聚氨酯弹性体. 用红外光谱(FTIR)、 电子拉力机、 热失重分析(TG)、 广角X射线衍射(XRD)、 UL-94垂直燃烧和极限氧指数对聚酰亚胺型聚氨酯弹性体进行了表征. 结果表明, 这种聚氨酯呈现出无定形结构; 其拉伸强度随着硬段含量的增加而增大; 与传统的热塑性聚氨酯相比, 酰亚胺环和炔基改性的聚酰亚胺型聚氨酯弹性体的热分解过程非常缓慢, 呈现出较好的热稳定性; 不同硬段含量的聚酰亚胺型聚氨酯弹性体的UL-94垂直燃烧均达到V-2级别; 其极限氧指数随着硬段含量的增加而增大.     

主链含酰亚胺环和炔基的聚酰亚胺型聚氨酯弹性体的合成及阻燃性能简

以均苯四甲酸酐、D,L-苯丙氨酸和1,4-丁炔二醇为原料合成了一种含有酰亚胺环和炔基的二醇,并以其为扩链剂,采用预聚体法,与4,4-二苯基甲烷二异氰酸酯(MDI)和聚四氢呋喃醚二醇(PTMG)反应,合成了不同硬段含量的主链含有酰亚胺环和炔基的热塑性聚酰亚胺型聚氨酯弹性体. 用红外光谱(FTIR)、电子拉力机、热失重分析(TG)、广角X射线衍射(XRD)、UL-94垂直燃烧和极限氧指数对聚酰亚胺型聚氨酯弹性体进行了表征. 结果表明,这种聚氨酯呈现出无定形结构;其拉伸强度随着硬段含量的增加而增大;与传统的热塑性聚氨酯相比,酰亚胺环和炔基改性的聚酰亚胺型聚氨酯弹性体的热分解过程非常缓慢,呈现出较好的热稳定性;不同硬段含量的聚酰亚胺型聚氨酯弹性体的UL-94垂直燃烧均达到V-2级别;其极限氧指数随着硬段含量的增加而增大.     

Potentialities of the Voltammetry of 2-Butyne-1,4-diol at Mechanically Renewed Solid Electrodes

The electrochemical behavior of 2-butyne-1,4-diol was studied at solid platinum, gold, silver, cobalt, nickel, copper, and graphite electrodes. The working surfaces of the electrodes were renewed by cutting a thin 0.5-µm layer in the test solution immediately before recording every voltammogram. 2-Butyne-1,4-diol was oxidized in alkaline solutions at graphite, nickel, silver, and copper electrodes at positive potentials; the voltammograms obtained at these electrodes were suitable for analytical purposes. The dependence of the anodic current of 2-butyne-1,4-diol on its concentration was linear in the range from 0.03 to 0.3 g/L.__________Translated from Zhurnal Analiticheskoi Khimii, Vol. 60, No. 5, 2005, pp. 499–503.Original Russian Text Copyright © 2005 by Skvortsova, Aleksandrova, Kiryushov.     

Electrolytic reduction of 2-butyne-1,4-diol as a route to trans-2-butene-1,4-diol

The effect of the cathode material on the electrochemical transformations of 2-butyne-1,4-diol at atmospheric pressure was studied by chromatographic analysis. The optimal parameters of the selective synthesis of trans-2-butene-1,4-diol were determined.     

Analysis of products from hydrogenation of 2-butyne-1,4-diol

Conclusions A qualitative and quantitative method has been developed for analysis of a mixture of butane-1,4-diol, cis-2-butene-1,4-diol, trans-2-butene-1,4-diol, and 2-butyne-1,4-diol in the form of their diacetates by gas chromatography.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 942–944, April, 1970.     

Raman-spectrum investigation of 2-butyne-1,4-diol 2-butyne-1,4-diol diacetate,and 1,4-dichloro-2-butyne

Summary 2-Butyne-1,4-diol, 2-butyne-1,4-diol diacetate, and 1,4-dichloro-2-butyne exist in cisoid and transoid forms because of the operation of factors hindering free rotation of individual groups of atoms in these molecules around the corresponding single bonds.     

Novel copolyesters containing naphthalene structure. II. Copolyesters prepared from 2,6-dimethyl naphthalate, 1,4-dimethyl terephthalate,and ethylene glycol

Copolyesters containing rigid segments (naphthalene and terephthalene) and flexible seg-ments (aliphatic diol) structure were synthesized from DMN/DMT/EG (2,6-dimethyl naphthalate/1,4-dimethyl terephthalate/ethylene glycol) ternary monomers with various mole ratios. Copolyesters having intrinsic viscosities of 0.52–0.65 dL/g were obtained by melt polycondensation in the presence of metallic catalysts. The effect of reaction tem-perature and time on the formation of the copolyesters was investigated to obtain an op-timum condition for copolyester manufacturing. The optimum condition for PNT (poly-ethylene naphthalate terephthalate) copolyester manufacturing is the transesterification under nitrogen atmosphere for 4 h at a temperature of 185±2°C followed by polymerization under 2 mm Hg for 2 h at a temperature of 280°C. Most copolyesters have better solubilities than poly(ethylene naphthalate) (PEN) and poly(ethylene terephthalate) (PET) in various solvents. The effect of the starting mole ratio of DMN, DMT, and EG on the thermal properties of the resulted copolyesters was also investigated using differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). Glass transition temperatures of copolyesters were in the range of 70.7–115.2°C, and 10% weight loss in nitrogen were all above 426°C. © 1995 John Wiley & Sons, Inc.     

Liquid-phase catalytic hydrogenation of 2-butyne-1,4-diol to 1,4-butanediol at atmospheric pressure on suspended catalysts

The optimum parameters of hydrogenation of 2-butyne-1,4-diol to 1,4-butanediol on the suspended palladium and Ni-Raney catalysts at atmospheric pressure were found. In selected conditions a yield up to 90% of 1,4-butanediol was reached.     

Rearrangement of 2-butyne-1,4-diol to butyrolactone catalyzed by ruthenium complexes

The isomerization of 2-butyne-1,4-diol to butyrolactone catalysed by ruthenium complexes is described.     

Ionization constants for water and for very weak organic acids in aqueous organic mixtures

A potentiometric method using a glass electrode has been applied to the determination of apparent ionization constants for water in binary mixtures of water with 11 organic solvents at 25°C. Further calculations with these apparent ionization constants permit evaluation of the acid ionization constant for some of the organic solvents as solutes in purely aqueous solvent by two different methods. Resulting values of pK _a derived from this work are: 1,2-propanediol (14.8 and 14.8), 2,3-butanediol (15.0 and 14.7), 1,3-butanediol (15.5 and 14.8), 1,4-butanediol (14.5 and 14.4), 2-butene-1,4-diol (14.0 and 13.9), 2-butyne-1,4-diol (12.1 and 12.4), 2-methoxyethanol (15.2 and 14.8), 2-ethoxyethanol (15.0 and 14.5), and triethylene glycol (14.6 and 14.3). None of the 11 solvents shows appreciable basicity.     

Thermotropic copolyesters. II. Synthesis and characterization of copolyesters containing the bicyclo[2.2.2]oct-2-ene mesogenic unit

Random copolyesters based on 1,4-benzenedimethanol, trans-1,4-cyclohexanedimethanol, and 1,4-bicyclo[2.2.2]octanedimethanol as spacers in ratios of 2 : 3 of the mesogenic group, bicyclo[2.2.2]oct-2-ene-1,4-diol were prepared and characterized. The copolyesters containing the 1,4-benzenedimethanol moiety formed a more brightly colored birefringent fluid in the melt.