Liquid crystalline polyesteramides containing crown ether units in the mesogenes

Main chain liquid crystalline polyesteramides containing dibenzo-[18]-crown-6 moieties have been synthesized. Shown by polarisation microscopy and x-ray investigations, these polymers tend to form a mesophase with a layered structure,e.g. smectic A or smectic C type.     

液晶冠醚的合成及在分析化学中的应用

讨论了近年来液晶冠醚的合成方法及其性质，并总结了其离子传输，分子识别以及在色谱分析，LB膜等方面的应用。     

开链冠醚衍生物的合成

开链冠醚基二芳醛在酸性条件下与氨基脲反应,合成了链状二芳醛缩氨脲类化合物,产率高达90%以上,产物由IR、MS和元素分析鉴定了其结构。     

冠醚化学研究的新进展

介绍了冠醚类化合物的结构特点及络合性能、冠醚的络合作用和识别分子离子的新进展。重点综述了近几年各类新冠醚化合物的合成、配合物的形成、对分子离子的识别、选择性络合及新应用,展望了其广阔的应用前景,期望能在医药学、生命科学、材料科学、环境科学及能源科学的应用方面更有意义。     

新型冠醚交联壳聚糖的合成

利用壳聚糖C2位上活泼氨基与苯甲醛反应,制得了保护氨基的Schiff碱壳聚糖（简称CTB）;再将合成的带有双活性基团的4,4‘-二溴二苯并18-冠-6冠醚与壳聚糖分子的羟基发生反应,得到二苯并18-冠-6冠醚交联的Schiff碱壳聚糖（简称CTBD）,在酸性条件下使CTBD脱去苯甲醛,制得二苯并18-冠-6冠醚交联壳聚糖（简称CTD）。其主要中间体及产物的结构经红外光谱、质谱、核磁共振动等进行了鉴定。     

Novel sulfonated poly(ether ether ketone ketone) derived from bisphenol S

A series of sulfonated poly(ether ether ketone ketone)s derived from bisphenol S were prepared by nucleophilic polycondensation. They showed high thermal resistance and good solubility. Most of the polymers were easily cast into tough membranes. The swelling of the membranes (6.02–16.02%) was lower than that of Nafion membranes, and the ion‐exchange capacity of the membranes (0.67–1.44) was higher than that of Nafion membranes. The proton conductivity of the membranes was 0.022–0.125 s/cm. They could be used as proton‐exchange membranes in fuel cells. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1569–1574, 2004     

卟啉环系冠醚的超声波合成

通过采用超声波方法合成了1,1,6,6,11,11,16,16-八甲基-21,22,23,24-四氧杂夸忒烯,产物的结构通过红外光谱和核磁共振等方法确证.结果表明,超声波合成方法最佳反应条件:20℃下超声5h,产率37.31%.     

Modification of phenolic resins containing crown ether units

Summary Phenolic resins containing 13-crown-4 and 9-crown-3 units (1) were modified by coupling and nitration in heterogeneous phase. The chromogenic resins extract Li⁺ selectively and efficiently, and no extractions of Na⁺ were found. The extractions were carried out with aqueous solutions of lithium and aqueous solutions of sodium chloride at pH=7 and 11. Finally, re-extraction analysis of lithium in methanol and water were made. Resins release partially the cation. Major re-extraction was obtained with methanol.     

Ordered macroporous films from self-assembly of two-armed polymer with a crown ether core

Highly ordered honeycomb-like macroporous films were obtained via self-assembly of a two-armed polymer with a crown ether core under controlled conditions. A possible mechanism is speculated, primarily based on the strong affinity between the crown ether cores. The pore size and arrangement are sensitive to the solvent evaporation rate and the solution concentration. Upon spontaneous drying, the pore diameter (D) depends on the concentration (c) by a relation of D=518c^−0.610.     

Liquid phase methanol and dimethyl ether synthesis from syngas

The Liquid Phase Methanol Synthesis (LPMeOH^TM) process has been investigated in our laboratories since 1982The reaction chemistry of liquid phase methanol synthesis over commercial Cu/ZnO/Al₂O₃ catalysts, established for diverse feed gas conditions including H₂-rich, CO-rich, CO₂-rich, and CO-free environments, is predominantly based on the CO₂ hydrogenation reaction and the forward water-gas shift reactionImportant aspects of the liquid phase methanol synthesis investigated in this in-depth study include global kinetic rate expressions, external mass transfer mechanisms and rates, correlation for the overall gas-to-liquid mass transfer rate coefficient, computation of the multicomponent phase equilibrium and prediction of the ultimate and isolated chemical equilibrium compositions, thermal stability analysis of the liquid phase methanol synthesis reactor, investigation of pore diffusion in the methanol catalyst, and elucidation of catalyst deactivation/regenerationThese studies were conducted in a mechanically agitated slurry reactor as well as in a liquid entrained reactorA novel liquid phase process for co-production of dimethyl ether (DME) and methanol has also been developedThe process is based on dual-catalytic synthesis in a single reactor stage, where the methanol synthesis and water gas shift reactions takes place over Cu/ZnO/Al₂O₃ catalysts and the in-situ methanol dehydration reaction takes place over -Al₂O₃ catalystCo-production of DME and methanol can increase the single-stage reactor productivity by as much as 80%. By varying the mass ratios of methanol synthesis catalyst to methanol dehydration catalyst, it is possible to co-produce DME and methanol in any fixed proportion, from 5% DME to 95% DMEAlso, dual catalysts exhibit higher activity, and more importantly these activities are sustained for a longer catalyst on-stream life by alleviating catalyst deactivation.     

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     

Poly(arylene ether sulfones) and poly(arylene ether ketones) derived from dibenzofuran

Summary New polyarylene ether ketones and polyarylene ether sulfones were prepared by polycondensation of various bisphenols with two new dihalide monomers including dibenzofuran structure, respectively 3,6 bis (4-fluorophenylcarbonyl) dibenzofuran and 3,6 bis (4-fluorophenylsulfonyl) dibenzofuran. Most of these thermoplastic polyethers are soluble in NMP and in chlorinated soluents. They exhibit Tgs up to 234°C for the polyetherketones and up to 262°C for the polysulfones, so over 50°C higher than the Tgs of classical available polyethers.     

Anionic ring-opening polymerization of five-membered cyclic carbonates derived from aldohexopyranosides

Polymer Bulletin - To investigate the relationship between the steric structures and polymerizability of five-membered cyclic carbonates, the anionic ring-opening polymerizations of methyl...     

Preparation of macroporous silica-based crown ether materials for strontium separation

To develop a separation process of Sr(II), a macroporous silica-based 4,4′,(5′)-di(tert-butylcyclohexano)-18-crown-6 (DtBuCH18C6) polymeric material, (DtBuCH18C6+Oct)/SiO₂-P, was synthesized by impregnating and immobilizing DtBuCH18C6 and 1-octanol into the pores of the macroporous SiO₂-P particles support. DtBuCH18C6 was modified with 1-octanol through hydrogen bonding. The adsorption of simulant elements of some typical fission products Ru(III), Pd(II), Ba(II), Mo(VI), La(III), Y(III), Sr(II), Cs(I) and those of non-fission products Na(I) and K(I) onto (DtBuCH18C6+Oct)/SiO₂-P were studied at 298 K. The effects of the HNO₃ concentration in a range of 0.1–5.0 M and contact time on the adsorption were investigated. (DtBuCH18C6+Oct)/SiO₂-P showed excellent adsorption ability and high selectivity for Sr(II) over all of the tested metals except Ba(II). Partitioning of Sr(II) from a 2.0 M HNO₃ solution containing ~5.0 × 10^?3 M of the tested metals was conducted utilizing (DtBuCH18C6+Oct)/SiO₂-P packed column. Pd(II), Mo(VI), Y(III), La(III), Ru(III), K(I), Cs(I), and Na(I) showed no adsorption and flowed into effluent along with 2.0 M HNO₃. Sr(II) was retained on (DtBuCH18C6+Oct)/SiO₂-P and was eluted effectively by H₂O, while Ba(II) showed similar elution behavior. The bleeding of total organic carbon leaked from (DtBuCH18C6+Oct)/SiO₂-P was evaluated. It was demonstrated that the macroporous silica-based (DtBuCH18C6+Oct)/SiO₂-P materials are promising in separation of Sr(II) from high level radioactive waste.     

Preparation and properties of bio-based epoxy networks derived from isosorbide diglycidyl ether

Two bio-based epoxy prepolymers were synthesized from isosorbide, a carbohydrate-based C6 building block, using two different synthetic routes. The chemical structures of the bio-based epoxy prepolymers were analyzed by SEC, ESI-TOF MS, FTIR, ¹H NMR and ¹³C NMR analysis. The resulting epoxy prepolymers differ by the molar mass distribution, one consists of the pure epoxy monomer whereas the other exhibits various oligomeric species. A traditional petroleum-based epoxy prepolymer, DGEBA, which has similar epoxy equivalent weight, was also used in this study for comparison. Gelation and crosslinking reactions of the two bio-based epoxy precursors with an amino hardener, isophorone diamine, were studied using rheological measurements and differential scanning calorimetry (DSC) respectively; the effect of the stoichiometric ratio n_ah/n_e was investigated. Structures of the epoxy networks were evaluated using dynamic mechanical analysis (DMA) and thermo gravimetric analysis (TGA).     

Poly(ether ether sulfone)s and sulfonated poly(ether ether sulfone)s derived from functionalized 1,1‐diphenylethylene derivatives

Symmetrically disubstituted 1,1‐diphenylethylene derivatives, 1,1‐bis[4‐(t‐butyldimethylsiloxy)phenyl]ethylene and 1,1‐bis(4‐hydroxyphenyl)ethylene, were prepared by new synthesis methods and employed as functionalized monomers in the preparation of new poly(ether ether sulfone) derivatives, with the introduction of the 1,1‐diphenylethylene unit along the polymer backbone. A series of parent 1,1‐diphenylethylene based poly(ether ether sulfone)s were prepared via (a) the cesium fluoride catalysed polycondensation reactions of dihalogenated diaryl sulfones with silylated bisphenols and (b) the base catalysed aromatic nucleophilic substitution polycondensation reaction between aromatic dihalogenated diaryl sulfones with bisphenols. The post‐polymerization sulfonation reaction via the thiol‐ene addition reaction of the poly(ether ether sulfone) precursor containing the 1,1‐diphenylethylene unit along the backbone, with sodium 3‐mercapto‐1‐propane sulfonate, afforded well‐defined sulfonated poly(ether ether sulfone), with the alkyl sulfonate group introduced pendant to the polymer backbone. The organic compounds and different polymer derivatives were characterized by standard chromatography, spectroscopy, spectrometry, thermal analyses, microscopy and X‐ray diffraction measurements. © 2016 Society of Chemical Industry     

Liquid C-18 saturated acids derived from linseed oil

Liquid C-18 saturated monocarboxylic acids that fail to crystallize at −70°C. have been prepared from linseed oil, linolenic acid, and tung oil. Heating one part of linseed oil in three parts of glycol (weight-volume ratio) at 295°C. for 1 hr. with 25% excess sodium hydroxide, followed by distillation and hydrogenation of the resulting free fatty acid monomers and separation of the straight-chain components by low temperature crystallization from acetone, yielded these liquid acids. The relative proportions of cyclic acids, straight-chain monomeric acids, and polymer varied with the type of starting material and with the conditions employed. Cyclic acids in excess of 30% yields were obtained from linseed oil. Some hydroxylation of the fatty acids apparently takes place during cyclization; the amount increases with ascending temperatures, as evidenced by a rise in polyester content of the polymer fraction. Evidence indicates that the bulk of the unhydrogenated cyclic acids are vicinal disubstituted cyclohexadienes. Gas chromatography of the cyclic acids hydrogenated to an iodine value <1 shows that there are several components. These have not as yet been separated and positively identified. Presented at fall meeting, American Oil Chemists' Society, New York, N.Y., October 17–19, 1960. This is a laboratory of the Northern Utilization Research and Development Division, Agricultural Research Service, U.S. Department of Agriculture.     

Recovery of epichlorohydrin and dichloropropanols from waste

A method of recovery of the organic compounds: dichloropropanols, epichlorohydrin, 1,2,3-trichloropropane from epichlorohydrin plant waste has been performed. The method depends on the adsorption of organic compounds in the active carbon and their desorption by allyl chloride. Allyl chloride is desorbed by steam. After desorption the solutions are recirculated to the epichlorohydrin plant.     

Selective sorption of heavy metal thiocyanate complexes on crown ether resin

The sorption behavior of heavy metal thiocyanate complexes was investigated for dibenzo-18-crown-6 (DB18C6) resin and bis[2-(o-methoxyphenoxy)ethyl]ether (BMPE) resin. The DB18C6 resin showed a high sorption ability and the degree of zinc sorption increased significantly with thiocyanate concentration. This behavior was not observed for BMPE resin. The sorption behavior was influenced by the countercation species, and the degree of sorption of zinc ions showed the maximum when the potassium thiocyanate was used as a complexing salt. The sorbed species appear to be KZn(SCN)₃, K₂Zn(SCN)₄ in the potassium thiocyanate system, and Zn(SCN)₂ in the lithium thiocyanate system, respectively, according to analysis of the sorption equilibrium. Sodium and ammonium thiocyanate systems show an intermediate behavior of the two. The sorption selectivity for DB18C6 resin depended not only on the hydrophobic nature of heavy metal thiocyanate complexes but also on the stabilization of counter cation species with crown ether matrix, and the sorption selectively was found to be effectively controlled by countercation species according to the cation-chelation mechanism.