Copolymers of tetrafluoroethene with chlorotrifluoroethene and with bromotrifluoroethene

Tetrafluoroethene (TFE)–chlorotrifluoroethene (CTFE) and TFE–bromotrifluoroethene (BTFE) copolymers have been synthesized by solution copolymerization over the entire range of comonomer composition. Crystallinity data are reported and first- and second-order transitions have been investigated by DSC. Glass transition temperatures of TFE-CTFE copolymers vary in a nonlinear fashion in the range defined by the homopolymers conforming best to the Johnston equation; the behavior in the TFE-BTFE system is more linear. Whereas TFE-BTFE copolymers show a steep decrease of melting temperature at higher BTFE content, due to the amorphous character of the polymers, more regular behavior was found for TFE-CTFE copolymers. Enthalpies of fusion are also reported. The results are discussed in relation to copolymer composition and structure and are compared with data on tetrafluoroethene–hexafluoropropene (FEP) fluorocarbon resins.     

Enthalphy of mixing of bromobenzene with n-alkanes,with cyclohexane,and with benzene

A dynamic flow microcalorimeter of the Picker design was used to measure enthalpies of mixing at 298.15 K and atmospheric pressure of the six binary systems bromobenzene + n-hexane, + n-heptane, + n-nonane, + n-tetradecane, + cyclohexane, and + benzene. Within the homologous series of n-alkane systems, the interaction parameter, h₁₂, calculated from rigid-lattice group contribution theory, decreases weakly with increasing chain length of the alkane. This behavior is quite analogous to that observed with chloro-derivatives of benzene + n-alkane.     

Reactions of amines with a dimer of hexafluoropropene and with a perfluorovinyl sulfide prepared with hexafluoropropene

Some reactions of amines with a perfluorovinylsulfide, (CF₃)₂CFSC(CF₃)CFCF(CF₃)₂, prepared from hexafluoropropene (HFP) and sulfur [1] are compared to reactions of the same amines with the thermodynamic dimer of HFP, (CF₃)₂CCFCF₂CF₃. Many new ketenimines, eneamines, amidines, nitriles, and quinoline derivatives are reported.     

Reaction of isatin with alkylating agents with acidic methylenes

The reaction of isatin (1) with different alkyl halides 2 and alkaline carbonates in aprotic polar solvents leads mainly to N-alkyl derivatives 3. The use of alkylating agents that have acidic methylenes leads to competitive formation of the corresponding epoxide 5. The formation of 5 is favored by low-polarity solvents at low temperatures and strong bases. Epoxides 5c, d obtained using NaEtOH/EtOH at 0–5 °C are transformed into the corresponding 4-quinolinones 6 at higher temperatures. The use of Ag₂CO₃ allows obtaining compounds 3 as major products, along with varying amounts of labile O-alkyl derivatives 4 and dimerization products.     

High-temperature reactions of trichloroethylene with toluene and with methanol

Conclusions The reactions of trichloroethylene with toluene and with methanol, conducted 560–570°, leads to the formation of a mixture of the isomers R-CH=CCl₂ and cis- and trans-R-CCl=CHCl (R=CH₂C₆H₅ and CH₂OH).Translated from Izvestiya Akademii Nauk SSSR. Seriya Khimicheskaya, No. 12, pp. 2777–2778, December, 1967.We thank E. D. Lubuzh and A. V. Kessenikh for determining and interpreting the IR and NMR spectra.     

Treatment of Wool with Laccase and Dyeing with Madder

This research has explored the effect of laccase (Denilite ІІ S) on the physical properties of the wool fabric and confirms the anti-felting of wool. In the experiment, laccase was applied to a wool fabric and different characteristics including weight loss, strength, alkali solubility, felting shrinkage, water drop absorption, and dye ability with madder were studied. The surface morphology of the wool fabrics was also observed by scanning electron microscope. The results indicated that the wool fabric treated with laccase has a higher water drop absorption, lower felting shrinkage, and lower values of a ^* and b ^*. Treatment of a wool fabric with 10% or lower percentage of laccase reduced the fabric weight but increased the tensile strength. However, using higher concentration of laccase reduced fabric weight and tensile strength. The dyeing of laccase pre-treated wool fabric with madder indicated a lower lightness.     

Reactions of indole derivatives with cardioprotective activity with reactive oxygen species. Comparison with melatonin

We have previously reported on the synthesis of novel indole derivatives containing an amine-triazole moiety (1a-d, 2a-c), and their antioxidant activity on in vitro non-enzymatic rat hepatic microsomal lipid peroxidation. Some of the compounds showed protective activity against oxidative injury of ischemic myocardium. In the present paper we investigated the interactions of these derivatives with reactive oxygen species, in order to find a mechanism of their antioxidant capacity and to identify structural characteristics responsible for these properties. These interactions were compared with melatonin, which is also an indole derivative. The antioxidant profiles of the compounds were established by different in vitro protocols as follows: 1) by the interaction of the compounds with the 1,1-diphenyl-2-picrylhydrazyl (DPPH) stable free radical, 2) their scavenging effects on superoxide anions using an enzymic system of xanthine-xanthine oxidase, 3) their inhibitory effects on xanthine oxidase and 4) their ability to scavenge hydroxyl radicals by comparison with dimethyl sulfoxide (DMSO) for *OH. All compounds were found to interact with DPPH, most of them to be superoxide anion scavengers and to be strong hydroxyl radical scavengers. Derivatives 1a and 1d substituted on the nitrogen of the indolic nucleus were found to have better antioxidant properties than the reference compounds used and melatonin.     

Determination of Ni with Electrodes Modified with Mordant Violet 5

Abstract

The utility of electrodes modified with the dye Mordant Violet 5 (MV-5) for the determination of Ni is demonstrated. The method is based on the coordination of Ni from solution by an immobilized layer (via ion exchange) of the dye. Upon coordination the redox response of the dye is shifted in the negative direction by about 250 mV (from ?0.74 to ?0.97 V). The height of this peak is used as the analytical signal which is related to the concentration of Ni in solution. Linear calibration curves were obtained for Ni concentrations ranging from about 10^?4 to 2×10^?3M. Although this reflects only moderate sensitivity, a basic concept is established; this method allows for the determination of the metal via the redox response of the dye. Thus, with appropriate choice of reagents, metal ions difficult to determine by direct reduction can be determined by this method. The use of other reagents may result in enhanced sensitivity.     

Reactions of p-Nitrophenyloxirane with Amines Containing Fragments with Bicyclic Skeleton

Reactions of p-nitrophenyloxirane with amines containing fragments with bicyclic skeleton of norbornene, norbornane, epoxynorbornane (stereoisomeric exo- and endo-5-aminomethylbicyclo[2.2.1]hept-2-enes, N-benzyl-endo-5-aminomethylbicyclo[2.2.1]hept-2-ene, endo-5-(2-aminoethyl)bicyclo[2.2.1]hept-2-ene, stereoisomeric exo- and endo-2-aminomethylbicyclo[2.2.1]heptanes, 2-(1-aminoethyl)bicyclo[2.2.1]heptane, exo-5-aminomethyl-exo-2,3-epoxybicyclo[2.2.1]heptane) were investigated. The aminolysis of p-nitrophenyloxirane occurred regioselectively according to Krasusky rule as was proved by ¹H and ¹³C NMR data. As shown by ¹H and ¹³C NMR spectroscopy the oxyalkylation product obtained from N-benzyl-endo-5-aminomethylbicyclo[2.2.1]hept-2-ene was composed of two diastereomers originating from the presence of a chiral nitrogen atom in the rear part of the rigid bicyclic skeleton. New products of amino groups transformation in the molecules of hydroxyamines were obtained by reaction with p-methylbenzoyl chloride and p-nitrophenylsulfonyl chloride. Regioselectivity of the attack of electrophilic reagents on the nitrogen in the hydroxyamines was confirmed by IR and ¹H NMR spectra of the products. The data on pharmacological activity tests of N-2-hydroxyethyl(p-nitrophenyl)-5-aminomethylbicyclo[2.2.1]hept-2-ene are reported.     

Copolymerizations of 2-hydroxyethylmethacrylate with vinylpyridines and with N-substituted methacrylamides

Studies were made of the copolymerizations of 2-hydroxyethylmethacrylate with 2-, 3- and 4-vinylpyridine. N-(trans-4′-nitro-4-stilbenyl)methacrylamide and N-(trans-4-stilbenyl)methacrylamide. Methods of Fineman-Ross, Joshi-Joshi, Tidwell-Mortimer and Tosi were employed to determine monomer reactivity ratios; the results for 2- and 4-vinylpyridine were compared with those calculated from the Q-e scheme. The monomer reactivity ratios for 2-hydroxyethylmethacrylate with vinylpyridines calculated by different methods showed good agreement. The monomer reactivity is briefly discussed.     

Properties of rubber filled with montmorillonite with various surface modifications

Layered silicate/natural rubber composites were prepared by direct polymer melt intercalation. Na‐montmorillonite Kunipia‐F and its organic derivates (organo‐clays) prepared by ion exchange were used as clay fillers. Silica (SiO₂) Ultrasil VN3, a filler commonly used in the rubber industry, was used in combination with clay fillers. The effect of clay or organo‐clay loading from 1 up to 10 phr without (0 phr) or with silica (15 phr) showed significant improvement of the tensile properties (stress at break, strain at break and modulus M100). Modification of montmorillonite by three alkylammonium cations with the same length of alkylammonium chain (18 carbons) and different structure resulted in altered reinforcing and plasticizing effects of the filler in composites with rubber matrix. Copyright © 2011 John Wiley & Sons, Ltd.     

具有氮杂环并叶绿素色基结构的二氢卟吩衍生物的合成

采用一锅法从叶绿素-a制得132-氧代焦脱镁叶绿酸-a甲酯,再与邻苯二胺反应生成四种含氮杂环并二氢卟吩衍生物,再经硝酸铊或者四氧化锇氧化将其3-位乙烯基转化成高反应性的甲酰基和甲酰甲基.C3-甲酰甲基与邻氨基苯甲醛的Friedl nder缩合顺利地环合成喹啉结构,与重氮甲烷和氧化苯甲腈的1,3-偶极环加成反应在3-位上构建了五元杂环.首次报道的具有叶绿素基本碳架的二氢卟吩衍生物的化学结构均经UV,IR,1H NMR及元素分析得以证实.