共查询到20条相似文献,搜索用时 31 毫秒
1.
Majid Montazer Fatemeh Dadashian Nahid Hemmatinejad Kajal Farhoudi 《Applied biochemistry and biotechnology》2009,158(3):685-693
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. 相似文献
2.
Andreadou I Tsantili-Kakoulidou A Spyropoulou E Siatra T 《Chemical & pharmaceutical bulletin》2003,51(10):1128-1131
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. 相似文献
3.
Kuo-Chung Cheng 《Journal of Polymer Science.Polymer Physics》1998,36(13):2339-2348
The systems of diepoxides cured with primary amine in presence of an monoepoxide, monofunctional reactive, under equal stoichiometric ratio has been analyzed by a generating function method. The average degree of polymerization, which changed with time or conversion, and gel point were calculated. The profiles of the degree of polymerization and critical conversion are dependent on the content of and relative reactivities of epoxy groups. For a system with the same ratio, the critical epoxy conversion increases with increasing reactivity. © 1998 John Wiley & Sons, Inc. J. Polym. Sci. B Polym. Phys. 36: 2339–2348, 1998 相似文献
4.
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)2CCFCF2CF3. Many new ketenimines, eneamines, amidines, nitriles, and quinoline derivatives are reported. 相似文献
5.
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. 相似文献
6.
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. 相似文献
7.
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. 相似文献
8.
Jana Hrachová Peter Komadel Ivica Janigová Miroslav Šlouf Ivan Chodák 《先进技术聚合物》2012,23(10):1414-1421
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. 相似文献
9.
应用壳聚糖将葡萄糖氧化酶固定于鸡蛋膜上,结合氧电极制得葡萄糖传感器.实验表明,壳聚糖比戊二醛能更好地固定葡萄糖氧化酶,最佳条件为壳聚糖浓度0.3%、固定化酶量0.8 mg、 pH 7.0、缓冲溶液浓度300 mmol/L和温度25 ℃.本葡萄糖传感器的线性范围为0.016~1.10 mmol/L;检出限为8.0 μmol/L(S/N=3), 响应时间<60 s,有很好的稳定性,寿命>3个月.同一个传感器重复使用以及同方法制作的不同传感器之间都有很好的重现性,RSD分别为2.5%(n=10)和4.7%(n=4).实际样品中可能存在的烟酰胺、 VB6、 VB12、 VE、Ca2+、 Mg2+、 K+和Zn2+等对葡萄糖的测定不产生干扰.本传感器已成功地应用于市售饮料中葡萄糖含量的测定. 相似文献
10.
Sedimentation of carbon-clay dispersions with polyacrylamide modified with tetraethylene glycol was studied. The concept of the formation of a binary structure of the modified polymer in a structured ternary system was formulated. 相似文献
11.
Excess thermodynamic functions (free energies, enthalpies and entropies of mixing) have been obtained from measurements of vapour pressures, together with excess volumes of mixing, for mixtures of hexafluorobenzene with carbon tetrachloride and with perfluoromethyl-cyclohexane (tetradecafluoromethylcyclohexane). Deviations from thermodynamic ideality are large, although the systems are completely miscible. Critical temperatures of the mixtures are also reported. A correlation between the data, anticipated from a simple model for mixtures of asymmetric molecules, does not obtain. 相似文献
12.
Giovanni Moggi Piergiorgio Bonardelli Claudio Monti Jan C. J. Bart 《Journal of Polymer Science.Polymer Physics》1985,23(6):1099-1108
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. 相似文献
13.
V. B. Kalcheva L. S. Peshakova D. A. Simov 《Chemistry of Heterocyclic Compounds》1984,20(11):1210-1213
The reaction of 2-aminobenzoxazoles with activated alkenes of the acrylic acid type and its derivatives and methyl vinyl ketone proceeds in the presence of basic catalysts to give products of mono- and diaddition at the exocyclic nitrogen atom. The reaction of 5(6)-substituted 2-aminobenzoxazoles with esters of propyl and acetylenedicarboxylic acids in the absence of catalysts leads to the production of condensed 2-oxopyrimidines. The effect of substituents and the reaction conditions on the course of the process was investigated.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1467–1471, November, 1984. 相似文献
14.
The composition and stability of mixed complexes of cadmium or lead with hydroxide and monoethanolamine have been determined polarographically at 25° in aqueous and aqueous methanol solutions at ionic strength 0.1M. For the aqueous solutions the results agree with those of others. In the methanolic systems the previously unreported complexes Cd(MEA)4(OH), Pb(MEA)(OH)3, Pb(MEA)2(OH) and Pb(MEA)2(OH)2 were detected. 相似文献
15.
Lithium salts of allylic sulfones are oxidized with ferric chloride-dimethyl-formamide complex mainly to 1,6-disulfones by 3-3′ coupling. Products resulting from coupling of 3,3-disubstituted sulfones undergo Cope rearrangement affording vicinal disulfones with threo-configuration. Coupling with iodine results in mixtures containing mainly vicinal disulfones, again with threo-configuration. 相似文献
16.
María S. Shmidt Isabel A. Perillo Mercedes González María M. Blanco 《Tetrahedron letters》2012,53(20):2514-2517
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. 相似文献
17.
Gabriel Bernardo Nabankur Deb Stephen M. King David G. Bucknall 《Journal of Polymer Science.Polymer Physics》2016,54(10):994-1001
The phase behavior of [6,6]‐phenyl C61‐butyric acid methyl ester (PCBM) blends with amorphous polymers with different degrees of aromaticity has been investigated by differential scanning calorimetry (DSC) and small‐angle neutron scattering (SANS). The polymers investigated are the homologous series of polystyrene (PS), poly(2‐vinyl‐naphthalene) (P2VN), and poly(9‐vinyl‐phenanthrene) (P9VPh). The DSC results show that the miscibility of PCBM in these polymers increases nonlinearly from 16.5 wt % in PS, 57.0 wt % in P2VN, and 74.9 wt % in P9VPh. The SANS results show that at all concentrations of PCBM, the blends are composed of two mixed phases. Analysis shows that the phase dimensions remain largely independent of PCBM content, but there is a strong dependence of the PCBM concentration difference in the two phases with increasing PCBM content. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016 , 54, 994–1001 相似文献
18.
M. García-Padial M. C. Martínez-Ohárriz J. R. Isasi I. Vélaz A. Zornoza 《Journal of inclusion phenomena and macrocyclic chemistry》2013,75(3-4):241-246
Tyrosol (TY), 4-(2-hydroxyethyl)phenol, is an olive oil biophenol with antioxidant activity and positive effects on human health. This study has investigated the interactions of TY with cyclodextrins (CD) and a CD polymer. Complexation of TY with β-CD, hydroxypropyl-β-CD (HP-β-CD), and methyl-β-CD (Me-β-CD) has been evaluated both in aqueous solution and in the solid state. The techniques employed in solution to determine the apparent stability constants of the respective complexes were fluorescence and UV–visible spectroscopies. Complexation with β-CD and its derivatives involved an increase of both the UV absorbance and the intrinsic fluorescence of TY; a bathochromic shift of the UV spectrum was detected as well. The apparent stability constants obtained with native β-CD, Me-β-CD and HP-β-CD presented similar values. Complexes in the solid state were obtained by coevaporation and kneading. They were characterised by X-ray diffraction analysis and differential thermal analysis. The interaction of TY with β-CD led to a crystalline complex; the same diffraction pattern was obtained by coevaporation and kneading. The complexes obtained with methyl- and HP-β-CD were amorphous irrespective of the preparation method. In addition, the retention of TY in an insoluble polymer of CD crosslinked with epichlorohydrin has been quantified. In approximately 20 min, 1 mg of TY per gram of polymer was retained. 相似文献
19.
Effects of various factors on the extraction of zinc with carboxylic acids and their mixtures with amines into a micellar phase of a nonionic surfactant at the cloud point were studied. The conditions for the atomic-absorption determination of zinc preconcentrated into an OP-10 phase on heating with capric acid and n-octylamine were developed. 相似文献
20.
Anthony Stuart Brown Kiyohisa Fujimori Ian E. Craven 《Journal of polymer science. Part A, Polymer chemistry》1989,27(10):3315-3325
A nonaqueous potentiometric direct titration method was used to determine the composition diagrams for the copolymerization of maleic anhydride with styrene and with vinyl acetate in methyl ethyl ketone at 50°C. The data were analyzed using nonlinear least-squares minimization routines to fit composition equations for the terminal, penultimate, and complex models directly. The applicability of each model to both systems were evaluated statistically. The penultimate model was found to best describe both systems, although in the case of the maleic anhydride/vinyl acetate system this was only a small improvement over the terminal model. Although significant comonomer complexation occurs in both systems, the complex model did not provide statistically significant improvement in fit to the data compared with the terminal model. 相似文献