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61.
Multiblock poly(ester-block-amide)s (PEA) elastomers comprising hard blocks of oligoamide and oligoester soft segments were prepared and their structure-property relations were analysed. The polycondensation reaction of oligoesters (prepared from 1,4-butanediol and dimerized fatty acid) with oligolaurolactam (PA12) gave copolymer series with variable blocks content (the soft segments content was varied from 24 to 60 wt.%). PEAs are the phase system composed of crystallised sequences of oligoamide (hard segment phase) as well as oligoesters (soft segment phase). Mixing between the hard and soft phases was studied by thermal and mechanical measurements (DSC, DMTA). These results have indicated on a multiphase structure of investigated materials. The relationship between the observed thermal and tensile properties and the soft/hard segments content indicated on an increase of the phase separation with soft segments content. 相似文献
62.
Jeong SD Nowak-Król A Kim Y Kim SJ Gryko DT Lee CH 《Chemical communications (Cambridge, England)》2010,46(46):8737-8739
meso-Alkylidene (m-benzi)pentaphyrin containing exocyclic C=C double bonds at two meso-positions is synthesized and fully characterized for the first time. The single crystal X-ray crystallographic analysis shows a concave conformation with two pyrrole rings inverted. The first protonation occurs exclusively at core nitrogen. The synthesized compound displays concentration dependent chromogenic responses for fluoride anion in organic solvent. 相似文献
63.
Paweł Mierczynski Piotr Kaczorowski Agnieszka Ura Waldemar Maniukiewicz Marcin Zaborowski Radoslaw Ciesielski Adam Kedziora Tomasz P. Maniecki 《Central European Journal of Chemistry》2014,12(2):206-212
Ternary CuO-ZrO2-Al2O3 catalysts promoted by palladium or gold were prepared and tested in CO hydrogenation reaction at 260°C under elevated pressure (4.8 MPa). The promotion effect of palladium or gold addition on the physicochemical and catalytical properties of CuO-ZrO2-Al2O3 catalysts in methanol synthesis (MS) was studied. The catalysts were characterized by BET, XRD, TPR-H2, TPD-NH3 methods. The BET results showed that the ternary system CuO-ZrO2-Al2O3 had the largest specific surface area, cumulative pore volume and average pore size in comparison with the promoted catalysts. The yield of methanol can be given through the following sequence: 5%Pd/CuO-ZrO2-Al2O3 > CuO-ZrO2-Al2O3 > 2%Au/CuO-ZrO2-Al2O3. We also found that the presence of gold or palladium on catalyst surface has strong influence on the reaction selectivity. The high selectivity of gold doped ternary catalyst is explained by the gold-oxide interface sites created on the catalyst surface and the acidity of those systems. The higher selectivity to methanol in the case of the palladium catalyst is explained by the spillover effect between Pd and CuO. 相似文献
64.
Agnieszka Zgoła-Grześkowiak 《Journal of chromatography. A》2010,1217(11):1761-1766
Dispersive liquid–liquid microextraction (DLLME) coupled with high-performance liquid chromatography with fluorescence detector was applied for the determination of alkylphenols and their short-chained ethoxylates in water samples. Development of DLLME procedure included optimisation of some important parameters such as kind and volume of extracting and dispersing solvents. Under optimised conditions 50 μL of trichloroethylene in 1.5 mL of acetone were rapidly injected into 5 mL of a water sample. After centrifuging the organic phase containing the analytes was taken for evaporation with a gentle nitrogen purge and reconstituted to 50 μL of acetonitrile. The aliquot of this solution was analysed with the use of HPLC. For octylphenol (OP) and octylphenol ethoxylates (OPEOs) linearity was satisfactory in the range 8–1000 μg L−1 and for nonylphenol (NP) and nonylphenol ethoxylates (NPEOs) linearity was in the range from 50 to about 3000 μg L−1. Limit of quantitation was 0.1 μg L−1 for OP and OPEOs and 0.3 μg L−1 for NP and NPEOs. Satisfactory recoveries between 66 and 79% were obtained for environmental samples. The results showed that DLLME is a simple, rapid and sensitive analytical method for the preconcentration of trace amounts of alkylphenols and their ethoxylates in environmental water samples. 相似文献
65.
Agnieszka Wróblewska Egbert Meissner Eugeniusz Milchert 《Journal of fluorine chemistry》2006,127(3):345-350
The influence of technological parameters on the dehydroiodination of perfluoroalkylethene iodides (CF3)2CF(CF2CF2)nCH2CH2I, where n = 1, 2, 3 and 4, has been investigated. The most advantageous conditions for the two-stage oxidation of (CF3)2CF(CF2CF2)nCHCH2, with ozone in the first stage, followed by the oxidation with hydrogen peroxide to the perfluorocarboxylic acids, were determined. The effects of temperature and time on the conversion of perfluoroalkylethenes during the oxidation with ozone were studied. In the second stage, the selectivity of transformation (of each homologue) to the perfluorocarboxylic acid in relation to the theoretical amount resulting from a quantity of perfluoroalkylethene used and the conversion of perfluoroalkylethene in the temperature range of 10-80 °C has been determined. 相似文献
66.
Investigation of the oxidation reaction of electron rich alkoxy substituted β-aryl β-hydroxyphosphonates to corresponding β-ketophosphonates, which may be utilized in syntheses of lignans with various oxidizing agents (PCC, PDC, SIBX, CAN, Oxone®, KMNO4/SiO2, KMnO4/MS 4 Å, KMnO4/CuSO4, KMnO4/CuSO4/Al2O3, MnO2, CrO3/SiO2, H2O2/salen) is described. The effect of oxidants and reaction conditions on the reaction efficiency and yield was also investigated. 相似文献
67.
Agnieszka Ulanowska Ewa Trawińska Piotr Sawrycki Bogusław Buszewski 《Journal of separation science》2012,35(21):2908-2913
Chemotherapy used as a treatment against lung cancer has influence on metabolic processes occurring in healthy cells. The changes of biochemical pathways proceeded inside cells might be observed in expired air. In the experiment, breath analysis was carried out before and after anticancer therapy. Expired air samples were collected from 22 patients with a biopsy confirmed lung cancer. Volatile organic compounds present in breath were analyzed by gas chromatography/mass spectrometry. For enrichment of analytes solid‐phase microextraction technique was applied. Eight fibers covered by different sorbents were tested. Carboxen‐polydimethylsiloxane fiber revealed the highest extraction efficiency in relation to analytes in breath. The data showed that cytostatic drugs increase the concentration of acetone and isoprene in the breath collected after chemotherapy. Volatile metabolites of administrated drugs were not identified in expired air. 相似文献
68.
Bogdan Boduszek Agnieszka Halama 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1)
Abstract As part of our studies mto the synthesis of benzylic aminophosphonates we have found, that hydroxybenzyl(amino)osphonates underwent a cleavage in strong basic conditions to form aldehydes, amines and phosphorous acid, in high yield. 相似文献
69.
70.
Dobosz B Drzewiecka K Waskiewicz A Irzykowska L Bocianowski J Karolewski Z Kostecki M Kruczynski Z Krzyminiewski R Weber Z Golinski P 《Applied magnetic resonance》2011,41(1):19-30
Electron paramagnetic resonance was used to monitor free radicals and paramagnetic species like Fe, Mn, Cu generation, stability and status in Asparagus officinalis infected by common pathogens Fusarium proliferatum and F. oxysporum. Occurrence of F. proliferatum and F. oxysporum, level of free radicals and other paramagnetic species, as well as salicylic acid and mycotoxins content in roots and stems of seedlings were estimated on the second and fourth week after inoculation. In the first term free and total salicylic acid contents were related to free radicals level in stem (P?=?0.010 and P?=?0.033, respectively). Concentration of Fe(3+) ions in porphyrin complexes (g?=?2.3, g?=?2.9) was related to the species of pathogen. There was no significant difference between Mn(2+) concentrations in stem samples; however, the level of free radicals in samples inoculated with F. proliferatum was significantly higher when compared to F. oxysporum. 相似文献