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Mihail Ionescu Zoran S. Petrović Xianmei Wan 《Journal of Polymers and the Environment》2007,15(4):237-243
Soybean polyols prepared by ring opening reactions of epoxidized soybean oil with hydrogen active compounds (water, alcohols,
organic or inorganic acids, thiols, hydrogen etc.) have a low reactivity in the reaction with isocyanates because the hydroxyl
groups are secondary. This paper presents a simple and convenient method to increase the reactivity of soybean polyols with
secondary hydroxyl groups by ethoxylation reactions with the preservation of triglyceride ester bonds. The method uses mild
reaction conditions: low alkoxylation temperature of 35–45 °C, low pressure of 0.1–0.2 MPa (15–30 p.s.i.) and a superacid
as catalyst (HBF4). The new soybean polyols have a higher reactivity toward isocyanates in polyurethane formation due to the high percentage
of primary hydroxyl groups. The primary hydroxyl content was determined by the second order kinetics of polyol reaction with
phenyl isocyanate. 相似文献
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Kalashnikov Valeriy Zaitsev Aleksandr Atroschenko Mihail Miroshnikov Sergey Frolov Alexey Zavyalov Oleg 《Environmental science and pollution research international》2019,26(24):24620-24629
Environmental Science and Pollution Research - Elemental status of 214 mares aged 3–7 years from 11 breeds was studied: Arabian purebred (n = 20), Bashkir (n = 20), Kabarda (n = 20), Vyatka... 相似文献
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Diana Rabadjieva Stefka Tepavitcharova Tihomir Todorov Manos Dassenakis Vasiliki Paraskevopoulou Mihail Petrov 《Environmental monitoring and assessment》2009,159(1-4):353-366
The inorganic chemical species in Maresh and Luda Yana rivers affected by the Cu– Mo Asarel-Medet mine, Bulgaria were determined during a low-flow and a high-flow period. The mining activities, the weathering and the oxidation processes strongly influenced the physicochemical processes in the whole water system. The main pollution source was a small lake receiving the acid effluents of the mining activities. High levels of SO4 2???, Cu, Mg, Al, Mn and Fe were determined at the mining polluted and affected stations. Cu2?+? and CuCO3 0 species (1:1) were present in the reference waters and Cu2?+? and CuSO4 0 species (1:1) in the polluted and affected waters; Cu2?+? species was dominating downstream. Me2?+? followed by $\rm{MeSO}_{4}^{\kern3pt{0}}$ (Me = Mn, Zn, Cd and Pb), $\rm{PbCO}_{3}^{\kern3pt{0}}$ and $\rm{PbHCO}_{3}^{\kern3pt{+}}$ species as well as $\rm{Fe(OH)}_{2}^{\kern3pt{+}}$ , $\rm{Al(OH)}_{4}^{\kern3pt{-}}$ , $\rm{Al(OH)}_{2}^{\kern3pt{+}}$ , $\rm{Al(OH)}_{3}^{\kern3pt{0}}$ were prevailing in the system. $\rm{MeSO}_{4}^{\kern3pt{+}}$ and $\rm{Me(SO}_{4})_{2}^{\kern3pt{-}}$ (Me = Fe, Al), $\rm{Me(SO}_{4})_{2}^{\kern3pt{2-}}$ (Me = Zn, Cd and Pb), $\rm{Me(SO}_{4})_{3}^{\kern3pt{4-}}$ (Me = Zn, Cd) and $\rm{Cd(SO}_{4})_{4}^{\kern3pt{6-}}$ species polluted and affected waters. The major elements K and Na were mainly Me?+? species, whereas Ca and Mg were Me2?+? and $\rm{MeSO}_{4}^{\kern3pt{0}}$ species in different ratios. The concentration of concentration of $\rm{NO}_{2}^{\kern3pt{-}}$ , $\rm{NO}_{3}^{\kern3pt{-}}$ and $\rm{NH}_{4}^{\kern3pt{+}}$ species as well as complex phosphorous species such as H2 $\rm{PO}_{4}^{\kern3pt{-}}$ , $\rm{FeHPO}_{4}^{\kern3pt{+}}$ , $\rm{HPO}_{4}^{\kern4pt{2-}}$ , $\rm{CaPO}_{4}^{\kern3pt{-}}$ , $\rm{CaHPO}_{4}^{\kern3pt{0}}$ and $\rm{MgHPO}_{4}^{\kern3pt{0}}$ were also calculated. The trace element concentrations decreased downstream due to dilution, sorption processes and precipitation, but the percentage of free metal species, which are more toxic, increased. An exception was iron and aluminum of which the dominant hydroxy colloidal and sulphate species were easily incorporated into the suspended phase. 相似文献
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Nicolae Scarlat Milan Martinov Jean-François Dallemand 《Waste management (New York, N.Y.)》2010,30(10):1889-1897
This paper provides a resource-based assessment of the available agricultural crop residues for bioenergy production in the European Union, at the level of the 27 Member States. The assessment provides the amount of the residues produced, collected, their present uses and the residues left available for bioenergy. This study considers the crop production and yields and multi-annual yield variation for each crop. The calculation was based on specific residues to product ratios, which were determined, depending on the crop type and crop yield. Sustainable removal rates were considered in order to protect soil fertility. The results show large spatial and temporal variations of available crop residues within EU27. The average amount of crop residues available for bioenergy in EU27 was estimated at 1530 PJ/year, with a variation between 1090 and 1900 PJ/year. The average value represents about 3.2% in final energy consumption in the EU27 while the variation 2.3–4%. This variation, which is even larger at the level of Member States, may result in shortages in biomass supply in some years, when crop residues are available in a lower amount than the average. 相似文献
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Benderev Aleksey Trayanova Mila Tarassov Mihail Tarassova Eugenia 《Environmental geochemistry and health》2022,44(7):2235-2251
Environmental Geochemistry and Health - The artesian borehole R-30–Staro Oryahovo with total depth of 1740 m gives waters of chlorine–sodium type with a mineralization of... 相似文献
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Mihail Ionescu Zoran S. Petrović Xianmei Wan 《Journal of Polymers and the Environment》2010,18(1):1-7
Soybean polyols prepared by ring opening reactions of epoxidized soybean oil with hydrogen active compounds (water, alcohols,
organic or inorganic acids, thiols, hydrogen etc.) have a low reactivity in the reaction with isocyanates because the hydroxyl
groups are secondary. This paper presents a simple and convenient method to increase the reactivity of soybean polyols with
secondary hydroxyl groups by ethoxylation reactions with the preservation of triglyceride ester bonds. The method uses mild
reaction conditions: low alkoxylation temperature of 35–45 °C, low pressure of 0.1–0.2 MPa (15–30 p.s.i.) and a superacid
as catalyst (HBF4). The new soybean polyols have a higher reactivity toward isocyanates in polyurethane formation due to the high percentage
of primary hydroxyl groups. The primary hydroxyl content was determined by the second order kinetics of polyol reaction with
phenyl isocyanate. 相似文献