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1.
The composition of bitumen compounds from alkylated peat was determined. An increase in the yield of bitumen from alkylated peat is based on the esterification reaction. Various compounds from peat can serve as alternative raw materials for chemical industry. 相似文献
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L. Marszall 《European Journal of Lipid Science and Technology》1980,82(5):210-214
The nonionic surfactants polyoxyethylene nonyl phenol ethers have been used as models for the investigation of the change of the effective HLB of surfactants under influence of several hydroxy compounds using the phenol index method. These water-soluble additives include alcohols, glycols and glycol ethers. The change of the effective HLB of nonionic surfactant depends on the amounts and hydrophobicity of studied additives. In order to explain the change of the effective HLB of surfactants, the considerations based on the effects of the same additives on the micelle formation are also presented. These results are in remarkable agreement with the effects of the same substances on the effective HLB using other methods. 相似文献
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《国际聚合物材料杂志》2012,61(3):178-190
This work is confined to the preparation and characterization of additives. These additives are based on the reaction of polyisobutylene with different ethanolamine and then amination with tetraethylenepentamine. The molecular weights of the prepared compounds were determined by gel permeation chromatography (GPC). The efficiency of the prepared compounds as antioxidant and detergent/dispersantadditives for lube oil was studied. It was found that the efficiency increases with increasing the molecular weight and -NH- group of the prepared compounds. 相似文献
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Halogen-free flame retardant additives based on phosphorus function by developing a protective char. A variety of additives are available, ranging from the element itself, in the form of amorphous red phosphorus, to specialty organophosphorus compounds, and examples of their use in a range of thermoplastics are given. Intumescent formulations based on phosphates are especially designed for polyolefins. The behavior of a typical intumescent system is described with respect to flame retardant performance, thermal stability, water sensitivity, and filler compatibility. 相似文献
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《国际聚合物材料杂志》2012,61(10):761-771
Among the various additives employed in modern engine oils, one of the most important is the type that acts to prevent an accumulation of sludge in the crankcase and on the cylinder walls, thereby preventing sticking of piston rings and the formation of varnish-like coatings on the pistons and cylinder walls. Because of their general function of maintaining a clean engine, additives of this nature are termed detergents although it is now understood that they have little utility in cleaning a dirty engine, but by virtue of dispersing activity, prevent engine fouling. A main source of deposits is the oxidation of oil in high temperature, which can be reduced by using antioxidants. This work was limited to the preparation and characterization of different types of polyethylene glycol palmitate with different molecular weights and amination of the prepared esters with tetraethylenepentamine. The efficiency of the prepared compounds as detergents/dispersants and antioxidants was investigated and the effect of the prepared additives on other properties of lube oil was also studied. It was found that all the prepared compounds act as detergents/dispersants and antioxidant additives with no effect on the viscosity index and pour point of the lube oil. 相似文献
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The chemical composition of sedge peat from the Egor’evskoe deposit as lowland peat from Amur oblast was characterized. The elemental composition of organic matter and mineral macro- and microcomponents was studied, and the distribution of bitumens, their fractions, and humic acids in the depth of occurrence was revealed. It was found that peat genesis processes occur over the entire vertical profile, and the most converted organic matter is formed at a depth of to 90 cm. The individual composition of alkane fractions consists of C13–C36 normal structure homologues with a carbon preference index somewhat higher than unity; the presence of pristane, phytane, and farnezane was detected. In the fractions of fatty acids, predominantly even compounds from C10 to C30 were identified with special distribution features at the separate stages of peat formation. The analysis of the individual composition of n-alkanes and fatty acids made it possible to supplement botanical characteristics with information on the contribution of macrophytes, algal material, and microorganisms to the formation of the organic matter of peat. 相似文献
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Rochelle M. Cornell Rudolf Giovanoli Walter Schneider 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1989,46(2):115-134
Hydrolysis of ferric solutions leads initially to mono- and dinuclear species which interact to produce further species of higher nuclearity. These polynuclear species age eventually to either crystalline compounds or to an amorphous precipitate (amorphous iron(III) hydroxide hydrate). Amorphous iron(III) hydroxide hydrate is thermodynamically unstable and gradually transforms to α-FeO(OH) and α-Fe2O3. These crystalline products form by competing mechanisms and the proportion of each in the final product depends on the relative rates of formation. The master variable governing the rates at which these compounds form is pH. Other important factors are temperature and the presence of additives. Most additives retard the transformation and by suppressing formation of α-FeO(OH) lead to an increase in the amount of α-Fe2O3 in the product; some additives also directly promote formation of the latter compound. Metal ions can oftxen replace a proportion of Fe in the α-FeO(OH) and α-Fe2O3 lattices. At high enough concentrations they can induce formation of additional phases. Additives may also modify the morphology of the crystalline products. 相似文献
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The adsorption of cyanogen chloride on impregnated carbon containing copper and chromium compounds and other additives is accompanied by the formation of carbon dioxide. Presorbed water enhances the formation of carbon dioxide and decreases the desorption of cyanogen chloride. Cyanogen chloride is adsorbed irreversibly because hydrolysis takes place at a rate higher than that of desorption. 相似文献
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《Fuel》1987,66(6):779-784
The loss of organic material into the aqueous and gas phases in the liquefaction of raw peat with ≈ 90 wt% moisture content has been studied. The raw material was treated with CO at an initial pressure of 5.5–8.3 MPa and a temperature of 300–350 °C in the presence of K2CO3. The yield of water, water-soluble and gas products depended on the operating conditions and the chosen input material. In the liquefaction of peat with 31 wt% oxygen content the loss of material into the aqueous and gas phases decreased with increases in the initial CO pressure and the reaction temperature. The loss of organic material from peat with a high oxygen content (≈ 40 wt%) was significant. This loss of organic material is a result of thermal decomposition and hydrolysis of the organic matter of the peat and elimination of low molecular weight gases and water-soluble compounds with high oxygen and low energy contents. The selective transfer of highly oxygenated components from the peat resulted in the formation of liquid and solid residual materials with low oxygen and high energy contents. Most of the energy content of the peat becomes concentrated in the liquid and solid products (toluene- or acetone-solubles and -insolubles). The loss of organic material from the peat into the aqueous and gas phases is not accompanied by significant energy losses from the raw material. 相似文献
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G. V. Naumova A. E. Tomson N. A. Zhmakova N. L. Makarova T. F. Ovchinnikova 《Solid Fuel Chemistry》2013,47(1):22-26
The results of studies of various phenolic compounds, which are the constituents of Sphagnum magellanicum peat of different degrees of decomposition, showed that it is characterized by high concentrations of free phenol compounds, which include phenolcarboxylic acids, catechols, and flavonols. It was found that an increase in the degree of decomposition leads to a decrease in phenolcarboxylic acids in the composition of peat with a simultaneous considerable increase in the concentration of flavonols—an important group of biologically active phenol compounds. 相似文献
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The most effective smoke retarders for poly(vinyl chloride) are compounds of transition metals, such as molybdenum trioxide. MoO3 when added to a rigid PVC compound shows three general effects. First, smoke formation is reduced dramatically as measured either by the NBS smoke chamber test or Goodrich smoke–char test. Second, volatile aromatic pyrolyzate formation is also reduced dramatically. The “pure” conjugated aromatic compounds (particularly benzene and naphthalene) are reduced more than the “mixed” aliphatic–aromatic compounds (such as toluene). Third, char formation is effectively promoted. Based on results from studying MoO3 (and other metal-;based additives) in regular, perdeuterated, and syndiotactic PVC, we propose a “reductive coupling” scheme as the dominant mechanism to explain the smoke retarder action. In this mechanism the MoO3 acts in the condensed phase to promote extensive crosslinking of the PVC polymer chains very early in the thermal degradation process. Specifically, the metal additive forms a redox catalyst system which promotes intermolecular crosslinking of polymer chains to form char, rather than the conventional degradation process which gives rise to aromatics and smoke. 相似文献
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《Fuel》1986,65(2):255-259
Several different biological compounds were found to be effective pretreatment agents for the removal of water from highly humified peat by mechanical pressing. The peat was pressed for 2.5 min at 1.96 MPa. The agents added were polymers or surfactants. Two compounds were particularly effective. The cationic polysaccharide, chitosan, increased the amount of water removed by 60% compared with the control. The surfactant from Bacillus subtilis increased the amount of water removed by 〉 50%. The mechanism of dewatering by the chitosan is shown to be coagulation of the colloidal particles of peat suspended in water. This allows efficient phase separation by pressing. It is suggested that the surfactant improves dewatering by increasing the spreading coefficient between the trapped interstitial water and the peat waxes. 相似文献
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Although previous research showed that volatile compounds detected by gas chromatography (GC) correlated well with flavor
scores, no instrumental or chemical method has been available to predict flavor stability of vegetable oils reliably. A direct
GC method was tested to predict flavor stability of soybean oil by measuring induction periods based on the time required
for rapid formation of volatile compounds. By this technique, induction periods of 9, 5 and 0 days were obtained with oils
containing a combination of tertiary butylhydroquinone (TBHQ) and citric acid (CA), CA only and no additives, respectively.
Addition of methyl silicone to the oils containing CA or CA+TBHQ did not increase their stability. Prominent peaks identified
by gas chromatography-mass spectrometry included: pentane, hexanal, 2-heptanal, 2,4-heptadienal, 2-decenal and 2,4-decadienal.
Measures of total volatile compounds, pentane and 2,4-decadienal were best related to deteriorative changes. High correlation
coefficients were obtained between individual and total volatiles with flavor scores. This study showed that flavor stability
of oils can be predicted by determining induction periods based on the formation of volatile compounds. 相似文献
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Combustion of biomass with a high content of alkali (mainly potassium, K) and chlorine (Cl) can result in operational problems including deposit formation and superheater corrosion. Among the measures applied to decrease such problems are co-combustion and the use of additives. The positive effects of these measures are to a large extent either sulphation of the alkali chlorides (KCl) to less corrosive alkali sulphates or capture of alkali from KCl during release of HCl. A test campaign was carried out in a large-scale circulating fluidised boiler fired with biomass where the measures applied were sulphation by ammonium sulphate and co-combustion with peat. Their performance was evaluated by means of several advanced measurement tools including: IACM (on-line measurements of gaseous KCl); a low-pressure impactor (size distribution and chemical composition of extracted fly ash particles) and deposit measurements (chemical composition in collected deposits). The overall performance was better for ammonium sulphate, which significantly lowered KCl in the flue gas. Meanwhile no chlorine was found in the deposits. Only a minor reduction of gaseous KCl was obtained during co-combustion with peat although the chlorine content in the deposits was greatly reduced. These findings were supported by the results from the impactor measurements. 相似文献
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《Fuel》1987,66(2):232-236
Humic and fulvic acids were extracted from two peat samples designated H2 and H9 on the von Post index. The raw peat, humic acids, fulvic acids and remaining residues were tested using differential thermogravimetry in nitrogen and air. The results indicate peaks in the differential curves characteristic of each fraction. Both similarities and differences are observed; the fractions from the more decomposed H9 peat requiring higher temperatures for gasification and combustion. The results are consistent with general theories of peat formation. 相似文献
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The effect of three organophosphonic compounds on the thermooxidative degradation of the uncured diglycidyl ether-bisphenol-A epoxy resin was investigated, using infrared spectroscopy, thermogravimetry, differential thermogravimetry, static pyrolysis, pyrolysis-gas chromatography and elemental analysis. The results obtained indicate that additives with phosphorus and chlorine or nitrogen in molecules exercise an influence upon the degradative process of uncured resin by catalysing its decomposition in the lower temperature region. At the same time, the tested additives promote the formation of highly thermostable and non-flammable structures in the solid residue. 相似文献