1632-70-8Relevant academic research and scientific papers
Synthesis, characterization and isomerization performance of micro/mesoporous materials based on H-ZSM-22 zeolite
Liu, Suyao,Ren, Jie,Zhang, Huaike,Lv, Enjing,Yang, Yong,Li, Yong-Wang
, p. 11 - 23 (2016/01/20)
Micro/mesoporous materials with different mesoporosities were prepared through recrystallization of H-ZSM-22 zeolite in alkaline solution with cetyltrimethylammonium bromide template (CTAB). The structure, morphology, pore properties, acidity and isomerization performance of the catalysts by using the resulting materials were characterized and assessed. The dissolution and recrystallization procedure introduced the well-developed mesoporous structure of MCM-41 type with the meso-scale channels of about 3 nm in size on the outer surfaces of the microporous H-ZSM-22 zeolites, forming the micro/mesoporous materials, which possessed increased weak B acid sites at the pore mouths and a reduced amount of total acid sites. It is shown that the presence of well-developed mesopores could remarkably improve the selectivity to multi-branched products and suppress the side cracking reactions in n-dodecane isomerization. The micro/mesoporous Pt/ZSM-22/MCM-41 bifunctional catalyst with suitable recrystallization degree exhibits high isomerization selectivity under high conversion in long-chain n-alkane isomerization compared to the original microporous Pt/H-ZSM-22 catalyst.
Mechanism of low-molecular alkenes interaction with sulfur-containing spatially hindered phenols under conditions of thermal modification of polymer materials
Krysin,Pokrovskii,Nefedov,Shundrina,Selivanov
, p. 659 - 666 (2015/05/05)
Abstract Transformations in the course of high-temperature modification of polyolefins under action of sulfur-containing modifiers have been studied using hexene-1 and hexane as model compounds. Composition of products of thermolysis of bis[3-(3,5-di-tert
1-Hexene: A renewable C6 platform for full-performance jet and diesel fuels
Harvey, Benjamin G.,Meylemans, Heather A.
, p. 770 - 776 (2014/02/14)
A highly efficient and selective process has been developed for the conversion of 1-hexene to jet and diesel fuels. In combination with commercial processes for the dehydration of ethanol and trimerization of ethylene, this work provides a basis for the synthesis of full-performance hydrocarbon fuels from bio-ethanol. Selective oligomerization of 1-hexene with a Cp 2ZrCl2/MAO catalyst at ambient temperature and pressure resulted in 100% conversion of 1-hexene with >80% selectivity to a mixture of the dimer and trimer. The hydrogenated dimer had a -20 °C viscosity of only 3.5 mPa s, an exceptionally low freezing point of -77 °C, and a cetane number of 67 suggesting that it has performance characteristics suitable for both jet and diesel fuels. The hydrogenated trimer had a flash point of 128 °C, a cetane number of 92, a 40 °C viscosity of 3.1 mPa s, and a -20 °C viscosity of 24.5 mPa s. These properties suggest that the trimer has applications as a high-performance diesel fuel. In addition to the fuel-range hydrocarbons, heavier oligomers have potential as biolubricants which improves the carbon yield of useful products to near quantitative levels.
Formation of three-membered rings by SHi displacement. Reverse of cyclopropyl ring opening
Tanner, Dennis D.,Zhang, Liying,Hu, Li Qing,Kandanarachchi, Pramod
, p. 6818 - 6824 (2007/10/03)
The general methods, photoinitiated or peroxide-initiated free radical chain additions of halomethanes to olefins, yield 1,2-addition products at temperatures ranging from 20 to 100°C. At lower temperatures, -42 to -104°C, a competitive reaction, subsequent to the addition of CCl2X., yields alkylcyclopropanes. The reactions of 1-octene or 1-hexene and 1-methylcyclohexene with atomic hydrogen carried out in the presence of several transfer agents (CCl4, CCl3Br, CCl2Br2) initiate a radical chain addition of CCl2X. and yield cyclized materials resulting from the SHi displacement of halogen by a carbon-centered radical. The radical displacement of a halogen on carbon, the reverse of homolytic displacement on cyclopropyl carbon, is dominant at low temperatures. The rate constants for cyclization (kc) vs transfer with halomethane (kt) showed isokinetic temperatures of -46°C (CCl4, 1-hexene); -35°C (CCl4, 1-methylcyclohexene). The isokinetic temperatures for the reactions of the two substrates carried out in the presence of BrCCl3 were calculated as -204 °C (1-octene) and -109°C (1-methylcyclohexene).
RADIATION CHEMISTRY OF N-HEXANE AQUEOUS SOLUTIONS AS STUDIED BY CHROMATOGRAPHIC ANALYSIS OF FINAL PRODUCTS
Doncker, J. de,Tilquin, B.
, p. 107 - 113 (2007/10/02)
Radiolysis of dilute oxygen-free hexane aqueous solutions give dodecanes isomers analyzed by capillary gas chromatography.The relative yields for radicals which react by radical-radical recombination reactions are 39 percent, 32 percent and 29 percent for primary hexyl radical, secondary-2 hexyl radical and secondary-3 hexyl radical respectively.This distribution is changed with the N2O saturation before the radiolysis to 22 percent, 42 percent and 37 percent.If the first distribution is statistic, the increase of OH. available to attack the solute gives the distribution existing in pure alkane radiolysis.
Radiolyse des alcanes en phase liquide: nouvelles evidences experimentales et nouveau schema radiolytique
Tilquin, B.,Doncker, J. de
, p. 1195 - 1208 (2007/10/02)
Yields of final products (dimers) from the radiolysis of n-hexane and 2,3-dimethylbutane are studied by capillary chromatographic techniques for trace analysis.Reaction of intermediates with the products, the alkane molecules or impurities, is reduced by using low dose (1 kGy), low temperature (195 K) and high dose rate (LINAC).Temperature is the most important experiment variable; by reducing the temperature, reactions with sgnificant activation energies do not compete with radical-radical termination reactions.Products from LINAC radiolysis provide information about active species (reactive fragment, allylic radical...) which deserve a more detailed examination by direct methods.
Anodic Oxidation of Organoboranes
Schlegel, Guenter,Schaefer, Hans J.
, p. 1400 - 1423 (2007/10/02)
Organoboranes are converted into more easily oxidizable borates by reaction with nucleophiles and the alkyl groups are dimerized by anodic oxidation.The oxidation potentials (Ep) of the borates depend strongly on the nature of the complexing nucleophile, for instance Ep = +0.37 V (vs.SCE) with OH- or +1.65 V with tetrahydrofuran.The dimer yields are optimized with trioctylborane (5) by variation of the electrode material and the elctrolyte.At the platinum anode in sodium hydroxide-methanol/tetrahydrofuran yields of 80percent are obtained for acyclic alkyl groups, and lo wer ones for cycloalkyl groups.They exceed those obtained by the Kolbe electrolysis or the oxidation with neutral hydrogen peroxide and they are comparable to those of the AgNO3 oxidation. - The selective preparation of unsymmetrical products from borates with different alkyl groups is not possible, the dimerization proceeds likely via free radicals that couple statistically.Good yields of unsymmetrical coupling products are achieved, when one olefin is used in excess.With choro-, ethoxy-, acetoxy-, and aryl-substituted alkyl groups the dimers are obtained in 21 - 66percent yield, with bromide the yield are lower and with nitriles the dimerization fails.
