Presence Of Complex Catalysts Research Articles

Activation energy and thermal effect of initiation reaction cationic polymerization of p-methylstyrene in the presence of complex catalysts: boron fluoride - hydrogen fluoride and boron fluoride - water in toluene

Activation energy and thermal effect of initiation reaction cationic polymerization of p-methylstyrene in the presence of complex catalysts: boron fluoride - hydrogen fluoride and boron fluoride - water in toluene

Effect of the VIII group metals on the catalytic pyrolysis of lower alkanes

Catalytic pyrolysis of lower hydrocarbons C1–C4 was studied in a continuous flow tubular reactor in the presence of complex catalysts containing the VIII group metals: Fe, Co, Ni, Pd, applied as salts on the reactor walls or on a ceramic support. The catalytic activity of the metal-containing compositions is compared, the effect of the metal nature on the yield of ethylene and propylene is studied and soot formation is estimated. The kinetic and activation parameters for decomposition of the hydrocarbon mixture and accumulation of the products are calculated. In the empty reactor, the best results were observed for the catalyst on the basis of Co-phosphate coating, while for reactors packed with coated ceramic support it was the Fe-containing catalyst.

X-Ray Analysis of Methyl Cis-1-chloro-2-trichloromethylcyclopentane-1-carboxylate

Recently we have found that the products of 4,3-addition of trichloroacetic acid derivatives to 1,1-dichloro-4-methyl1,3-pentadiene in the presence of complex catalysts based on univalent copper undergo intramolecular cyclization, forming cyclobutanes with functional substituents [1, 2]. It was assumed that the stereoisomer composition of the isolated cyclobutanes depends on the ability of the functional group of the starting acid to be coordinated to the transition metal ion [3]. Further evidence in support of the observed tendencies was provided by cyclization of methyl 2,2,7,7-tetrachloro6-heptenate (prepared from methyl dichloroacetate and 1,1-dichloro-5-bromo-1-pentene by the procedure of [4], yield 72%) to 1-chloro-trichloromethylcyclopentane-1-carboxylic acid ester in the presence of amine complexes of univalent copper.

96/06392 Pyrolysis of low-rank coals in presence of complex catalyst: ESR study

96/06392 Pyrolysis of low-rank coals in presence of complex catalyst: ESR study

Oligomerization of piperylene and piperylene fraction in the presence of complex catalysts based on aluminium chloride

Oligomerization of piperylene and piperylene fraction in the presence of complex catalysts based on aluminium chloride

Disproportionation of 2-pentene in the presence of complex catalysts on polymeric supports

1. By polymerizing various monomers in the presence of transition-metal salts (e.g., WCl6) and a Grignard reagent, disproportionation catalysts containing a carbochain polymeric support have been obtained. Lewis acids were used as cocatalysts for the disproportionation of the olefins. 2. The activity and selectivity in the action of the catalytic systems obtained have been studied as a function of the nature of the cocatalyst, the ratio of the components, and the nature of the solvent in the disproportionation of 2-pentene.

Reduction of olefins by formic acid catalyzed by transition metal complexes

1. Formic acid in the presence of complex catalysts can reduce olefins and acetylenes. 2. The addition of alkali metal formates makes it possible to carry out the reduction under milder conditions than in the case of pure formic acid.

Polymerization of allyl chloride and some of the properties of the polymer

The polymerization of halogen-containing monomers, such as vinyl chloride, chloroprene [1–3], 2,3-dichloro-1,3-butadiene [4] and others in the presence of complex catalysts has a slow rate and large utilization of the catalyst (about 4% by weight of the monomer). Vinyl chloride [5] and compounds containing a reactive halogen atom, such as allyl chloride [6], allyl bromide [7], crotyl chloride [6], and other monomers of similar structure, are used to reduce the molecular weight (mol. wt.) of the polyolefins produced in the presence of titanium containing catalytic systems. For this reason, and also in order to clarify the causes of complex catalyst inactivation by the monomer with a reactive halogen atom, and the mechanism of their homopolymerization, we examined the polymerization of allyl chloride in the presence of vanadium-containing complex catalysts of cationic type. The study of the properties of pollyallyl chloride (PAC) (a close homologue of polyvinyl chloride), which is a model for the still unknown polypropylene chlorinated at the CH 3 group was also of special interest.

Polymerization of α-amylenes in the presence of complex catalysts

Polymerization of α-amylenes in the presence of complex catalysts

Polymerization of α-amylenes in the presence of complex catalysts : M. P. Berdnikova, Yu. V. Kissin and N. M. Chirkov, Vysokomol. soyed. 5: No. 1, 63–67, 1963

Polymerization of α-amylenes in the presence of complex catalysts : M. P. Berdnikova, Yu. V. Kissin and N. M. Chirkov, Vysokomol. soyed. 5: No. 1, 63–67, 1963

The polumerization of ethylene by the complex catalyst α-TiCl 3—air 3 in the presence of various monomers—II. Some aspects of the mechanism of polymerization in the presence of complex catalysts

The polumerization of ethylene by the complex catalyst α-TiCl 3—air 3 in the presence of various monomers—II. Some aspects of the mechanism of polymerization in the presence of complex catalysts

Kinetics and mechanism of the polymerization of α-olefins in the presence of complex catalysts : I. N. Meshkova, S. A. Kumankova, V. I. Tsvetkova and N. M. Chirkov, Vysokomol. soedin. 3: No. 12, 1816–1822, 1961

Kinetics and mechanism of the polymerization of α-olefins in the presence of complex catalysts : I. N. Meshkova, S. A. Kumankova, V. I. Tsvetkova and N. M. Chirkov, Vysokomol. soedin. 3: No. 12, 1816–1822, 1961

The kinetics and mechanism of the polymerization of α-olefins in the presence of complex catalysts

As was shown in previous work [1] during the polymerization of ethylene in the presence of titanium tetrachloride and tri-ethyl-aluminium, a sharp fall in the rate of polymerization with time is observed and is connected with a conversion which is taking place in the catalyst itself. The components of the catalyst react so readily with each other, that even a considerable reduction of the temperature (from 70 to 56°) does not succeed in slowing down the process of conversion of the catalyst to the less active form, and in stabilizing the catalytic system at a high level of activity. Because of the rapid interaction of TiCl 4 and Al(C 2H 5) 3 it is experimentally difficult to establish how the utilization and dissociation of the most active catalytic complex takes place and what the activity of the system is at the zero moment of time, when the composition of the catalyst must consist only of TiCl 4 and Al(C 2H 5) 3. As a result of the supposition, that the decrease of the catalytic activity of the system with time, is, in the first place, connected with a strong reduction of titanium we chose, for the subsequent investigations, di-iso-butyl-aluminium chloride, the reducing properties of which are less than those of tri-ethyl-aluminium [2]. A study of the kinetics of the polymerization of ethylene in the presence of TiCl 4+Al( iso-C 4H 9) 2Cl was carried out ethylene pressures from 50 to 250 mm, with ratios of Al( iso-C 4H 9) 2Cl: TiCl 4 from 0.69: 1 to 3.3:1, at intervals of temperature from 30 to 70°, in a medium of heptane.