Анализ земельно-имущественного комплекса ОАО "АФ Екатеринославская" Шербакульского муниципального района Омской области

The synthesis of branched polyethylene from single ethylene feed has been achieved by using a methylaluminoxane-activated titanium complex bearing a tetradentate bis(phenolate) ligand with a 1,4-dithiabutanediyl bridge 1. This catalyst produces polyethylene with activities up to 6200 kg polymer/mol h bar. As evidenced by C-13 NMR analyses, the polyethylenes contain ethyl, n-butyl, and long-chain (n-hexyl or longer) branches in a range variable from 0.2 to 2.0%, depending on the experimental parameters. NMR and gas chromatography/mass spectrometry analyses suggest that such polymer microstructure arises from the in situ production of oligomers and their subsequent incorporation into the growing polyethylene chain. The broad molecular weight distribution of these polyethylenes indicates the presence of different catalytic species. The related catalyst system 2 bearing a longer 1,5-dithiapentanediyl bridge produces linear polyethylene with moderate activity

Investigation collision of the particles, moving in the stream of gas with the firm wall

The processes of extracting particulate matter include air, generally, the deposition of particles on dry or wetted surfaces and removing deposits from deposition surfaces. In the dust collector and the separation devices following methods of separating suspended solids from the weighing medium used: sedimentation in the gravitational field, sedimentation under the influence of inertial forces, as well as the deposition in a centrifugal field. Shock interaction of particles with the wall is a subject of research for a long time. Much of the research has been devoted to "dry" particles collision with the wall, that is a collision in a vacuum or an environment with little resistance. An important parameter characterizing the process of collision is elastic recovery ratio, defined as the ratio of the speed after impact to the velocity before impact. The calculation results show that the transfer of particles substantially in the horizontal direction depends on the particle diameter. Indeed, with an increase in particle size increases their inertia and the flow can not carry them over long distances. Furthermore, increase in size leads to an increase of deposition rate on the surface. Thus, smaller particles are transported over long distances than larger. This trend is observed for the particle size of less than 100mikron (seen in the movement of air). Next, mode of interaction with the wall varies greatly. Beat ceases to be completely inelastic. Particles incident on the wall is obtained momentum directed away from the wall and carried into the stream. Then, under the influence of gravitational forces they rise speed is slowed down, and the particles begin to move back towards the wall. The number of collisions increases with particle size. Thus, in the hammer mode of interaction the length to which the particles are transported, with their diameter increases

Синтез нанодисперсных порошков оксидов иттрия и циркония из диспергированных водно-солеорганических композиций в воздушной плазме

Polymerization of propylene promoted by the post-metallocene catalyst 1 and methylaluminoxane (MAO) produces oligomers containing prevailingly unsaturated chain ends which are diagnostic of a primary (1,2) regiochemistry of insertion. The styrene polymerization in the presence of propylene produces multiblock copolymers containing long isotactic styrene sequences interrupted by short isotactic propylene strings. The microstructure of these copolymers elucidated by 13C NMR analysis shows that the opposite regiochemistry of insertion of the two monomers is retained in the copolymerization, producing tail-to-tail and head-to-head linkages between the homopolymer blocks

10th Anniversary of Catalysts: Molecular Catalysis

On the occasion of this Special Issue, I would like to present an editorial message on this good occasion [...

Polymerization of ethylene in the presence of 1,3-dimethoxy-p-But-calix[4]arene titanium dichloride. NMR evidence of cationic titanium compound generated by methylalumoxane

In this paper we present, for the first time, the NMR investigation of the solution structure of the alkyl cationic titanium compound produced by reaction of 1,3-dimethoxy-p-Bu-1-calix[4]arene titanium dichloride and methylaluminoxane in the required conditions of ethylene polymerization. The role the methylalumoxane plays in the reaction with titanium compound is analyzed by NMR. (C) 2002 Elsevier Science B.V. All rights reserved

Ethylene polymerization promoted by dinuclear titanium p-tert-butylthiacalix[4]arene complexes

The dinuclear titanium p-tert-butylthiacalix[4]arene complexes I and 2 after activation with methylaluminoxane have been tested as homogeneous catalysts for the polymerization of ethylene. The results show that the catalytic activity of 1, although still poor, is higher than those of the related mononuclear titanium complexes bearing calix[4]arene as ligand. The molecular weight of the polyethylene produced are high (M(W) up to 1.4 x 10(6) Dalton) with broad molecular weight distribution. The polyethylenes have high melting point (133-142 degrees C) indicating a linear polymer microstructure which was confirmed by (13)C NMR analysis. (C) 2009 Elsevier Ltd. All rights reserved

Binary copolymerization of 4-methyl-1,3-pentadiene with styrene, butadiene and isoprene catalysed by a titanium [OSSO]-type catalyst

Binary copolymerization of 4-methyl-1,3-pentadiene (4MPD) with styrene, butadiene and isoprene promoted by the titanium complex dichloro(1,4-dithiabutanediyl-2,2′-bis[4,6-bis(2-phenyl-2-propyl)phenoxy])titanium activated by methylaluminoxane is reported. All the copolymers are obtained in a wide range of composition and the molecular weight distributions obtained from gel permeation chromatographic analysis of the copolymers are coherent with the materials being copolymeric in nature. The copolymer microstructure was fully elucidated by means of 1H NMR and 13C NMR spectroscopy. Differential scanning calorimetry shows an increase of glass transition temperature (Tg) with the amount of 4MPD in the copolymers with butadiene and isoprene, while in the copolymers with styrene Tg is increased on increasing the amount of styrene