EXPERIENCE IN PRODUCTION OF LARGE-SIZE TITANIUM-STEEL BIMETAL FOR PIPE BOARDS OF NPP

The main provisions of modern technology for the production of bimetallic sheets for the manufacture of pipe boards for nuclear power plant condensers and nuclear icebreaker condensers are described. High quality in connection continuity and strength is provided by explosion welding in argon medium. The results of testing the properties of 216 bimetallic steel-titanium sheets are presented.

PRECIPITATION COPOLYMERIZATION OF 4-VINYLPYRIDINE AND STYRENE

The determination of the copolymers of 4-vinylpyridine with styrene copolymers real composition, formed under the conditions of precipitation copolymerization in CCl4, is described. For this, 4-vinylpyridine with styrene was copolymerized in different ratios. The composition of the obtained copolymers was determined according to 1H NMR spectroscopy. A comparison of the real copolymers composition with the theoretically calculated ones was performed as well. The copolymerization of styrene with 4-vinylpyridine was carried out in sealed ampoules in argon medium. Solutions of a concentration of 1.02 mol/l in CCl4 were prepared. The initiator azobisisobutyronitrile in the amount of 0.00106 mol/l was added. The copolymerization was carried out in a thermostat C1823 at T = 75 ± 0.5°C. The copolymerization time was 3 hours. The original ratio of monomers (4-vinylpyridine:styrene) = 6:1; 5:1; 4:1; 3:1; 2:1; 1:2; 1:3; 1:4; 1:5; 1:6. The composition of the obtained copolymers was determined according to 1H NMR spectroscopy. It was determined that copolymers of 4-vinylpyridine with styrene obtained by precipitation copolymerization in CCl4 were enriched by 4-vinylpyridine bonds. On the contrary, the calculation of the instant composition of the copolymers according to the literature shows that under the conditions of classical copolymerization in 4-vinylpyridine solution is less active than styrene. We calculated the theoretical relative constants of copolymerization of styrene with 4-vinylpyridine: r1 = 1.97; r2 = 0.93. Therefore, under the conditions of classical copolymerization in solution 4-vinylpyridine is less active than styrene (r2 < r1). It was also found out that for the original molar content of styrene if it is greater than 0,85, it is not possible to synthesize by means of precipitation polymerization into CCl4 the copolymers of 4-vinylpyridine:styrene.

Analysis of Oil Shale Applicability for Gasification Using TGA Results

This article describes the thermogravimetric analysis (TGA) with TGA results obtained for the Russian Respublika Sakha Olenek, Kuznetsk Basin Dmitriyevka and Sergeyevka, and Chinese Jilin province Huadian oil shale deposits in air and argon medium. Industrial applicability of each shale deposit is estimated.

Effect of Argon Pressure and Aluminum Content (in TiO2-H3BO3-Al Mix) on Combustion and Formation of Chemical Composition in Combustion Products

Possibility of getting the boron-containing composite materials at aluminum-thermal combustion of boron-containing systems in argon medium. The combustion took place in reactor (at up to 30 atm. argon pressure). Influence of argon pressure and aluminum content (in initial feed) on content of the solid (titanium diboride and aluminum oxide) phases in synthesis products.