European Reviews of Chemical Research

4-9

Authors: Marat I. Abdullin, Azamat A. Basyrov, Sergey N. Nikolaev, Yuliya A. Koksharova, Nikolay V. Koltaev

The article shows the possibility of printing materials using the 0809M ABS plastic. There have been determined the optimum temperature and feed rate of ABS filaments for obtaining prototypes of the highest quality. We have studied the physico-mechanical characteristics of the prototype, depending on the method of application of the polymeric material.

22-26

Authors: Lili Janiashvili, Giuli Andronikashvili, Archil Varadashvili, Mzia Gagolishvili

With a view to synthesizing heat-resistant polymers, we performed the heterofunctional condensation (HFC) of α,ω-bis (aminodimethylsilil) tetramethyl- cyclodisilazanes with terephthaloyl chloride. The synthesized polymers are elastic products in light color. Their elasticity increases with an increase in cyclodisilazane fragments in the polymer chain. At temperatures of 360 to 3800C, there starts slow polymer degradation, while fast degradation occurs at a temperature of 400 to 4500C. We also performed the HFC of α,ω-bis (aminodimethylsilil) tetramethyl- cyclodisilazanes with α,ω-bis ( -carboxyethyl) dimethylhexanes. The synthesized products are caoutchouc-like products, as they contain pliant siloxane and cyclodisiloxane fragments. They have quite high thermal stability. The stability is impacted on by an increase in the dimethylsiloxane block in the copolymer chain. Polymers are resistant at temperatures of 510 to 5500C. At these temperatures, there starts their slow degradation. The thermal stability of polymers is not impacted on by an increase in the share of silazane cycles in the chain.

36-59

Authors: Oleg Mosin, Ignat Ignatov, Dmitry Skladnev, Vitaly Shvets

By the method of microbiological synthesis were obtained and analyzed by electron impact mass-spectrometry the evaluation of 2H and 13C enrichment levels of secreted amino acids of methylotrophic bacteria Brevibacterium methylicum and Methylobacillus flagellatum, and amino acid resigues of total protein obtained from media contaning as a sourse of stable isotopes [2H]methanol, [13C]methanol and 2H2O. It was also performed the incorporation of L-[2,3,4,5,6-2Н]phenylalanine, L-[3,5-2Н]tyrosine and L-[2,4,5,6,7-2Н]tryptopan in bacteriorhodopsin synthesised in purple membranes of photo-organotrophic halobacterium Halobacterium halobium ET 1001. For mass-spectrometric analysis the multicomponential mixures of 2H- and 13C-labeled amino acids, derived from cultural media and protein hydrolysates after hydrolysis in 6 M 2HСl (3 % phenol) and 2 M Ва(OH)2 were modified into N-benzyloxycarbonyl-derivatives of amino acids as well in methyl esters of N-dansyl-derivatives of amino acids, which were preparative separated using a method of reverse-phase HCLP. 2H- and 13C-labeled amino acids represented the mixures differing in quantities of isotopes incorporated into molecule. The levels of 2H and 13С enrichment of secreted amino acids and amino acid resigues of protein were found to vary from 20,0 atom% to L-leucine/isoleucine up to 97,5 atom% for L-alanine depending on concentration of 2H- and 13C-labelled substrates.