Stock analysis of additives synthesis via vapor-phase chromatography containing liquid crystals

Via vapor-phase chromatography 2-tiophentiol and the mixtures of individual xanthogenates, which are the stock of additive synthesis have been analyzed. Isomeric composition of high boiling aromatic hydrocarbons has been separated through vapor-phase chromatography. n,nꞌ-dyetoxiazoxybenzol and dygeptylphenyl ethers of phenyldicarbon acids, which are applied to the glass capillary columns have been used as a liquid stationary phase. The water vapor of moving carrier was used instead of the gas-carrier of nitrogen, which allowed to reduce the durability of the analysis and to improve the seperation efficiency. The main parameters of vapor-phase chromatography have been studied during the stock analysis as well. The retention time, the height of theoretic trays and rates of assimetry of analyzed compounds have been calculated.

Configuration and isomeric composition of rubbers: determination by 1H and 13C NMR spectroscopy

Nuclear magnetic resonance (NMR) spectroscopy is a convenient method for studying the structure and isomeric composition of diene rubbers. A simple and reproducible method is proposed for determining the content of both rubber and impurity compounds, which does not require additional sample preparation. Formulas for calculating the composition of industrial products and determining the initial substances are given, the applicability of the analysis method is confirmed. In the process of work, rubbers of various brands were analyzed, their configuration-isomeric composition was established. It was found that the integration ranges given in the literature earlier and the methods for processing 1H NMR spectra differ, the signals of the groups often overlap in the spectrum, which increases the calculation error. It is shown that the structure of the industrial products under study is established most accurately by carbon proton resonance spectroscopy, and the calculation based on the PMR spectra allows confirming the data obtained with sufficient accuracy.