Smirnov P.R.

CHEMICAL TRANSFORMATION OF TECHNICAL FIBER OF FLAX, HEMP AND JUTE TO CELLULOSE AND THEIR PYROLYSIS

Taking into account the chemical composition and morphological features the tech-nical high purity fibers of flax, hemp and jute were studied as a new potential source of cellu-lose. The kinetics of the oxidation-hydrolytic method was shown for producing pulp from technical jute fibers in an aqueous alkaline medium containing the active components. The degree of removal of non-cellulosic components from technical jute fibers increases with the concentration of sodium hydroxide in an aqueous medium containing active additives, as well as with the increase in processing time and temperature. With the methods of chemical analysis, wide-angle X-ray scattering, FT-IR spectroscopy, electron microscopy the chemical composition and the supramolecular structure of the samples was studied. The thermal stabil-ity of the technical fibers, flax pulp, jute and hemp were determined. It was found that the ob-tained samples of linen, hemp and jute cellulose have I monoclinic modification.

2016, Т. 59, № 6, Стр. 97‒104

ON ORIGIN OF SMALL-ANGLE MAXIMA ON X-RAY SCATTERING INTENSITY CURVES OF AQUEOUS ELECTROLYTE SOLUTIONS

At the X-ray diffraction analysis of high concentrated aqueous electrolyte solutions with multiply charged cations small angle maxima or pre-peaks are arising on scattering in-tensity curves (IC) (at about 1 Å). Their existence is connected with structural appearance so called “intermediate-range order”. Previously for explanation of this phenomenon some not completely correct hypotheses were suggested. On the example of raw X-ray diffraction data of some aqueous electrolyte solutions in wide concentration range collected by using MoKα-radiation the dynamic of small angle maxima shape change has been studied. It has been noted that pre-peaks absence on IC of cesium iodide and chloride solutions is not supporting the hypothesis about pure small angle contribution from “heavy” ions [1, 2]. In the case of Al3+, Sc3+, Fe3+ chloride solutions relative similarity of IC shapes has been noted for solutions with similar concentrations.

2016, Т. 59, № 6, Стр. 72-77
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