Tarassenko A. The development of the method obtaining chrome tannins from chrome-protein contained waste and their application in leather manufacture.

Dissertation is devoted to the development of the method of obtaining chrome tannins using as reducers Cr(VI) to Cr(III) chrome-protein contained waste of leather manufacture and to the method of these tannins application in leather manufacture which insures the maximum fixation of chrome compounds (III) with derma and its minimum contents in exhausted tanning solutions. The realization of this method in production conditions allows to the use these by-products more rationally and not buy the chrome tannins abroad and thus to save means. The regularity of different types of reducers influence on synthesized tannin solution properties has been established and on the base of obtained results while defining composition, chemical and physico-chemical properties of coordinative chrome compounds (III), the possible structure of these tannins has been proposed and the nature of their interaction with derma collagen has been studied. It has been shown that the internal sphere of tannins chrome complexes bothamino-acid residues and formic acid assists to the orientation of collagen fibre, causes the increase of breaking and tensile strength of chromium-plated semi-finished item.