OBTAINING METHYLOL DERIVATIVES OF ALLYLTHIOUREA, HEXAMETHILENDIAMINE AND ETHYLENDIAMINE, AND THEIR USE IN THE TANNING PROCESS OF NATURAL LEATHER
The objective of this paper is the production of methylol derivatives of the organic compounds which include amine functional group, and their use in tanning process of the skin of the cattle and sheep; the use of the formed methylol derivatives for the stabilization of alkaline aluminum sulphate, the production of aluminum composite salt and the use of these substances during the aluminum and aluminum chromium tanning; complex evaluation of the improved quality of the semi-finished leather asa result of its physical, physic-mechanical and physicochemical research. The methylolderivatives of allylthiourea, hexamethylenediamine and ethylenediaminewere produced and the production process was scientifically justified for the first time.It was proved that depending on the concentration of the allylthiourea derivatives and the pHs of the environment etheric polymers are being created by polycondensation. The leather is well padded, elastic and soft, the front part of the leather is beautiful and smooth, and it is very durable.New substance allows producing natural leather which has valuable properties of being soft and padded. It means that the produced complex sault together with the collagen functional groups creates strong chemical connections. Besides, the use of methylol derivatives of allylthiourea, hexamethylenediamine and ethylenediamine during the tanning process gives white colour to leather, makes it heat resistant and water resistant. These properties allow using the produced material not only in shoes production but also in leather haberdashery industry. It is found out that using the minimum-cost chrome extractit is possible to obtain leather with improved properties which is elastic, soft, smooth and beautiful and which corresponds to national leather standards. Such a tanning method allows to reduse the consumption of chromium salts about 2,5 times. It is proved that in the tanning bath, the partial substitution of chromate by stabilized aliminate favours the improvement of quality indices of leathers and leads to the solution of some erological issues of production.