Nowadays, leather industry is suffering from low quality of raw materials, usage of efficient and environment unfriendly materials. This situation may be corrected by upgrading the existing or developing new technologies using efficient chemical materials, such as polymeric compounds. The aim of the study was to improve the leather dyeing processes through usage of water-soluble polymers derivatives of acrylic and maleic acids in the direction of simplification and reduction of processing materials consumption, ensuring high product quality, establishing the mechanism of interaction between these materials and collagen. The reactions in the "collagen-polymeric compounds-dye" system were studied using IR-spectroscopy. The fiber preparation from the untanned leather industry waste was used for the collagen prototype. The data obtained show correlation between interaction type in the system under study as well as leather properties and processing conditions. We have established a positive effect of investigated polymers on the physical, mechanical, and hygienic leather properties. It can be explained through their ability to be absorbed on the surface of the derma structural elements; to interact with them and other applied reagents (tannins, dyes etc.), there by promoting structure formation and improving product quality.

In the present time, despite all the advantages, the use of chrome-based tanning components are reduced or excluded in leather production, primarily, because of its toxicity and ineffective use of the agents. The new chrome-free tanning method has been offered to replace ship skin pickling with polymeric treatment of rawhide and subsequent titanium tanning. Ammonium titanyl sulfate is used as a tanning agent while polymaleate -as a polymeric material. It has been established that the replacement of pickling with polymeric treatment improves diffusion and exhaustion of titanium tannins from the solution, which, in turn, ensures the formation of the Wet-White leather structure and its thermostability. Polymer-titanium tanning system not only increases the consumption of tanning agents, reduces treatment duration, but also improves physical and mechanical properties of finished leather: strength, elongation, volume yield, thickness yield, porosity, etc. This was confirmed by the results of scanning electronic microscopy, which prove that a tanning method affects morphological changes in leather structure and uniform distribution of tannin into the derma.

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The study examines the influence of artificial aging on the stability of collagen within the parchments. Aging of the parchments was generated by heating at 70°C in a dry oven for 72 h as well as by keeping the parchment samples in the solution of artificial sweat. Sodium dodecyl sulfate polyacrylamide gel electrophoresis and size-exclusion chromatography were utilised to investigate the state of proteins within the parchment samples after exposure to heating and artificial sweat. The study has shown that the accelerated aging of the parchment results in marked change of protein and peptide concentrations, release of collagen chains, as well as leads to the alteration in the peptide compositions. KEY WORDS: parchment, collagen, accelerated aging, electrophoresis, chromatography STAREA COLAGENULUI DIN PERGAMENT SUB INFLUENŢA ÎMBĂTRÂNIRII ARTIFICIALE REZUMAT. Studiul examinează influenţa îmbătrânirii artificiale asupra stabilităţii colagenului din pergamente. Pergamentele au fost îmbătrânite prin încălzirea la 70°C într-un cuptor uscat timp de 72 de ore, precum şi prin menţinerea probelor de pergament în soluţia de transpiraţie artificială. S-au utilizat electroforeza în gel de dodecil sulfat de sodiu-poliacrilamidă şi cromatografia de excludere a mărimii pentru a investiga starea proteinelor din probele de pergament după expunerea la încălzire şi transpiraţie artificială. Studiul a arătat că îmbătrânirea accelerată a pergamentului are ca rezultat o schimbare vizibilă a concentraţiilor de proteine şi peptide, eliberarea lanţurilor de colagen, precum şi modificarea compoziţiilor peptidice. CUVINTE CHEIE: pergament, colagen, îmbătrânire accelerată, electroforeză, cromatografie L'ETAT DE COLLAGENE DANS LE PARCHEMIN SOUS L'INFLUENCE DU VIEILLISSEMENT ARTIFICIEL RÉSUMÉ. L'étude examine l'influence du vieillissement artificiel sur la stabilité du collagène dans les parchemins. Les parchemins ont été vieillis par chauffage à 70°C dans un four sec pendant 72 heures, ainsi que par conservation des échantillons de parchemin dans la solution de transpiration artificielle. L'électrophorèse en gel de polyacrylamide contenant du dodécysulfate de sodium et la chromatographie d'exclusion stérique ont été utilisées pour étudier l'état des protéines dans des échantillons de parchemin après une exposition au chauffage et à la transpiration artificielle. L'étude a montré que le vieillissement accéléré du parchemin entraînait un changement visible des concentrations de protéines et de peptides, la libération de chaînes de collagène et une modification des compositions de peptides. MOTS CLÉS: parchemin, collagène, vieillissement accéléré, électrophorèse, chromatographie

Key words:ABSTRACT Biotechnological preparation Collagen containing wastes Chemical analysis microbiological and IR-spectroscopic researches Leather industry is one of the main producers of collagen-containing raw materials. Therefore, effective recycling of these raw materials into marketable products is a pressing problem not only for leather industry but also for other fields of human activity and environmental ecology. Among the most important areas of using collagen-containing materials, it is possible to product the additives and emulsions containing of protein and fat component; the production of multifunctional drugs and structured products (type of extrudate and crisps); gelatine manufacturing; production of preparations for fragrance and cosmetics industries, veterinary medicine, medicine, leather manufacturing etc.It has been investigated a new Ukrainian collagen-containing preparation, obtained by biotechnology, from nontanned leather wastes (raw material from bovine hides in the form of macromolecular-purified fibrous product). Since the content of toxic elements in the preparation is less than the maximal acceptable level, and microbiological studies indicate the absence of pathogenic microflora it can be ascribed to non-toxic, environmentally friendly products.The size of particles in collagen preparation was assessed using microscopy. Chemical analysis identified chemical composition (moisture content, as well as protein, fats and minerals content). The presence of different functional groups in the structure of investigated preparation was detected by IR-spectroscopy. Based on the results of experimental data it is assumed the possibility of practical use of this new collagen-containing preparation as secondary raw materials in many sectors of national economy.