Common tormentil tannins as tanning material for leather processing

У роботі представлені результати дослідження властивостей танідів, отриманих з кореня перстачу прямостоячого (Potentіlla erecta) і властивості ними видублених шкір. Визначено, що ці таніди відрізняються високою спорідненістю до колагену. Шкіра, видублена цими танідами відрізнялася коричнюватим забарвленням, лицьовою поверхнею без стяжки, високою міцністю при розтягуванні й низьким відносним видовженням. Температура зварювання шкір досягала 73 oС.В работе представлены результаты исследования свойств таннидов, полученных из корней Лапчатки прямостоячей (Potentilla erecta), и свойства ими выдубленных кож. Определено, что эти танниды отличаются высоким сродством к коллагену. Кожа, выдубленная этими таннидами, отличалась коричневатой окраской, лицевой поверхностью без стяжки, высокой стойкостью при растяжении и малым относительным удлинением. Температура сваривания кож достигала 73 oC.Presented research devoted for investigation of Common tormentil (Potentilla erecta) tannins properties and tanning peculiarities. It was established that tormentil tannins have high affinity to collagen. Leather tanned with tormentil tannins distinguished by brownish grain colour, grain was not shrunk, and it had high tensile strength but low relative elongation. Shrinkage temperature of leather tanned with tormentil tannins reaches 73.6oC, and it is almost same like after tannins with modified vegetable tannins or synthans

Immunizacja wełny metaglinianem sodu

Since the environmental requirements for leather manufacture as well as for other industry branches are becoming stricter, investigations of unhairing have been directed towards conditions of the process which allow the saving of hair: enzymatic unhairing or unhairing with hair immunization conventionally achieved by using lime and sodium sulphide. The problem is that lime forms a big quantity of liquid waste which contains lime sludge polluted by sulphides and protein degradation products. The research is devoted to the replacement of Ca(OH)2 as hair immunization material with some other soluble non-hazardous material with a similar immunization effect. The preliminary tests showed that alkaline sodium aluminate suits this purpose very well. Its immunisation efficiency increases with prolonged treatment duration and increased concentration of the treatment solution. Treatment with 20 g/l of sodium silicate solution for 3 h allows to reach a high immunization ability almost the same as that of calcium hydroxide under the same conditions. The immunisation effect lasts when the pH is approx. 13.Ponieważ normy dotyczące ochrony środowiska w przemyśle skórzanym, jak również w innych gałęziach przemysłu stają się coraz bardziej restrykcyjne, badano immunizację wełny wodorotlenkami wapnia i potasu oraz metaglinianem sodu, badając poziom degradacji wełny po obróbce. Efekt immunizacji został oszacowany na podstawie zmian utraty masy wełny i zawartości azotu w roztworze. Potwierdzono, że metaglinian sodu jest skutecznym środkiem immunizującym. Skuteczność immunizacji metaglinianem sodu zwiększa się wraz z wydłużeniem czasu obróbki i zwiększeniem stężenia roztworu

Alkali-free method of hide preparation for tanning

Usually, beamhouse processes are carried out by varying a medium from strongly alkaline (unhairing-liming) up to strongly acid (pickling). This study is designed to develop a preparation of hide for tanning via processes that avoid a sharp change of hide pH. Enzymes active in acid medium are employed for hide unhairing in a buffer system containing 2.5% acetic acid and 0.3% sodium acetate. An oxidative treatment with peracetic acid then allows the complete removal of residual hair and scud. During both processes, unhairing and oxidative treatment, the opening of the derma structure occurs: 13.3-14.6g of non-collagen proteins are removed and amount of dermatan sulphate decreases by 35%. The hide obtained can be chromed directly after the above processes and subsequent treatment with sodium chloride solution omitted conventional pickling. The pH of the hide varies in the range of 8.3-3.7 during the processes of preparation for tanning

Application of Fourier transform infrared (FTIR) spectroscopy in the characterization of tannins.

A review of vibrational frequencies reported for tannin molecules is provided to create a database with typical fingerprints for different types of tannins. This will provide researchers working on vibrational spectroscopy applications and technicians a fast, easy, and reliable method to assess the quality and authenticity of these compounds, both extracted in laboratories and provided from commercial sources. The widespread use of these compounds has highlighted the need for a systematic characterization of the vibrational frequencies and molecular fingerprints for their identification and discrimination. According to our knowledge, this is the first systematic collection of typical peak frequencies for tannins, which can be applied in several research fields and technological applications

Preparation of Polymeric Micelles of Poly(Ethylene Oxide-b-Lactic Acid) and their Encapsulation With Lavender Oil

Nanoparticles comprised of the poly(ethylene oxide)-b-poly (lactic acid) diblock copolymer (PEO-b-PLA) with and without the incorporation of lavender oil were prepared by nanoprecipitation. Diblock copolymers based on a fixed PEO block (5KDa) and two different PLA segments (4.5 or 10KDa) were used. The morphology, encapsulation efficiency, essential oil-polymer interaction and the release kinetics of the active agent in the nanoparticles, were evaluated. The hydrodynamic radius of the nanoparticles determined by light scattering was affected by the size of the poly(lactic acid) (PLA) block. The lavender essential oil encapsulation efficiency (at a concentration of 0.4 µL mL-1) determined by UV-VIS spectroscopy was in the range of 70-75%. The in vitro release suggests that the polymeric barrier is able to control the oil release