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In this study, collagen hydrolyzate was obtained from bovine shaving wastes of leather production with the alkali hydrolysis reaction. Total amino acid, total carbon and total nitrogen amounts of liquid collagen hydrolyzate (CH) were determined. Fourier-transform infrared spectroscopy (FTIR) characterization of collagen hydrolyzate was performed. Obtained CH was emulsified with hydrogenated castor and amino functional silicone oils to prepare lubricating protein filler (LPF). Particle size and zeta potential of the LPF were analyzed. 10%, 15%, and 20% LPF was used in the retanning/fatliquoring process of chromium tanned bovine leathers. Performance characterizations of leathers treated with LPFs were carried out with tensile strength, tear strength, filling efficiency, light fastness, shrinkage, and denaturation temperature analyses. Moreover, bounded fat content in leather was also determined. Results showed the increased thermal stability, strength performance and good filling effect in leather by application of the prepared LPF. Consequently, LPF had a good potential as natural retanning/fatliquoring agent via achieving reuse of the solid leather wastes and providing satisfactory leather properties and cleaner production by one product itself.

Leather is composed of a three-dimensional weave of collagen fiber bundles. Collagen is a fibrous protein well organized in the formation of skin as building blocks. Leather production involves serial operations where the tanning plays the major role in improving the durability of leather products by stabilizing the triple helical structure of collagen matrix. In the leather-making industry, different tanning agents are used to produce different kind of leather goods. These tanning agents have varied efficiency on the stabilization of collagen. In this study, thermal stability of the leathers tanned with most commonly used tanning agents was evaluated by conventional shrinking test (CST) and differential scanning calorimetry (DSC) methods. The results showed that the thermal stability of leathers varied by the type of tanning agent which were in accordance with theoretical approaches. A distinct correlation was also observed between CST and DSC results of the tanned leathers.

Leather processings involved in isolation in pre-tanning stages generate large volumes of solid wastes and high strength wastewater which are major source of environmental pollution characterized by chemical oxygen demand (COD), biological oxygen demand (BOD), total dissolved solids (TDS), total suspended solids (TSS), chromium (III) and phenolics with high pH, strong odor and dark brown color. Leather industry wastewaters with high organic content and pollution load are generated from pre-tanning processes. Conventional pre-tanning process utilises chemicals which attributes to 50-60% of pollution load and alkaline effluent discharge of 70-80% toxicity. In our study, the best practices modelling and eco-compatible process shifts were the objectives for the decrement in high pollution load of large effluent portion for leather industry. Soaking, immunization and liming processes were carried out with reductive chemical additives and surfactants, fibre opening auxiliaries, enzyme based and enzyme assisted chemicals in the factories as an eco-friendly designed recipe. Studies were conducted in Bursa Leather Park, Turkey. The results revealed the advantages of time saving, cost effectivity and minimized pollution load compared to conventional process. Moreover, the designed process uses lower amount of alkaline chemicals and water, gives a very high quality pelts with open grain and yield in 50-55% lime split output with 2.2-2.4 mm thicknesses. © 2019 by the author(s).

The surface characteristics of many biomedical devices, tools, implants, therapeutic vehicles, etc., are of critical importance in many areas as they have direct contact with human cells, tissues, and other biological systems. Regarding the developments in nanosciences within the last decade, nanocoatings and nanostructured coatings have been presented as a versatile approach for modification of biomedical surfaces to improve their properties and functionality. This chapter deals with nanocoating preparation methods and focuses on their applications in the biomedical field.

7th International Conference on Advanced Materials and Systems -- OCT 18-20, 2018 -- Bucharest, ROMANIA, WOS: 000464905000042, The main causes of leather goods damage is fading as well as the damages caused by sweat and body grease, mechanical deformation and ageing. Tanning agents have varied efficiency on the UV durability and stabilization of collagen. It is because they have different bond strengths and binding mechanisms with leather. In this study, light fastness properties of the leathers tanned with the most commonly used white tanning agents were aimed to evaluate by using ATLAS XENOTEST ALPHA+ test instrument according to ISO 105-B02 standard test method and the leathers tanned with chromium tanning agent were used as a comparison. Blue wool test references were evaluated according to grey scale, and the evaluation of the color change for the tanned and dyed leathers against UV application of an artificial light source representative of natural daylight was carried out. In addition to light fastness test, colorimetric measurements of the treated samples and color changes before and after the UV application were also spectrophotometrically determined by Konica Minolta CM-3600d test device. The results showed that chromium tanned leathers provided the best light fastness results compared to other leathers tanned with white tanning materials. Zirconium and phosphonium tanned leathers had the same values and better than aluminum and vegetable tanned leathers., Minist Res & Innovat, Natl Res & Dev Inst Textile & Leather, Div Leather & Footwear Res Inst, Ege University Scientific Research Project Department DirectorateEge University [17MUH007]; Turkey Prime Ministry State Planning OrganizationTurkiye Cumhuriyeti Kalkinma Bakanligi [07DPT001], The authors would like to thankEge University Scientific Research Project Department Directorate (Project No: 17MUH007) for financial support and Turkey Prime Ministry State Planning Organization (07DPT001) for equipment support. Also the authors would like to thank to Tezcan Leather (Usak, Turkey) for providing the pickled sheepskins.

Valonea extract is a natural tannage widely applied in leather industry which is produced via conventional hot water extraction method. On the otherhand more environmental friendly methods have started to be used in extraction technology recently. Present paper reports on the effect of different extraction methods on the properties of valonea extracts. For this purpose, conventional solvent extraction (CSE) (methanol/water mixture), supercritical CO2 (scCO2) extraction and pressurized fluid extraction (PFE) (water/CO2 binary system) techniques have been employed on valonea and the obtained extracts have been characterized. Molecular weight of the tannins was determined by gel permeation chromatography (GPC), particle size was examined by Malvern Zetasizer instrument, chemical structure by Fourier Transform Infrared Spectroscopy (FTIR). Tannin content was also examined and the results were compared with commercial valonea extract (CVT). The results showed that especially particle size of the tannins was affected by the applied extraction method and the smallest particle size was obtained by PFE method as 505.3 nm compared to commercial tannin as 983.0 nm of average particle size. PFE method was also provided more uniform extract according to the polydispersity index values. GPC and FTIR analyses showed slightly differences on the characteristics of tannins.

Deri üretiminde özellikle ıslatma-yumuşatma, yağ giderme, yağlama ve boyama gibi proseslerde çeşitli yüzey aktif maddelerin etkilerinden faydalanılmaktadır. Bununla birlikte ticari ve teknik öneme sahip yüzey aktif maddeler olan alkil fenol etoksilatlar (APEOs) insan sağlığına ve çevreye olan toksik etkileri sebebiyle kullanımları sınırlandırılmıştır. Bu çalışmada küçükbaş derilerin boyama işleminin homojen ve yüksek tüketimli bir şekilde gerçekleştirilebilmesi için APEO içermeyen yüzey aktif madde karışımları hazırlanarak boyama üzerine olan etkinlikleri belirlenmiştir. Alkil fenol etoksilat içermeyen boya egalizatörleri ile işlem görmüş deri örneklerinin renk ölçümleri Konica Minolta CM-3600d marka spektrofotometre, boyarmadde tüketimleri ise Shimadzu UV-1601 PC UV-Visible marka spektrofotometre kullanılarak analiz edilmiştir. Mamul hale gelen derilerde ışık haslığı analizleri ISO 105-B02 standart metoduna göre yapılmış ve sonuçlar kıyaslamalı olarak incelenmiştir. Ayrıca elde edilen derilerin APEO içerikleri de belirlenmiştir. Araştırma sonuçlarına göre; hazırlanan boya egalizatörlerinin banyo tüketimi, elde edilen renk ve ışık haslığı değerleri açısından ticari olarak kullanılan APEO içerikli egalizatörler ile benzer sonuçlar verdiği ve APEO içermeyen yüzey aktif maddelerin deri üretiminde kullanılmasıyla ekolojik uyumlu hedeflenen ürünlerin üretilebileceği ortaya konmuştur., In leather production, various surfactants areused in the processes such as soaking, degreasing, fatliquoring and dyeing.However, alkylphenol ethoxylates (APEOs), commercial and technical surfactant,have been restricted due to their toxic effects on human health andenvironment. In this study, the APEO-free surfactant mixtures wereprepared to determine the effectiveness of the dyeing process in order toachieve the homogeneous and high consumption of the dyeing process ofsheepskins. Color measurements of the leather samples treated with APEO-freedye levelling agent were analyzed using Konica Minolta CM-3600dspectrophotometer and dyestuff consumption were determined with the ShimadzuUV-1601 PC UV-Visible spectrophotometer. Light fastness analyses were carriedout according to ISO 105-B02 standard test methods and the results werecompared. The APEO contents of the dyed leather were also determined. Accordingto the results; prepared dye levelling agents were provided the similar resultswith APEO-based surfectants in terms of float uptake, obtained color and lightfastness values and thus, producibility of eco-benign leather products wasrevealed by using the APEO-free surface active agents.

International Conference on Environment, Chemical Engineering and Materials (ECEM) -- JUN 27-29, 2017 -- Transylvania Univ Brasov, Brasov, ROMANIA, WOS: 000426289700006, Copolymers bearing reactive functional groups with controlled molecular weights are of importance since they can be used in many fields such as composites, coatings, membranes, catalysis, biology, optoelectronics, pharmaceuticals, etc. In the present study low molecular weight copolymers based on butyl acrylate (BA) and methyl methacrylate (MMA) in combination with reactive functional monomers of vinyl trietoxysilane (VTES), 3-trimetoxysilylpropyl methacrylate (TMSPMA) and glycidyl methacrylate (GMA) were synthesized via RAFT mini emulsion technique using 2-cyano 2-propyldodecyldithiocarbonate as CTA agent. The results showed that the average molecular weights of copolymers were close to the theoretical values. On the other hand, PDI values were found to be higher than conventional RAFT polymers. The particle sizes of the latexes were small with very homogenous distributions and good stability. FTIR, H-NMR and TGA results verified the success of copolymer syntheses., Scientific and Technological Research Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [115M650], The authors acknowledge the financial support from The Scientific and Technological Research Council of Turkey (TUBITAK), Project No: 115M650.

In this study, ozonation as an environmentally friendly bleaching method was studied for decolorization of leather products. The effect of ozonation time (3, 5, 10, 15 and 30 min) and water pick-up value (WPV) (0%, 20%, 40%, 60%, 80% and 100%) were investigated on decolorization effect. For this aim, the color measurement and tensile strength tests were performed, and also structural changes were determined by scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FTIR) after ozonation process. The results of color measurements showed that 30 min for ozonation and 60% WPV were optimum parameters to obtain maximum decolorization effect. SEM images of the ozonated leathers showed some deformations on the collagen fibers and resulted with the slightly decreases in tensile strength of the products. On the other hand, decreases in the tensile strength values were not statistically important levels.

In this study, reproducibility of the cosmetic purpose antimicrobial emulsion formulations containing collagen hydrolysate by taking the advantage of the antimicrobial features of the industrial essential oil plants including Thymus vulgaris , Origanum onites, Eucalyptus globulus and Mentha piperita was investigated. The formulations produced for this purpose were subjected to the microbiologic testings with respect to the disc diffusion method. As the result of the studies, the formulations containing O. onites and T. vulgaris were found to demonstrate the highest antimicrobial activity. In addition to this, the emulsions were subjected to the viscosity and particle size analysis and examined in organoleptic terms as well.

In this research, the extracts obtained from various natural products (hazelnut shells, thyme, olive shoots, and walnut leaves), which are indicated to have antioxidative characteristics, which are used during the retanning stage of leather manufacturing and their effects on chromium(VI) formation in leather was examined. Finished leathers were exposed to ageing conditions for 24h at 80oC and for 24h and 72h at 80oC under UV in order to enable chromium(VI) formation in the leathers. Chromium (VI) amounts in each leather sample were measured with a Shimadzu UV-1601 PC UV-Visible spectrophotometer at 540 nm according to the ISO/FDIS 17075 standard method, and how each extract affected chromium (VI) formation in leather was examined. According to the findings of the research; Coridothymus capitatus, Olea europaea, Corylus avellana, and Juglans regia extracts, which were used during the retanning stage of leather manufacturing, significantly reduced chromium(VI) formation in the leather under all three ageing conditions. The best reduction was obtained with Coridothymus capitatus extract in the ratio of 89.24% under the ageing condition of 24h/80oC. It is recommended that different extraction methods, different natural extracts, and different ageing conditions be carried out in the future are to optimize the results of the current study.

In recent years, finishing has begun introducing an extraordinary touch and appearance to the surface of leathers by surface modification. Because some superficial anomalies cannot be recovered by conventional finishing procedures, those can only be drawn on by coating techniques. Coating aims at obtaining an alluring product, which must both recover the surface anomalies and be compatible with the leather characteristics. This study is for valorization of leathers with inferior quality, which contain surface defects, thereby being aimed at improvement of the surface characteristics. The product should have ease of use, as well as giving a fashionable look and touch to flocked fibrous surfaces, whether applied to synthetic leather types or Alcantara. For covered and patterned fibrous surfaces, the experimentations of different flock formulations with different binder types were executed, superficial characteristics were imaged with optoanalytical techniques and the fiber adhesion onto the surface was examined by abrasion tests. The research results showed that polyurethane binder had acceptable qualities for bags, footwear, garments and accessories and yielded superior binding characteristics compared to acrylic binder.