Browsing by Subject "Leather chemicals"
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Item Characterization of leather powder using inverse high performance liquid chromatography(Texas Tech University, 2001-12) Huang, HongjunLeather powder represents a waste leather material. which has been the focus of value-added product utilization studies for the past two decades. It is hereby studied with inverse high performance liquid chromatography. The surface chemistry of this material is detailed through chromatographic elution studies of a series of solute probes with mobile phases of different pH. Probe molecules, including acids, bases. and neutral markers, were used to study the amino and carboxyl functional groups. as well as hydrophobic sites on leather powder. Capacity factor. chromatographic efficiency, recovery and statistical moments were determined for selected probe molecules. A unique, flow-through method for leather powder characterization has been developcd.Item Extraction of post-tanning chemicals from leather wastes(Texas Tech University, 2000-12) Arcot, G. SenthilkumarThe disposal of leather scraps produced by the footwear industry is a difficult and expensive task due to their undesirable and adverse effects on the environment. It will be profitable for the shoe industry to convert this waste into value added products. This thesis investigated the feasibility of employing supercritical fluid extraction (SFE) technique in the pre treatment phase of gelatin extraction process (Taylors' Process). The current study had three experimental phases namely sample preparation, extraction of components from the sample and quantification of the extracted components. Three methods (one-step process, two-step process and modifier-assisted SFE process) were used in the extraction of components from leather samples. In the one-step process, the post-tanning chemicals were extracted using SFE. In the two-step process, Soxhlet extraction followed by SFE was employed in extracting the post-tanning chemicals. Preliminary SFE experiments were conducted to determine optimum extracting conditions for the extraction of post-tanning chemicals from leather scraps. The third method was similar to one-step process, except that instead of using carbon dioxide as extracting solvent modified carbon dioxide was used. The modifiers used were methanol and phenol. This research was able to introduce SFE as an option for extracting post-tanning chemicals from leather scraps by optimizing the extraction conditions and comparing the results with conventional Soxhlet extraction technique.Item Multidimensional instrumental analysis of wet-blue leather hydrolysate(Texas Tech University, 2002-12) Martinelango, ParamakalyaniThe U.S. leather industry generates more than 60,000 metric tons of chromium containing solid wastes every year, of which roughly half is attributed to chrome shavings. Much of these have been disposed in landfills. Owing to increasing environmental concern and a decrease in the number of disposal sites, extensive research has been done on the recovery of protein (collagen) and chromium from the shavings. The main objective of this work is to obtain a deeper insight into magnesium oxide (MgO) hydrolysis of chrome shavings and to look at newer ways of exploiting the products. Collagen hydrolysates are studied by various analytical techniques such as electrophoresis, chromatography and mass spectrometry. MgO hydrolysis produced fractions with molecular weight and charge heterogeneity as seen from sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), isoelectric focusing (lEF), capillary zone electrophoresis (CZE) and reverse phase-high performance chromatography (RP-HPLC). Consistent and complementary results are obtained from electrophoresis and chromatography. We created a multidimensional analytical mediodology to acquire a thorough, molecular-level characterization of these hydrolysates. The enhanced resolution space provided by these different techniques yields definitive and the most complete results, to date. The results obtained in this work provide useful information on the characteristics of the hydrolysates. This information will be helpful to develop better value-added applications for the chrome shavings. Such value-added products create a demand for the chrome shavings that will keep them out of the landfill.