Leather particles

Types aluminum fiber, aluminum hydroxide, antimony trioxide, calcium caibonate, carbon black, carbon fiber, hollow glass beads, kaolin, magnesinm hydroxide, mica, sand, silica, silica carbide, talc, waste leather particles, wollastonite, wood fiber, wood flour, zeolite... 

Wood-filled PVC has inferior mechanical properties because of lack of interaction. Treatment of wood filler with aminosilane improves acid-base interaction between filler and polymer to the extent that impact strength and tensile properties of composite are improved over unfilled PVC. Tensile properties of PVC were deteriorated when leather particles were used as a filler. But, after filler particles were treated with ethylene-vinyl acetate copolymer, a coating was produced on the surface of filler particles that promoted adhesion with PVC and improved mechanical properties.These are some recent examples of many applications of filler preparations to improve its interaction with PVC. 

Separation of amines was realized in an ODS column (250 x 3 mm i.d. particle size 5 /tm) at 30°C. The flow rate was 0.3 ml/min and amines were detected at 280 nm. Solvents A and B for gradient elution were ACN and 3 mM phosphate buffer (pH = 7). The gradient started with 15 per cent A for 2 min then to 60 per cent A in 50 min. Chromatograms illustrating the separation of amines are shown in Fig. 3.72. It was established that the recoveries of both SFE and MAE were higher than those of traditional solvent extraction, therefore, their application for the analysis of carcinogenic aromatic amines in leather is highly advocated [140],... 

Uses. Manufacture of formaldehyde resins, which are used as adhesives in particle board, plywood, and insulating materials countertops and wall paneling coating to fabrics to impart permanent press characteristics manufacture of rubber, photographic film, leather, cosmetics, embalming fluids, insulation disinfectants and fumigants... 

Preparation op the Hides.—The tanner, previous to submitting the hides, skins, or kips, to the true tanning process, is under the necessity of subjecting them to one or more preliminary operations, with the view of removing dirt, particles of flesh, and in most cases tho hair and epidermis and the manner in which these are effected is of great importance, as mueh of the success of the subsequent process, and, consequently, of the quality of the leather, depends upon it. 

PORE. I A minute cavity in epidermal tissue as in skin, leaves, or leather, having a capillary channel to the surface that permits transport of water vapor from within outward but not the reverse. 2. A void of interstice between particles of a solid such as sand minerals or powdered metals, that permits passage of liquids or gases through the material in either direction. I11 some structures, such as gaseous diffusion barriers and molecular sieves, the pores ate of molecular dimensions, i.e 4-10 A units. Such microporous structures are useful for filtration and molecular separation purposes in various industrial operations. 3. A cell in a spongy structure made by gas formation (foamed plastic) that absorbs water on immersion but releases it when stressed. 

The polyurethane (PU) can be considered an environment-friendly material because the urethane bond resembles the amide bond, which implies possible biodegradability. It can be used in various elastomer formulations, paints, adhesives for polymers and glass, and artificial leather as well as in biomedical and cosmetic fields. Polyurethane spheres were prepared from 20/40% of PU prepolymer solution in xylene [91]. PU droplets were formed in water with the SPG membrane of different pore size (1.5-9.5 pm) and then polymerized to form the final microspheres. Finally, spherical and solid PU particles of 5 pm were obtained after the removal of the solvent. In another study, Ma et al. reported the formation of uniform polyurethane-vinylpolymer (PUU-VP) hybrid microspheres of about 20 pm, prepared using SPG membranes and a subsequent radical suspension polymerization process [92], The prepolymers were solubilized in xylene and pressed through the SPG membrane into the continuous phase containing a stabilizer to form uniform droplets. The droplets were left for chain extension at room temperature for some hours with di- and triamines by suspension polymerization at 70 °C for 24h. Solid and spherical PU-VP hybrid particles with a smooth surface and a higher destructive strength were obtained. 

These microporous composites are tough, but soft and very conformable, leather-like films, the chemical and physical properties of which are determined primarily by the choice of the major component (i.e. the enmeshed particle, usually more than 85% by weight) [121-124], The minor component (PTFE), however, confers physical integrity upon the film without affecting adversely the chemical properties of the major component. Since the enmeshed particles are distributed... 

The glass plates were first cleaned with chamois-leather dipped in 3 % H2O2 and afterwards with alcohol. Then the plates, the plate Ai being fixed in the frame B, were quickly but carefully brought together in such a way tiiat interference colours became visible. If this could not be done very easily, dust particles were still present between the plates and cleaning was repeated. 

Aside from softening, a smaller amount of oils and fats as detergents are also used in preliminary cleaning of the raw skins and hides to suspend lime particles, buffer the alkaline solution that removes the epidermis and hair, and suspend these materials when they come off to remove grease to tan certain types of leather and to control the penetration of dyes. 

Aqueous dispersions of poly(vinyl acetate) and vinyl acetate-ethylene copolymers, homo- and copolymers of acrylic monomers, and styrene-butadiene copolymers are the most important types of polymer latexes today. Applications include paints, coatings, adhesives, paper manufacturing, leather manufacturing, textiles and other industries. In addition to emulsion polymerization, other aqueous free-radical polymerizations are applied on a large scale. In suspension polymerization a water-irnrniscible olefinic monomer is also polymerized. However, by contrast to emulsion polymerization a monomer-soluble initiator is employed, and usually no surfactant is added. Polymerization occurs in the monomer droplets, with kinetics similar to bulk polymerization. The particles obtained are much larger (>15 pm) than in emulsion polymerization, and they do not form stable latexes but precipitate during polymerization (Scheme 7.2). 

The infrared spectrum of the sample can be obtained either by an alkali halide pressed pellet technique or by different reflection techniques. The sample powder is ground into small particles and 3-10 mg are mixed uniformly and pressed with approximately 300 mg of alkali halide powder (such as sodium chloride (NaCl) or more commonly potassium bromide (KBr)) by means of the apparatus electrohydraulic press with an evacuable KBr die. The quantity of the leather powder used for the pellet should be determined so that the spectrum that will be obtained has an absorbance of the strongest band of around 1 unit. The transmission spectrum can be obtained by placing the thin and uniformly pressed pellet of leather powder-KBr perpendicular to the infrared radiation. 

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