Lead Electrodeposition from Triethylenetetramine Solution Containing Inhibitors

Lead can be efficiently electrodeposited from a number of common leaching agents such as mineral acids, carboxylic acids, and bases (hydroxides and ammonia). This paper reports the possibility to deposit lead from a triethylenetetramine solution, which is also a powerful extracting agent for lead sulfate. The high affinity of triethylenetetramine towards lead sulfate molecules makes it a promising candidate for lead recovery from various solid materials, including industrial secondary resources, sewages, and wastes. A popular methodology that can be found in the literature to recover metal from amine is based on purging a solution with carbon dioxide, resulting in lead carbonate precipitation. Here, the direct electrodeposition of lead from an amine solution was reported. The effects of the main process parameters, i.e., current density, temperature, and presence of additives, were examined to enhance the product quality. Bone glue, ethylene glycol, and polyvinylpyrolidone were used as perspective inhibitors of dendritic lead formation. It was shown that the addition of ethylene glycol can significantly reduce their formation as well as discoloration resulting from amine, producing lead metal with a 99.9% purity.

Study on Properties of Bone Glue/Polyurethane Composite Modified Asphalt and Its Mixture

Composite modification technology is widely used in the materials field. To enhance the property of polyurethane modified asphalt and realize its application in road engineering, the bone glue/polyurethane composite modified asphalt (CMA) was prepared using bone glue, polyurethane, and neat asphalt in this research. The bone glue content ranges 5–10%, that of the polyurethane is 1–5%. The relationship between the modifier’s content and the conventional properties and rheological properties of CMA was revealed by response surface methodology (RSM). The CMA performance was further verified under the optimal content of the bone glue and polyurethane. The differences of properties of styrene–butadienestyrene (SBS) modified asphalt mixture, neat asphalt mixture, and bone glue/polyurethane CMA mixture were compared and analyzed by using the pavement performance test. The results showed that the CMA’s conventional properties and rheological properties are improved. The optimal bone glue content and polyurethane content determined by RSM are 6.848% and 2.759%, respectively. The low-temperature crack resistance and water stability of the CMA mixture are enhanced, better than neat asphalt mixture and SBS modified asphalt mixture. The CMA mixture’s dynamic stability is 85% of SBS modified asphalt mixture, but it is 2.4 times of neat asphalt mixture. The result indicated that the bone glue/polyurethane CMA mixture still has certain advantages of high-temperature stability. In this research, the composite modification of bone glue and polyurethane can significantly enhance the characteristic of asphalt and asphalt mixture and provide a new method for applying and promoting polyurethane modified asphalt in road engineering.

The Influence of Animal Glue on Mechanical Properties of Painting Canvases

Glues derived from animal products have been used in the preparation and conservation of painting canvas for hundreds of years. However, it is not clear how exactly these adhesives contribute to the mechanical strength of a canvas and how this contribution changes with time. This comparative study looks at the effect of age, thickness, and type of animal glue on the mechanical reinforcement the glues provide to canvas. Isinglass, rabbit skin, bovine hide and bone glue are compared. The mechanical strength of the canvas and glue system have been measured with a tensile test. The influence of glue on the tensile response of canvas has been observed in the slope of the initial region of the stress-strain curve for these samples. This region has been identified as the initial load-bearing region which corresponds to the glue coating. The major contributing factor to change mechanical reinforcement of canvas is found to be the degradation of the glue, however the type of glue used plays a small role as does the thickness of the glue applied.

THE FASTEST COMPUTER RECEIVES THE RESULT FROM THE FUTURE

From school physic class we know that the resistance in the conductors happens as the result of conduction electrons collision with the vibrating molecules’ cores. In order to stop these vibrations it is necessary to protect the conductor from external electromagnetic field. I have discovered that the coverage of pure bone glue of iron conductors reduces their resistance to the electricity till zero. It will allow computers to download the information from the future.

Osteoconstructive nanocomposite based on polyurethane with additives of polysaccharides of various origin

The basics of chemistry and manufacturing techniques of medical bone glue based on a polymer-polyurethane matrix, in which natural polysaccharides are additionally introduced, are described. The physicomechanical characteristics of the reconstructed bones (on the model of pork ribs) are given in comparison with polyurethane without additives (kryptonite). We measured the force necessary for a longitudinal fracture of the bone at the junction, the impact force leading to the destruction of the polymer. The tests were carried out on a universal machine for tensile testing IR 5047-50, the tensile strength of which reaches 50×103 N. It is shown that, compared with the mechanical strength of kryptonite (0.85 kPa), most polysaccharide composites are stronger from 1.2 to 2,3 times. Additives of sodium alginate and hyaluronic acid contribute to the formation of the most stable structures (2.00 MPa and 1.60 MPa, respectively). The strength of the glue with the inclusion of chitin is 1.05 MPa. The least tear resistant is the polyurethane-pectin copolymer (0.140 MPa). The low strength of glue with pectin is explained by the features of its chemical structure, a high degree of esterification of polygalacturonic acid (84%). Impact destruction of the material was recorded at 200 MPa, while the composite crack did not break up into fragments. Thus, the strength of new biopolymer composites is determined by the structure of polysaccharides, which increase the adhesive properties of potential medical adhesives. Using a JSM-6510 LA scanning electron microscope from JEOL (Japan), it was shown that the composite is a cellular structure along the entire depth of the material, 70% of the polymer has pores with a size (55-160) microns. The resulting glue may be compatible with bone tissue. Osteoblasts with a size of 20-30 μm can grow into the cellular structure of new materials and further increase their strength by osseointegration with the host bone. It was found that complete curing of kryptonite occurs in 75 minutes. Materials with additives of other polysaccharides can be cured in much less time (hyaluronic acid, xanthan, pectin in 15 minutes, sodium alginate in 50 minutes. The exception was chitin, which hardens in 200 minutes. During curing, the volume of all polymers increased and amounted to pectin, hyaluronic acid, xanthan gum, sodium alginate, chitin (32; 50; 62; 110, 250)% of the initial value, respectively. Kryptonite was characterized by a 130% increase in volume. Studying the interaction of polymers with water in an isotonic solution of sodium chlorine, imitating the internal environment of the body, showed that kryptonite does not absorb water within 40 days of observation, the mass of pectin increased by 2% in 2 days, xanthan – by 5%, sodium alginate – by 12%, and in 40 days the mass of xanthan gum and sodium alginate increased by 12 and 24%, respectively. The polyurethane composite with pectin lost 10% of its mass in the first 2 days and 35% in the next 40 days, which indicates hydrolysis of ester bonds in polygalacturonic acid. A composite with hyaluronic acid quickly absorbed water (30% in the first 6 hours), turned into a gel and lost its adhesive properties. In air, this polymer hardens quite quickly. It is obvious that composites with hyaluronic acid can only be used in an anhydrous environment. The most promising as medical bone glue is a polyurethane-xanthan copolymer, the physicochemical properties of which (curing time 15 minutes, an increase in volume by 62%) allow the formation of a bone bonding area and also regulate its surface during surgery. There is a direct relationship between the physicochemical properties of the new composites, the features of the primary structure, and the spatial organization of carbohydrate macromolecules. A methodological approach to the development of adhesives promising for reconstructive medicine of mineralized tissues is proposed.