Monday, April 8, 2019

Investigating Glue Essay Example for Free

Investigating Glue EssayTitleTo recycle the bad protein sustenance by reproducing attachAimHave you even thrown some food because it becomes bad? Do you think it really waste money? Do you want to exploit them become useful once much? If you do, our experiment will intend you how to do and everything about it.ApparatusHeater, measuring cylinder 2(250ml50ml),pH report,beaker2(300ml500ml),glass rod, take awayChemicalskim draw, vinegarAbstractThe cohesive properties of different proteins in daily food be being investigated in our experiment. Casein in dairy products and textured soja bean protein (TSP) in soybean products argon abstracted out by precipitation in acid. The samples are then neutralized by carbonate and undergo a series of stress tests to compare the strength of our reproduced protein gumwoods with commercial products.The basic principle of the druming properties of protein mucilages is the ionic attractions and the Van der Walls attractive force generat ed by the protein molecules. Protein molecules are highly folded, resulting in a cracking contact surface area and exposure of the hydrophobic bonds. When two surfaces of substances like wood or typography are held together by protein, linkages are formed in between the molecules, and the two surfaces are stick together and are difficult to separate.We expect the result the casein paint in milk and textured soy protein in soybean milk have comparable sticking strength as starch contained in commercial chewing gum. The signifi weedt advantage of the production of our protein gums is that proteins in expired food can be recycled and reuse to make the useful attach. The glue produced is also not toxic or harmful to the environment.Introduction1)The history of glueThe earliest evidence of use of glue can still be observed in the hollow paintings made by Neanderthal ancestors in Lascaux, France. These early artists wanted their work to last and mixed glue with the paint they utili se to help the colors resist the moisture of the cave walls. Egyptian artifacts unearthed in their tombs show galore(postnominal) uses of glues perhaps the approximately striking are the veneers and inlays in wood furniture, which was made using glue as early as 3,000 B.C. The Egyptians also used glue to produce papyrus. Greek and Roman artists used glues extensively mosaic floors and tiled walls and baths are still intact after thousands of years.Around 1750, the first glue or adhesive patent was issued in Britain. The glue was made from fish. Patents were then rapidly issued for adhesives using lifelike rubber, animal bones, fish, starch, milk protein or casein. As we can see from ancient and medieval records, fish glue was both a common and important adhesive for many special applications adapted by artists, it was used from the time of ancient Egypt to twentieth-century France, in painting media, coatings and grounds, in the gilding of illuminated manuscripts, and in pastel f ixatives.2)Theory of milk glueCasein is the principal protein found in cow milk (about 3%) from which it has been extracted commercially for most of the 20th century. It is responsible for the white, opaque appearance of milk in which it is combined with calcium and phosphorus as clusters of casein molecules, called micelles.The major uses of casein until the 1960s were in technical, non-food applications such as adhesives for wood, in paper coating, lash finishing and in synthetic fibers, as well as plastics for buttons, buckles etc.The first step in making acid-precipitated casein is acidification. Mineral acids or organic acids can add to the skim milk or the milk is allowed to sour, in which case lactic acid, produced by fermentation of lactose, is the effective precipitant. The precipitated curd is then drained, washed, press to have peeing, milled, drill, and ground. Solutions of casein in alkalis (with enough of the protein to give a suitable viscosity) can be used as glue .Such glue compares favorably in strength with animal glue on drying the protein forms numerous total heat bonds with the cellulose in paper and with itself, so it can stick woods together, but it is not water-resistant. Resistance to water can be imparted to casein glue, however, by modifying the simple formula of casein in alkali these meliorate casein glues are widely useful in industry. Prepared casein glues are sold in the form of dry salmagundis, which need only the addition of water before use.They are commonly undisturbed of casein, lime, and a number of alkaline salts. Various chemicals have been used to improve the resistance to water, and many colloidal materials with adhesive properties can be mixed with casein to modify the properties of the resulting glues. It has thus been possible to adapt casein glues to a variety of specialized applications. These glues are used in the woodworking industry, in gluing paper, and in many other fields.ProcedurePreparation of milk glue1) 250cm3 of milk and 50cm3 of vinegar (about 5% ethanoic acid) were added into a beaker.2) The mixture was heated slowly and stirred continuously until curds were observed. (Caution Heater is very hot, temperature of mixture should not be more than 60C)3) Curds were allowed to settle to the bottom for about 10 minutes.4) The heated mixture was filtered.5) The curds were squeezed to remove liquid.6) The curds were washed with teeny volume of water and squeezed again.7) The curds were stirred with solid sodium hydrogencarbonate (NaHCO3) gradually and monitored pH by pH paper until pH became slightly alkali.Testing of adhere strength of glue1) The glues were used to stick two plyboard together, a the plywood at downside , with contact surface of 20 cm22) Two samples were made for each glue and one sample of starch glue was made as control.3) The stack plywood was pressed by 0.8kg mass and allowed to dry at dry place for 2 days .4) The plywood was set supra the ground.5) 0.5 kg T est mass was added gently each time until the masses drop.6) The maximum mass of the glues that can afforded were recorded.7) The plywood was cut into 4, which contact surface was decreased 4 times, and the above tests were repeated.Reference1)http//classes.ansci.illinois.edu/ansc438/milkcompsynth/milkcomp_protein.html2)http//science-in-farming.library4farming.org/Crops-Grains-Protein/PROTEINS-ARE-BASIC/Milk-Proteins.html

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