Soybean adhesives

Casein-soybean adhesives for assembling flush doors in short, room-temperature-curing cycles. 

The final addition of preservative shown in this formulation is essential in virtually all protein glues to provide mold resistance in high-humidity service. Without this protection, even heat-cured soybean adhesives will mold as the moisture content of the bonded wood approaches 20% [24]. Copper-8-quinolinolate, and copper naphthenate are among the few remaining preservatives permitted to be used in the United States at this time for wood products. Where the use of chlorinated phenols or orthophenyl phenol is still permitted, they are also very effective preservatives for protein glues at the addition level shown. In this case, the sodium hydroxide content of the glue formulation converts the water-insoluble chlorinated fungicides to their soluble sodium salts. 

Protein-Based Adhesives. Proteia-based adhesives are aormaHy used as stmctural adhesives they are all polyamino acids that are derived from blood, fish skin, caseia [9000-71 -9] soybeans, or animal hides, bones, and connective tissue (coUagen). Setting or cross-linking methods typically used are iasolubilization by means of hydrated lime and denaturation. Denaturation methods require energy which can come from heat, pressure, or radiation, as well as chemical denaturants such as carbon disulfide [75-15-0] or thiourea [62-56-6]. Complexiag salts such as those based upon cobalt, copper, or chromium have also been used. Formaldehyde and formaldehyde donors such as h exam ethyl en etetra am in e can be used to form cross-links. Removal of water from a proteia will also often denature the material. 

In the late 1800s, when the demand for coated paper for the halftone printing process increased, casein rapidly replaced glue. Casein forms a hard, tough film when dry, and can be waterproofed easily with formaldehyde (qv). The properties of soy protein are similar to those of casein, and soy protein has been substituted for it in many types of coated papers requiring a casein-type binder (see Soybeans and other oilseeds). Casein, a valuable food product, is seldom used as a paper adhesive, in spite of its excellent adhesive properties. 

Affordable Resins and Adhesives from Optimized Soybean Varieties, U.S. Department of Energy, Industrial Technologies Program Fact Sheet, May 2002. 

Figure 13. SEM of Bacos spun soybean protein fiber simulated meat product. Egg albumin used as adhesive for fibers (33).

Epoxidized oils such as soybean oil or linseed oil, which are made by oxidizing the internal unsaturation in the fatty acid chain, find much use as plasticizers, particularly in vinyl resins. An internal epoxy ring is much less reactive than a terminal epoxy ring and usually does not take part in typical epoxy curing reactions under mild conditions. These materials can be used as plasticizers in epoxy adhesives but cannot really be considered reactive diluents. 

Often, foods must be treated as engineering materials. Heat has to be transported so that the components become cooked or harmful microorganisms and toxins become inactivated. Even in the kitchen, mixing involves the mass transfer of liquids and solids to form metastable structures, which are fixed by subsequent treatment by heat or cooling. Heat transfer properties are crucial in the formation of ice crystals in ice cream and fat crystals in chocolate products. Food materials have been used as a source of industrial components soybean proteins to manufacture auto parts in the 1940s, casein to make buttons and knitting pins, and starches in adhesives and thickeners. 

Industrial applications of proteins include plastics, adhesives, and fibers derived from casein and soybean protein, but these have been declining in recent years. Special forms in which proteins are commercially available include textured proteins for food products, and protein hydrolyzate and liquid predigested protein, both for medical use. See ribonu-... 

A wood-based composite can be defined as a composite material mainly composed of wood elements. These wood elements are usually bonded together by a thermosetting adhesive (wood truss products could also be regarded as wood-based composites, but connected by metal connectors). The commonly used adhesives include urea-based adhesive (such as urea formaldehyde resin), phenolic-based adhesive (including phenol resorcinol adhesives), isocyanate-based adhesive, and adhesives from renewable resources (like soybean, lignin etc). The wood elements in wood composites can be in many different forms such as ... 

Among the commercial bioproducts are biomaterials, fuels and chemicals. Some of the most common biomaterials include soybean oils, inks, pigments and dyes, paints and varnishes, soaps and detergents, industrial adhesives, biopolymers and films, and composite materials. 

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