There are a number of different uses for urea, but it is perhaps most commonly found in plant and crop fertilizers; it also features as an ingredient in many different resins and plastics, and is sometimes added to cosmetics and consumer products like cigarettes and even gasoline. The compound is usually made from concentrated mammal urine. The chemical process through which it is extracted renders it completely sterile, and in most cases it has a crystalline structure that looks something like rough salt. It has a number of smoothing and adhesive properties that manufacturers of all sorts of products find valuable, and it is prized particularly for its high nitrogen content. Adding it to livestock feed can be an economical way to add nutrients animals might not otherwise get.
History and Basics of Use
Urea was first observed by the French chemist Hilaire Rouele. It is a very important part of the metabolic system in humans and most animals, and its primary function in these settings is as a carrier of waste nitrogen. German chemist Friedrich Wohler was the first to create it synthetically, thereby proving that an organic compound can be produced from non-organic materials. Today, synthetic urea is made from ammonia and carbon dioxide in which ammonium carbamate is dehydrated under conditions of high heat and pressure.
The most common application of urea is as a type of fertilizer. Over 90% of the world's production of the substance is done for fertilizer-related products. When used in this way, it usually takes the form of granules or crystals. These may be manually distributed by farmers or scattered with the aid of farming equipment. It is also often used in fertilizing solutions, since it is highly water soluble, and often comes packed within soil and potting mixes.
Resins and Plastics
This compound is also frequently used as a base product in the manufacture of resins and commercial adhesives. The nitrogen bonds that it contains tend to be very strong, and can really help strengthen a number of glues and tapes. Manufacturers often activate these bonds by dissolving the crystals in formaldehyde. The resulting mixture can be used as an industrial adhesive, as in the production of cardboard boxes; it also features as an ingredient in many poured plastics. In some cases it could also be used as a coating for materials like textiles and paper.
A number of consumer-oriented and cosmetics products also incorporate this substance. Hair conditioners or tooth-whitening products often use it, for instance, usually as a way to help the product stay thick in the tube or bottle. Dish soaps sometimes also include it in at least in trace amounts to help keep emulsified ingredients from separating.
Facial cleaners sometimes incorporate the substance, too, since it can help in hydrating the skin. Certain makeup products blend it in to help achieve a creamier, glossier finish once applied. Environmental activists in many places are often quick to point out that it can be used in an eco-friendly way to reduce fuel emissions from power plants and diesel engines, too.
Urea is sometimes also used in cattle and livestock feed, particularly in the developing world. It is usually considered to be an effective feed since it contains high concentrations of nitrogen, which can generally aid animal growth. The compound is relatively inexpensive to make and doesn’t cost much to transport, two factors that boost its popularity in many parts of the world.