Guayule natural rubber source

Rubber obtained from botanical sources. The bulk of natural rubber is obtained from the Hevea Brasiliensis free with small amounts from other vines, shrubs and plants mainly the Guayule shrub and the Kok-Saghyz plant. See Isoprene. 

Guayule An Alternative Source of Natural Rubber, National Academy of Sciences, Washington, D.C., 1977. 

National Academy of Sciences (1977). Guayule An Alternative Source of Natural Rubber. Washington, D.C. Jojoba Feasibility for Cultivation on Indian Reservations in the Sonoran Desert Region. Washington, D.C. 

Another unusual plant of the American Southwest and Mexico is the bushlike guayule, which produces a form of natural rubber or latex, as do many other plants, even the dandelion, but not in sufficient quantity. The guayule, however, was employed during WWII when the Malaysian sources of natural rubber were cut off. 

In the original scenario, potential rubber crops were considered. Since then, it was decided to develop guayule (Parthenium argentatum) as a domestic source for natural rubber (1. The U.S. rubber market can potentially be supplied by guayule grown in the southwest. Thus, barring discovery of an... 

J. B. van Beilen and Y. Poirier, Guayule and Russian Dandelion as Alternative Sources of Natural Rubber , Critical Review Biotechnology, 2007, 27, 217-231. 

National Academy of Sciences 1977 Guayule An alternative source of natural rubber. Nat Acad Sci Washington DC... 

Siler, D. X, Cornish, K., Hamilton, R. G. Absence of cross-reactivity of IgE antibodies from subjects allergic to Hevea brasiliensis with new sources of natural rubber latex from guayule (Parthenium argentatum). J. Allergy Clin. Immunol. 1996, 98, 895-902. 

In the United States and in Mexico there has been recent renewed interest in the guayule shrub as a source of natural rubbber. Whilst this shrub could provide an indigenous source of supply to these countries the rubber is more difficult to obtain. At present it is necessary to pull up the bush, macerate it, extract the rubber with solvent and then to preeipitate it from solvent. 

NR belongs to a class of compounds known as elastomers [5]. NR was used for centuries by the Mayans in the Western hemisphere before it was introduced into Europe by Columbus. The term rubber was, however, coined by Joseph Priestly. NR is indispensable in our daily lives. The main uses of NR are concentrated in four key areas, namely medical devices, industrial products, domestic and recreational goods, and foremost automobile products. The current elastomer consumption in the world is 18 million t per year [6]. NR supplies about one-third of the world demand for elastomers. It is also used as an industrial raw material. NR is a naturally occurring elastomeric polymer of isoprene (2-methyl-l,3-butadiene). It can be extracted from latex of only one kind of tree, Hevea braziliensis. Hevea rubber is produced in many tropical regions of Southeast Asia, Africa and Central and South America. There is practically only one other potential source of NR, that is the guayule shrub (Parthenium argentatum). 

Natural r. is derived from the -nubber tree Hevea brasiliensis) and is polyisoprene of high m.w. Another possible source is guayule. The structure was defined by Harries through ->ozonolysis. All other rubbers are petrochemically based. 

---