Parthenium argentatum Natural rubber

The chlorination of low molecular weight natural rubber from Guayule (Parthenium Argentatum Grey) has been accomplished. The structure of the chlorinated product is consistent with that of chlorinated Hevea rubber. The use of Azo-bis-isobutyronitrile was as a catalyst resulted in increased chlorine content with a concomitant reduction in molecular weight, thereby allowing the preparation of lower viscosity grades of chlorinated rubber. 

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). 

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... 

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. 

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