NATURAL RUBBER FROM DOMESTIC CROPS

The United States is wholly dependent upon imports of natural rubber from tropical countries and is the world’s largest consumer of this strategic raw material.  Development of domestic rubber crops can create supply security for this strategic raw material, enhance rural development and create biobased replacements for petroleum-based polymers. These new industrial crops must deliver high quality natural rubber to the market in an economically and environmentally sustainable manner.  Our study compares rubber from various candidate crops to provide a baseline for development strategies. We report the physical and chemical properties of rubber from alternative species, and from H. brasiliensis and synthetic polyisoprene. New rubber crops like guayule and Russian dandelion produce polymers of the same stereochemistry and similar molecular weight to that of Hevea. However, rubber particles isolated from different plants show species-specific traits in their non-rubber constituents. The difference between rubbers produced by different species may be primarily due to these non-rubber constituents with important consequences for industrial use.