Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: April 24, 2009
Publication Date: September 12, 2009
Citation: Mcmahan, C.M. 2009. Natural Rubber from Domestic Crops. American Chemical Society (ACS) Rubber Division Meeting, Pittsburgh, PA, October 12-16, 2009. Interpretive Summary: Domestic natural rubber from agricultural sources will provide supply security for this critical raw material and reduce dependency on petroleum-based rubber in an environmentally and economically sustainable manner. Domestic rubber-producing guayule has been recently re-introduced in the U.S., but commercial acceptance been limited by lack of demonstrated technological equivalence to Hevea rubber in tire applications. The sustainability of any domestic rubber source requires engineered performance equal to or better than petroleum-based synthetics. Our hypothesis is that the unique properties of Hevea natural rubber are due to highly expressed proteins and/or lipids, manifest through nanostructural features of the polymer-protein complex. Our objectives are to identify these specific constituents and to quantify their impact on the structure and properties of rubber. That knowledge will then be applied to chemical and molecular engineering of domestically-produced biobased rubber.
Technical Abstract: 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 will create supply security for this strategic raw material, enhance rural development, and create biobased replacement 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 natural rubber from alternative crops, and from Hevea 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. Natural rubbers produced by different species differ primarily by their non-rubber constituents with important consequences for industrial use.