Abstract
Natural rubber is an irreplaceable raw material vital to industry, transportation, medicine and defense, largely produced from clonal plantations of Hevea brasiliensis in Southeast Asia. Additional rubber-producing crops are greatly desired to increase biodiversity, protect supplies, and provide a safe alternative for people suffering from Type I latex protein allergy. Basic and applied research approaches were used to make the production of latex (Yulex® latex) from Parthenium argentatum (guayule) a commercial reality. In contrast to Hevea brasiliensis, from which rubber latex is tapped by hand from laticifers, guayule latex rubber is contained within individual bark parenchyma cells. Processing involves disrupting these cells to release the rubber particles, and then purifying the latex. As in the Hevea industry, latex concentration can be achieved by centrifugation and/or by creaming agents. An artificially produced guayule natural rubber latex is then produced, under the material name of “Yulex® latex”. The Yulex Pilot Plant has been constructed, optimized and automated, and extracts then purifies latex from guayule shrub without detectable losses. The natural rubber polymers in guayule latex are high molecular weight and products made from this material have the desired high performance properties. Because guayule latex contains very little protein, all of which is hydrophobic and bound to the rubber phase, and because none of the protein cross-reacts with Type I latex allergy to Hevea latex products, its use is initially aimed towards the high-value medical products marketplace. Clinical and performance trials continue to ensure that guayule processing provides a safe, high performance, non-allergenic natural rubber latex that is safe for human use.
Reinforcing biofiller “Lignin” for high performance green natural rubber nanocomposites
