Submitted to: Association for the Advancement of Industrial Crops Conference
Publication Type: Abstract only
Publication Acceptance Date: 10/10/2003
Publication Date: 10/15/2003
Citation: NAKAYAMA, F.S. GUAYULE FUTURE DEVELOPMENT. ASSOCIATION FOR THE ADVANCEMENT OF INDUSTRIAL CROPS CONFERENCE. 2003. Interpretive Summary:
Technical Abstract: Successful commercial development of guayule (Parthenium argentatum Gray) will depend on using as much of the plant as possible. At present, latex is the plant's primary product. Utilizatiion of the remaining components that include resin and biomass can greatly improve the economics of guayule. The purpose of this presentation is to review new and possible alternate products that can be made from guayule "waste" material that can enhance the commercialization of guayule. Coproduct development can augment the commercialization of natural, renewable resources. For guayule, about 90% of the plant material to be grown in several hundred thousand hectares would be available for coproduct development. Fortunately, guayule synthesizes many potentially useful compounds for industrial and commercial applications. These include fatty acid triglycerides, flavonoids, polyphenols, terpenes, sesquiterpenes, and waxes that make up about 10% of the whole plant. Also, we cannot neglect the other 80% of the cellulosic material. The resinous material is of special interest because of its antitermitic and wood-rot resistance properties. Because of the water-based process used to extract latex, the residual plant material or bagasse will still contain the resin. This resin-containing bagasse without additional chemical processing has been fabricated into high-density, construction-grade, composite boards that are resistant to attack by termite and wood-rot fungi. In the future, bagasse could be blended with many other wood sources with different densities and physical properties that have insect control properties. The bagasse or the resinous extract could be incorporated into wood putty or caulking, for example, to make sure repair material insect resistant. The resin extracted from the latex-processed bagasse with a polar organic solvent can be used without purification. Such resins when impregnated into wood can provide protection against other wood destroying organisms such as marine borers. Possibly, this resin extract can be used to protect wood and trees against wood attacking insects such as carpenter ant and bark beetle. In addition, the resin can be used in paint primers and varnishes with similar insect control properties. The resin has been incorporated with epoxy polymers to produce coatings that are readily strippable, a useful property for storge-protection of aircrafts, ships, and other industrial equipment undergoing environmental exposure. Other potential ues for the bagasse or resin is in the area of energy production. The bagasse can be formed into fire logs, briquettes, and pellets. Such combustile material has higher energy value than other wood sources because of the resin, which can make up about 10% of the dry mass. The bagasse has been converted into gaseous and liquid fuel, and with improved pyrolysis into a soure of alcohol and other type of chemicl entities for liquid fuel or solvents. Ongoing attempts to increase the rubber content and biomass of the plant have increased the resin to rubber ratio to 2:1 from that of 1:1. Although unintentional, this crop improving development may be fortuitous because the resin fraction appears to be just as valuable as the latex component. The Parthenium genus consists of numerous species that can grow faster than guayule with larger biomass, but consists mostly of resinous material instead of rubber. The future commercial development of these other Parthenium genus also appears promising.