Rubber industry analysts have estimated by 2020 that the global demand for natural rubber will exceed supplies by over 20 percent. Biotechnology firms have been developing techniques to extract latex from different plants such as guayule and dandelions.
There is little danger that the world will run out of natural rubber although its supply can be quite unpredictable. Most of the world's rubber is grown in South and Southeast Asia where extreme weather conditions and natural disasters can have a dramatic effect on production. Flooding from earthquake-induced tsunamis, as well as the weather, has badly damaged production. Older rubber trees that were planted during the 1980s will also have to be uprooted and replaced with new plants, so reducing the area of worldwide plantations. New rubber plantations are being established in West Africa but these may not keep up with rising world rubber demand, especially in automobile tyres and gloves. Rubber has also become a major traded commodity over the past decade. In common with petroleum and refined products, market speculation has driven up prices.
Many Plant Species Produce Latex
This combination of factors has led rubber manufacturers to seek alternative supplies of natural latex. There are over 2,000 plant species in the world that can produce latex but the Hevea tree, native to tropical climates in South America that was later exported to Southeast Asia, is the most dominant. Now the idea is to use some of the plants that were used to produce latex between the 1920s and 1940s when supplies from Southeast Asia and South America were cut.
Guayule is a plant native to the south-western United States and Mexico. It thrives in Arizona's arid climate. When leaf blight destroyed the then thriving Brazilian rubber industry and Japan occupied Southeast Asian rubber plantations during World War 2, American companies began to develop latex from the Guayule plant. The effort was abandoned following the return of secure rubber supplies from Southeast Asia. Now the idea is to use Guayule as a replacement not only for natural rubber but also for synthetic rubber derived from petroleum products. Guayule produces the same polymer as Hevea latex but it first has to be domesticated as a crop and then grown in commercial quantities.
Milky sap in dandelion roots contains a substance similar to Hevea latex, but the common meadow dandelion of North Western Europe does not contain enough latex for commercial production. However, a dandelion species native to Central Russia, Kazakhstan and Uzbekistan may be able to produce commercial quantities of latex. This plant was developed for rubber production in the 1940s when Southeast Asian rubber supplies were unavailable. However, the latex extraction process in those days involved chemicals that today are regarded as environmentally damaging. The challenge is to find a mechanical means of latex extraction.
Plant products are already used in some plastics and synthetic rubbers. Soya bean oil is used as a plasticiser for PVC and oil from orange peels is incorporated into passenger car tyres to replace petroleum products. The aim now is to develop an entirely plant-based synthetic rubber that may substitute for petroleum derived synthetics and ensure supplies to rubber manufacturers.