Trefoil rubber (made in Brazil, also known as Brazilian rubber) is the most familiar natural rubber in the rubber industry. In fact, natural rubber with the same composition and similar properties in nature is not the only one, but for various reasons, some natural rubber species do not form scale production, and there are many species with unique properties and specific use value. The following two are well received.
The growth of the mother chrysanthemum of the gerbera rubber includes grasslands or sand belts in Mexico, South America and Russia. Silver chrysanthemum is a shrub plant whose main components of the gum secreted by the trunk, roots and bark are rubber bismuth (cis-1,4-polyisoprene), which is the same as the trilobite. Contains ingredients such as aromas and resins. Silver chrysanthemum is suitable for growth in temperate and subtropical natural environments and can survive in dry and water-deficient conditions. In view of the low gel yield (only 15% to 17%), although the cultivation requirements are not as harsh as those of the trefoil, as a cash crop, there is still insufficient attraction. The composition of the zeocary gum includes 70% of rubber hydrocarbons, 20% of resin, and 10% of lignin.
The molecular structure of the rubber hydrocarbon is the same as that of the trilobite, ie, cis-1,4 polyisoprene, but the average molecular weight is relatively low, the molecular weight distribution is narrow, the vulcanization rate is slower than that of the trilobite, and the physical properties are basically equivalent. The collection method of gerbera gum is also different from the trilobite. Instead of adopting the tapping method, the root leaves are harvested and placed on a grooved rolling machine to be rolled into pieces.
During the Second World War, Southeast Asia fell into the hands of Japan because of the origin of Sanye natural rubber. The development and production of synthetic rubber took time and could not save the urgent need. At that time, the United States once vigorously developed silvery rubber to make up for it. Raw rubber gap. According to the tire comparison test made at that time, the tires with silvery gum as raw materials have a mileage life of 61,000km, which exceeds the tires with the gums (55000km).
In the Vietnam War, the United States repeated itself and focused on cultivating silver chrysanthemums in states close to the Mexican border as a strategic backup measure.