Latex extracted directly from a tree is thirty to forty percent rubber. Up to fifteen percent of that rubber is soil. The amount of soil in the rubber determines its grade.
SMR has a minute amount of ash. Interestingly, recycled tire ash from used and shredded tires is highly toxic. This type of ash leads to permanent, irreversible soil damage.
Nitrogen is a hardening property of rubber. The concentration of nitrogen determines how flexible the product will be. The more nitrogen in the rubber, the harder it becomes.
Acetone, which is a corrosive, dissolves rubber. However, balanced correctly with nitrogen, aceteone gives rubber its flexibility and stiffness.
Trace amounts of copper are created when rubber is bonded to brass. The zinc oxide reacts with copper oxide found on copper's surface. The result is zinc-copper salt, which forms a tight bond between the two substances.
SMR contains trace amounts of manganese salts. The amount of manganese salts determines how long the rubber will last. The more manganese salt, the lower the quality of the rubber.