There are two types of rubber, synthetic and natural, which are made using different processes. Natural rubber is made from the sap of the rubber tree, which is extracted from the tree and then mixed with sulfur and white lead and heated in a process known as vulcanization.
Until the 1800s, the sap from rubber trees, known as latex, was simply allowed to dry to form a basic rubber. However, this type of rubber is susceptible to heat and cold, which is why vulcanization is needed to make it more stable in all temperatures.
Synthetic rubber can be made in a number of different ways, but virtually every way involves using some form of gas that results from the petroleum refining process. Crude oil is one of the primary ingredients in almost all types of synthetic rubber, as the majority tend to be based on carbon polymers. However, the one exception is silicone rubber, which is made using silicon-based polymers instead of carbon.
Another common type of synthetic rubber is latex, which is different from the latex sap that comes from rubber trees. The type of latex used to make rubber gloves is another petroleum-based product, which is made by taking a basic carbon polymer and vulcanizing it over lower temperatures after adding specific polysulfides to it.