https://www.plasticsmakeitpossible.com/about-plastics/types-of-plastics/what-are-plastics/
The raw materials for today’s plastics come from many places (some even use salt!), but most plastics can be made from the hydrocarbons that are readily available in natural gas, oil and coal.
https://plastics.americanchemistry.com/How-Plastics-Are-Made/
The manufactured or synthetic plastics are often designed to mimic the properties of natural materials. Plastics, also called polymers, are produced by the conversion of natural products or by the synthesis from primary chemicals generally coming from oil, natural gas, or coal.
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The raw material formation may begin by separating the hydrocarbon chemicals from natural gas, petroleum, or coal into pure streams of chemicals.