"**Synthesis of plastics begins with monomers, simple molecules that can be bonded in long chains or branches to make polymers**. The two key monomers, ethylene and propylene, are produced by the steam cracking (heating to 750–950ºC) of hydrocarbon feedstocks, and hydrocarbons also energize subsequent syntheses." ([Location 1719](https://readwise.io/to_kindle?action=open&asin=B08SGC3TD3&location=1719)) --- **Tags** -- [[quotes]], [[chemistry]], [[monomers]], [[polymers]], [[ethylene]], [[propylene]], **Source** -- [[202412030828 - B - How the World Really Works]]