* Ethylene (C2H4): The monomer for polyethylene, a common plastic used for packaging, bottles, and many other products.
* Propylene (C3H6): The monomer for polypropylene, used in a wide range of applications including fibers, containers, and automotive parts.
* Styrene (C8H8): The monomer for polystyrene, used in disposable cups, packaging, and insulation.
* Vinyl chloride (C2H3Cl): The monomer for polyvinyl chloride (PVC), a versatile plastic used in pipes, flooring, and window frames.
These are just a few examples, and there are many other small hydrocarbon molecules that can form polymers.