Thermoplastics are made of long chains of molecules called polymers. These polymers are formed by joining together many smaller molecules called monomers.

Here's a breakdown:

* Monomers: The building blocks of polymers. They are small, simple molecules. Examples include ethylene, propylene, vinyl chloride, and styrene.

* Polymers: Long chains of monomers linked together. They have large molecular weights and can be either natural (like cellulose) or synthetic (like polyethylene).

* Thermoplastics: Polymers that can be repeatedly softened by heating and hardened by cooling. They are usually made of synthetic polymers like:

* Polyethylene (PE): Used in plastic bags, bottles, and films.

* Polypropylene (PP): Used in packaging, containers, and fibers.

* Polyvinyl chloride (PVC): Used in pipes, windows, and flooring.

* Polyethylene terephthalate (PET): Used in bottles, clothing, and fibers.

* Polystyrene (PS): Used in cups, containers, and insulation.

* Polycarbonate (PC): Used in CDs, lenses, and safety glasses.

The specific monomers used to create a particular thermoplastic determine its properties, such as its strength, flexibility, melting point, and chemical resistance.

Let me know if you'd like more detail on any specific thermoplastic!