A polyolefin's a polymer produced from a simple olefin (also called an alkene with the general formula CnH2n) as a monomer. For example, polyethylene's the polyolefin produced by polymerizing the olefin ethylene. An equivalent term's polyalkene; this's a more modern term, although polyolefin's still used in the petrochemical industry. Polypropylene's another common polyolefin which's made from the olefin propylene. Properties Polyolefins are impossible to join by solvent cementing because they'… (More on Polyolefin)