What polymer is formed from vinyl chloride and what is a common use?

• A. Polyethylene; used in bottles
• B. Polypropylene; used in cards
• C. Polystyrene; used in packaging
• D. Poly(vinyl chloride) (PVC); used in pipes, cables, window frames

Answer: (D)

Vinyl chloride polymerizes by addition to form poly(vinyl chloride), PVC, with the repeating unit -CH2-CHCl-. The chlorine atom in the backbone gives PVC high chemical resistance and stiffness, so unplasticized PVC is ideal for rigid applications like pipes and window frames, and it also serves as good electrical cable insulation. By adding plasticizers, PVC can become flexible for other uses such as cables. The other polymers in the options come from different monomers (ethylene, propene, styrene) and have different typical applications, but PVC from vinyl chloride is specifically used in pipes, cables, and window frames.