PVC is typically described as which of the following?

• A. Strong and hard, less flexible than polythene
• B. Soft and stretchy
• C. A gas at room temperature
• D. Highly flammable and liquid

Answer: (A)

Think about how the structure of a polymer affects its stiffness. PVC is polyvinyl chloride, and the chlorine atoms attached to the carbon backbone make the chains bulky and the intermolecular forces stronger. That means the chains don’t slide past each other easily, so rigid PVC is strong and hard and shows little flexibility. In contrast, polythene has a simpler hydrocarbon backbone with fewer bulky groups, so the chains can move more freely and the material is more flexible.

PVC is a solid at room temperature, which is why it’s used for hard items like pipes and window frames. It isn’t a gas or a liquid under ordinary conditions. While PVC can be made softer with plasticizers, the default description of PVC in its rigid form is that it is strong and hard and less flexible than polythene.