Which polymer is typically stronger than polythene but still tough and durable?

Which polymer is typically stronger than polythene but still tough and durable?

• A. Polypropene
• B. PVC
• C. Polystyrene
• D. Polycarbonate

Answer: (A)

The key idea here is how the structure of a polymer affects its strength and toughness. Polythene is fairly flexible, with chains that can slide past each other, so it’s not very strong. Polypropene has methyl groups along the chain, which hinder chain sliding and make the material stiffer and stronger. This combination gives higher strength than polythene while still being capable of absorbing impact, so it’s tough and durable. Other options don’t fit as well because they’re either more brittle or require conditions beyond basic properties: polystyrene is hard but very brittle; PVC is strong and rigid but can be brittle rather than tough; polycarbonate is extremely tough but is typically discussed in a different context and isn’t the standard comparison for “stronger than polythene but still tough.”

The key idea here is how the structure of a polymer affects its strength and toughness. Polythene is fairly flexible, with chains that can slide past each other, so it’s not very strong. Polypropene has methyl groups along the chain, which hinder chain sliding and make the material stiffer and stronger. This combination gives higher strength than polythene while still being capable of absorbing impact, so it’s tough and durable.

Other options don’t fit as well because they’re either more brittle or require conditions beyond basic properties: polystyrene is hard but very brittle; PVC is strong and rigid but can be brittle rather than tough; polycarbonate is extremely tough but is typically discussed in a different context and isn’t the standard comparison for “stronger than polythene but still tough.”