Which statement about nylon's behavior with moisture is accurate?

• A. Nylon dissolves in water
• B. Nylon loses strength when wet but regains it when dry
• C. Nylon is unaffected by moisture
• D. Nylon gains strength when wet and loses when dry

Answer: (B)

Nylon is a hygroscopic polymer, meaning it readily absorbs moisture from the surrounding environment. When water is absorbed, it acts as a plasticizer: it gets between the polymer chains, increasing their mobility and weakening the intermolecular forces that hold the structure together. This makes the material softer and weaker in tension when it’s wet. When you dry it, the water leaves, the chains’ interactions rebound, and the strength returns toward the dry-state value. So the accurate statement reflects this reversible, moisture-induced weakening: nylon loses strength when wet but regains it when dry. The other ideas aren’t correct because nylon isn’t soluble in water, moisture does affect its properties, and moisture doesn’t generally increase strength.