Answer: Increases rigidity and reduces solubility.
- A Increases rigidity and reduces solubility
- B Decreases the melting point by disrupting chain packing
- C Increases flexibility by allowing chains to slide past each other
- D Increases solubility by exposing more polar groups to solvent
Correct answer: A. Increases rigidity and reduces solubility
Explanation: Cross-links (covalent bonds between chains) prevent chain movement, increasing hardness, rigidity, and reducing solubility.
Addition polymerisation simply links monomers containing a double bond with nothing left over, while condensation polymerisation joins two different monomers through a reaction (often forming an ester or amide bond) that releases a small molecule like water at each step.
Concept context
Large molecules made of repeating monomer units. Covers addition and condensation polymerisation, natural and synthetic polymers (nylon, PVC, Bakelite, natural rubber), and their real-world industrial applications.