What is the composition of oligomers?

• A. Solid only
• B. Gas
• C. Between solid and liquid
• D. Liquid only

Answer: (C)

Oligomers are short-chain molecules whose properties fall between those of monomers and long polymers. Because they consist of only a few repeating units, they have more structure and intermolecular interactions than monomers but not enough to behave like full polymers. This gives them a physical state that isn’t a hard solid or a simple liquid, but something in between—often a viscous liquid or semi-solid. Gas is unlikely for oligomers because their larger size and stronger intermolecular forces make them far less volatile. Some oligomers can be solids, but many exist as liquids or semi-solids at room temperature, so the best description is that their composition sits between solid and liquid.