Which statement best describes condensation polymerisation?

Which statement best describes condensation polymerisation?

• A. It forms polymers with loss of a small molecule such as water; examples include polyesters.
• B. It forms polymers with no by-products; example polyethylene.
• C. It only forms polymers from monomers that contain double bonds.
• D. It is the same as addition polymerisation.

Answer: (A)

Condensation polymerisation occurs when monomers with two reactive groups join together and a small molecule is released each time a bond forms, commonly water. This release of a by-product is what gives polymers like polyesters their characteristic structure, since the linking steps create ester bonds while water is expelled. This is different from addition polymerisation, which links unsaturated monomers such as alkenes without producing any small molecular by-products; polyethylene is made this way, so it doesn’t fit condensation polymerisation. The description about forming polymers with no by-products and about double bonds in all monomers aren’t accurate for condensation polymerisation, so the statement that best describes it is the one that highlights loss of a small molecule (often water) during polymer formation, with polyesters as a classic example.

Condensation polymerisation occurs when monomers with two reactive groups join together and a small molecule is released each time a bond forms, commonly water. This release of a by-product is what gives polymers like polyesters their characteristic structure, since the linking steps create ester bonds while water is expelled. This is different from addition polymerisation, which links unsaturated monomers such as alkenes without producing any small molecular by-products; polyethylene is made this way, so it doesn’t fit condensation polymerisation. The description about forming polymers with no by-products and about double bonds in all monomers aren’t accurate for condensation polymerisation, so the statement that best describes it is the one that highlights loss of a small molecule (often water) during polymer formation, with polyesters as a classic example.