35.2.2—The type of polymerisation reaction
- Syllabus
- 9701–2028–2029
- Objective
- 35.2.2
- Level
- A2
Recognise polymerisation type from the link and by-product
A polymer section made by addition retains the carbon backbone from opened C=C bonds and has no alternating small-molecule loss. A condensation section contains ester or amide links formed with elimination of water or HCl.
Work backwards: locate the repeating linkage, restore monomer functional groups, and ask whether a small molecule must have been removed.
A chain with –CH₂–CH₂– repeats comes from addition of ethene; a chain with –CO–NH– links is a condensation polyamide.
Do not classify from the polymer name alone; the repeat structure is the evidence.
ConceptA-Level CAIE Chemistry A2