Name the polymerisation process in which two or more chemically different monomers participate together to form a macromolecule.

Introduction / Context:
Copolymers allow tuning of mechanical, thermal, and chemical properties by incorporating more than one monomer into the polymer chain. This is central to modern materials design (e.g., SBR, ABS, EVA).

Given Data / Assumptions:

• We require the term for multi-monomer polymerisation.
• Other terms (addition, chain) describe mechanism, not monomer variety.

Concept / Approach:
Copolymerisation refers specifically to polymer formation from two or more distinct monomer species, regardless of whether the underlying mechanism is chain-growth or step-growth.

Step-by-Step Solution:
Match definition to term: copolymerisation.Exclude mechanism-oriented alternatives.

Verification / Alternative check:
Examples include SBR (styrene + butadiene), EVA (ethylene + vinyl acetate), and ABS (acrylonitrile + butadiene + styrene).

Why Other Options Are Wrong:
Addition and chain polymerisation address kinetics/mechanism, not monomer diversity.

Common Pitfalls:
Conflating copolymerisation with polymer blends; blends are physical mixtures, not chemical copolymers.

Final Answer:
Copolymerisation