Polymer chemistry in building plastics: vinyl chloride–vinyl acetate product is obtained by which polymerization route? (Identify the method used to produce VC–VAc copolymer.)

Introduction / Context:
Vinyl plastics employed in building products include homopolymers and copolymers tailored for flexibility, clarity, and processing. A common family is formed by copolymerizing vinyl chloride with vinyl acetate to tune properties versus pure PVC.

Given Data / Assumptions:

• Monomers: vinyl chloride (VC) and vinyl acetate (VAc).
• Goal: modify flexibility, processability, and adhesion relative to neat PVC.
• Reaction type: free-radical chain growth typical of vinyls.

Concept / Approach:
Copolymerization involves simultaneous polymerization of two different monomers into a single macromolecule. VC and VAc undergo addition polymerization by free radicals, but the key classification that captures both monomers together is 'co-polymerization' (a subset of addition processes).

Step-by-Step Solution:

Verification / Alternative check:
Material datasheets list VC–VAc copolymers for adhesives, coatings, and flexible films where acetate segments impart improved flexibility and adhesion.

Why Other Options Are Wrong:

• Addition polymerization: true for each monomer individually, but the question specifically asks for the route to the VC–VAc product, which is copolymerization.
• Condensation polymerization: not the mechanism for vinyl monomers.
• None of these: incorrect since copolymerization is correct.

Common Pitfalls:
Confusing mechanism class (addition) with composition class (copolymer); forgetting that many copolymers are formed by an addition mechanism but are still termed copolymers.

Final Answer:
Co-polymerization (vinyl chloride with vinyl acetate)