Vinyl chloride–vinyl acetate copolymer: the resulting material is generally described mechanically as which type of polymer?

Introduction / Context:
Copolymers of vinyl chloride with vinyl acetate modify the properties of PVC, improving flexibility and impact behaviour compared with rigid homopolymer PVC. The question asks for the general qualitative description used for such a copolymer.

Given Data / Assumptions:

• Vinyl acetate comonomer disrupts PVC crystallinity and lowers glass transition temperature.
• Resulting material becomes tougher and more flexible than rigid PVC.
• Terminology is qualitative, reflecting feel and flexibility relative to rigid plastics and elastomers.

Concept / Approach:
With sufficient vinyl acetate, the PVC matrix softens and exhibits a pliable, flexible feel described in classical exam terminology as “leathery” — softer than rigid plastics but not fully rubbery/elastomeric without plasticiser levels typical of rubbers. “Fibrous” is inappropriate (that refers to materials drawn into fibres), and “hard” matches unmodified, rigid PVC rather than the copolymerised product.

Step-by-Step Solution:
Relate comonomer effect (VAC) to flexibility and toughness.Map qualitative categories: rigid < leathery < rubbery.Select “Leathery” to describe VC–VAC copolymer behaviour.

Verification / Alternative check:
Materials references describe VC–VAC copolymers and plasticised PVC products as leathery/semiflexible depending on formulation.

Why Other Options Are Wrong:
Fibrous: relates to drawability, not bulk mechanical feel.Rubbery: requires higher elasticity than typical VC–VAC without heavy plasticisation.Hard: closer to rigid PVC than to the copolymer’s softened state.

Common Pitfalls:
Assuming all VC-based materials are rigid; copolymerisation and plasticisers change mechanical character substantially.

Final Answer:
Leathery