Common applications of polyvinyl alcohol (PVA): select the most typical use from the options provided.
-
ACation/anion exchanger
-
BWater-soluble adhesive
-
CTextile fibre
-
DNon-stick coating for frying pans
Answer
Correct Answer: Water-soluble adhesive
Explanation
Introduction / Context:Polyvinyl alcohol (PVA) is a water-soluble polymer valued for film-forming, adhesion, and emulsifying properties. It is widely used in paper, packaging, and woodworking where water clean-up and low toxicity are desirable.
Given Data / Assumptions:
- PVA dissolves in water; hydrogen bonding enables strong adhesion to polar substrates.
- PVA fibres exist (vinylon), but the most ubiquitous commercial use is as adhesive and binder.
- Non-stick cookware coatings are typically PTFE, not PVA.
Concept / Approach:PVA’s hydroxyl functionality promotes cohesive films and adhesion to paper and wood. Ion-exchange resins usually employ sulfonated polystyrene or similar; PVA is not the standard ion exchanger. Textile fibres from PVA are niche compared with its adhesive dominance.
Step-by-Step Solution:Match property (water solubility, film formation) to use (adhesive).Eliminate ion exchange and PTFE-type cookware coatings.
Verification / Alternative check:Adhesive products (white glues) frequently use PVA or its copolymers (e.g., PVAc emulsions).
Why Other Options Are Wrong:Ion exchange and cookware non-stick require different chemistries; PVA fibre is less common than adhesives.
Common Pitfalls:Confusing PVA with PVAc (polyvinyl acetate); many adhesives are PVAc that may be partially hydrolysed to PVA.
Final Answer:Water-soluble adhesive