Identify the polyolefin among the following polymers (choose the single correct polyolefin).
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APolystyrene
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BPolypropylene
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CNeoprene (polychloroprene)
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DNone of these
Answer
Correct Answer: Polypropylene
Explanation
Introduction / Context:Polyolefins are polymers made from simple olefin monomers such as ethylene and propylene. They are ubiquitous due to low cost, chemical resistance, and versatile processing. Distinguishing a polyolefin from other vinyl or diene polymers is a foundational classification task.
Given Data / Assumptions:
- Polypropylene (PP) is produced from propylene, a simple olefin → polyolefin.
- Polystyrene derives from styrene (vinyl aromatic), typically not classed as a polyolefin.
- Neoprene (polychloroprene) is a chlorinated diene elastomer, not a polyolefin.
Concept / Approach:Polyolefins are saturated hydrocarbon backbones from alpha-olefin monomers (e.g., PE from ethylene, PP from propylene). Polystyrene contains a pendant phenyl group and distinct properties; it is categorised as a vinyl polymer, not a polyolefin. Neoprene contains chlorine and double-bond-derived structure, hence is an elastomer outside the polyolefin family.
Step-by-Step Solution:Identify olefin-based polymer → polypropylene.Eliminate polystyrene (vinyl aromatic) and neoprene (chloroprene rubber).Select polypropylene as the sole polyolefin listed.
Verification / Alternative check:Commodity polymer classifications list PE and PP as the principal polyolefins.
Why Other Options Are Wrong:Polystyrene: not a polyolefin; different monomer family and properties.Neoprene: synthetic rubber; chlorinated diene polymer.None of these: incorrect because PP is indeed a polyolefin.
Common Pitfalls:Generalising “vinyl polymers” and “polyolefins” as the same; they are overlapping but not identical categories.
Final Answer:Polypropylene