Difficulty: Easy
Correct Answer: All of these
Explanation:
Introduction / Context:
Plastics used in building services, packaging, and consumer goods are formed by different polymerization routes. Distinguishing addition (chain-growth) from condensation (step-growth) polymerization helps predict properties, processing, and recycling behavior. This question asks which common plastics are produced via the addition mechanism.
Given Data / Assumptions:
Concept / Approach:
Polyethylene, polypropylene, polyvinyl chloride, and polystyrene are all produced by addition polymerization. In each case, double-bond-containing monomers (or vinyl monomers) undergo initiation, propagation, and termination to form long chains. No small by-product (like water or HCl from the reaction itself) is eliminated during chain growth; PVC contains chlorine in the monomer structure but is still polymerized additively.
Step-by-Step Solution:
Verification / Alternative check:
Polymer science references classify PE, PP, PVC, and PS as chain-growth polymers, in contrast to condensation polymers like polyesters, polyamides, and phenol-formaldehyde resins.
Why Other Options Are Wrong:
Each individual option names a plastic correctly produced by addition polymerization; hence only the combined choice covers them all.
Common Pitfalls:
Assuming PVC is condensation because of chlorine presence; confusing chain-growth with step-growth mechanisms; overlooking catalyst roles (e.g., Ziegler–Natta) that still operate via addition pathways.
Final Answer:
All of these
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