Identify the non-condensation polymer: Among the following, which polymer is NOT formed by condensation (step-growth) polymerisation?
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ATeflon
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BNylon-66
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CDacron (PET)
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DPolycarbonate
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EPhenolic resin (Bakelite)
Answer
Correct Answer: Teflon
Explanation
Introduction / Context:Classifying polymers by mechanism avoids confusion when predicting properties. Teflon (PTFE) is a classic addition (chain-growth) polymer from tetrafluoroethylene, whereas nylon-66, PET (Dacron), polycarbonate, and phenolic resin are condensation products formed via step-growth reactions involving functional groups and small-molecule elimination or exchange.
Given Data / Assumptions:
- Teflon forms by radical or coordination addition of tetrafluoroethylene.
- Nylon-66 forms from adipic acid and hexamethylene diamine.
- Dacron (PET) forms from terephthalate and ethylene glycol.
- Polycarbonate and phenolic resins are step-growth systems.
Concept / Approach:Select the polymer produced without elimination of small molecules (i.e., addition polymer). PTFE meets this criterion. The others are well-known condensation polymers in standard syllabi.
Step-by-Step Solution:
List mechanisms for each option.Identify PTFE as addition polymer of TFE.Choose Teflon.Verification / Alternative check:Polymer handbooks place PTFE among vinyl addition polymers; the others appear under step-growth families.
Why Other Options Are Wrong:
- Nylon-66/PET/polycarbonate/phenolic: all formed via condensation or transesterification/condensation reactions.
Common Pitfalls:Assuming “high-performance” implies condensation; mechanism depends on monomer functionality, not performance level.
Final Answer:Teflon