Identify the non-condensation polymer:\nAmong the following, which polymer is NOT formed by condensation (step-growth) polymerisation?

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:

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