Phenol–formaldehyde resins: the condensation polymer made from phenol and formaldehyde is commonly called what?

Introduction / Context:
Identifying polymer families by their synthesis routes is a core skill. Phenol–formaldehyde resins are classic thermosets prepared via condensation polymerisation, and they paved the way for modern plastics. This question checks if you can link the chemistry to its well-known commercial name.

Given Data / Assumptions:

• Monomers: phenol and formaldehyde.
• Process: condensation polymerisation with crosslinking.
• We compare with unrelated polymer systems.

Concept / Approach:
Phenol and formaldehyde react to form resols/novolacs which cure to three-dimensional networks known commercially as Bakelite. Teflon (PTFE) is a fluoropolymer made by addition polymerisation of tetrafluoroethylene, polyester is a broad class often from diacids and diols, and nylon-66 is a polyamide from hexamethylene diamine and adipic acid.

Step-by-Step Solution:
Identify the given monomers → phenol + formaldehyde.Recognise condensation with crosslinking → thermoset.Map to trade name → Bakelite.Eliminate PTFE, polyester, nylon-66 as different chemistries.

Verification / Alternative check:
Standard polymer textbooks and historic accounts credit Bakelite as one of the first synthetic plastics, based on phenol–formaldehyde chemistry.

Why Other Options Are Wrong:
Teflon: fluoropolymer by addition; unrelated monomers.Polyester: diol + diacid/anhydride; not phenol–formaldehyde.Nylon-66: polyamide from diamine + diacid.

Common Pitfalls:
Assuming all condensation polymers are “polyesters” or “polyamides”; overlooking crosslinked resin behaviour of phenolics.

Final Answer:
Bakelite