Bakelite is correctly identified as which type of polymeric material?
-
ASame as polytetrafluoroethylene (PTFE)
-
BAn inorganic polymer
-
CA thermoset phenol–formaldehyde resin
-
DNot a polymer at all
-
EA linear polyolefin
Answer
Correct Answer: A thermoset phenol–formaldehyde resin
Explanation
Introduction / Context:Bakelite is one of the earliest commercial plastics and a prototypical thermosetting resin formed by the condensation of phenol with formaldehyde. It established the modern concept of crosslinked polymer networks with good heat resistance, electrical insulation, and dimensional stability.
Given Data / Assumptions:
- Bakelite is a crosslinked network (thermoset) produced via step-growth condensation.
- Once cured, it cannot be remelted or reshaped.
- It is organic (based on phenolic chemistry), not an inorganic polymer.
Concept / Approach:Match the historical and chemical identity: phenol–formaldehyde → thermoset phenolic. The other options deliberately mismatch polymer class or falsely equate Bakelite with unrelated materials.
Step-by-Step Solution:Identify Bakelite’s chemistry (phenolic condensation).Recognise crosslinked thermoset behaviour.Select “thermoset phenol–formaldehyde resin.”
Verification / Alternative check:Handbooks and historical accounts of plastics clearly define Bakelite as the first fully synthetic thermoset.
Why Other Options Are Wrong:PTFE: fluoropolymer; unrelated.Inorganic polymer: incorrect classification here.Not a polymer: inaccurate; it is a polymeric network.Polyolefin: unrelated chemistry and structure.
Common Pitfalls:Confusing “phenolic” with “phenyl” (aromatic ring) and misclassifying the resin as a linear thermoplastic.
Final Answer:A thermoset phenol–formaldehyde resin