Buna-S rubber nomenclature: in industrial and polymer science terminology, Buna-S is more commonly referred to as which material?

Introduction / Context:
Buna-S is a historically important synthetic rubber that helped transform tire and general rubber industries. The question tests your knowledge of trade names and corresponding chemical identities in elastomers. Recognising these equivalences is crucial for materials selection, processing parameters, and understanding performance trade-offs in real engineering applications.

Given Data / Assumptions:

• Buna-S is the legacy/trade description.
• Options include different polymers with distinct chemistries and properties.
• We must map Buna-S to its standard chemical name.

Concept / Approach:
“Buna” historically refers to butadiene-based rubbers; the letters after the hyphen indicate comonomers. Buna-S specifically denotes a copolymer synthesised from butadiene (Bu) and styrene (St), hence SBR: styrene–butadiene rubber. SBR is produced predominantly by emulsion polymerisation (hot or cold processes) and is widely used in passenger car tire treads, footwear, belts, and many moulded goods owing to balanced abrasion resistance and cost.

Step-by-Step Solution:
Identify the historical naming scheme: Buna-S → butadiene + styrene.Match to the modern, generic name: styrene–butadiene rubber (SBR).Exclude other candidates that do not share the same monomer set.

Verification / Alternative check:
Materials handbooks consistently equate Buna-S with SBR. Product datasheets for tires and industrial rubbers also use SBR as the generic name.

Why Other Options Are Wrong:
Polyurethane (PU): formed from diisocyanates and polyols; not butadiene/styrene based.Teflon (PTFE): fluoropolymer derived from tetrafluoroethylene; very different family.Bakelite: thermosetting phenolic resin; not an elastomer.

Common Pitfalls:
Confusing Buna-S (SBR) with Buna-N (NBR, nitrile rubber from butadiene + acrylonitrile). The suffix letter(s) matter.

Final Answer:
SBR (styrene–butadiene rubber)