1) What is the common name of polyisoprene?

A) Natural rubber

B) Synthetic rubber

C) Nylon

D) Teflon


  • Polyisoprene is a polymer of isoprene (C₅H₈), which is also called 2-methyl-1,3-butadiene.
  • In nature, polyisoprene is obtained from the latex of the rubber tree (Hevea brasiliensis).
  • This naturally occurring polymer is elastic, flexible, and water-resistant, making it highly useful in tires, footwear, and many industrial products.
  • Therefore, the common name of polyisoprene is Natural Rubber.

 

  • B) Synthetic rubber → Artificially made polymers like Buna-S, Buna-N, Neoprene, etc. These are not polyisoprene.
  • C) Nylon → Polyamide (completely different polymer, made from diamines & dicarboxylic acids).
  • D) Teflon → Poly(tetrafluoroethylene), abbreviated PTFE, used for non-stick coatings.

Important Polymers – Monomers & Common Names

Polymer

Monomer(s)

Common Name / Trade Name

Polyisoprene

Isoprene (2-methyl-1,3-butadiene)

Natural Rubber

Polychloroprene

Chloroprene (2-chloro-1,3-butadiene)

Neoprene (Synthetic Rubber)

Polybutadiene

Butadiene

Synthetic Rubber (SBR with styrene)

Buna-S

Butadiene + Styrene

Styrene-Butadiene Rubber (SBR)

Buna-N

Butadiene + Acrylonitrile

Nitrile Rubber (Oil-resistant)

Polytetrafluoroethylene

Tetrafluoroethylene

Teflon (Non-stick coating)

Polystyrene

Styrene

Thermocol / Disposable plastics

Polyvinyl chloride (PVC)

Vinyl chloride

PVC pipes, insulation

Polyethylene (PE)

Ethene (ethylene)

Plastic bags, bottles

Low-Density PE (LDPE)

Ethene (under high pressure)

Carry bags, film wrap

High-Density PE (HDPE)

Ethene (Ziegler-Natta catalyst, low pressure)

Containers, pipes

Polypropylene (PP)

Propylene

Buckets, ropes

Polymethyl methacrylate

Methyl methacrylate

Plexiglass / Acrylic glass

Polyacrylonitrile (PAN)

Acrylonitrile

Orlon / Acrilan (Synthetic wool)

Polyvinyl alcohol (PVA)

Vinyl alcohol

Adhesives

Polycarbonate (PC)

Bisphenol-A + Phosgene

Bulletproof glass, CDs

Nylon-6

Caprolactam

Synthetic fibre (Nylon)

Nylon-6,6

Hexamethylenediamine + Adipic acid

Strong synthetic fibre

Terylene / Dacron

Ethylene glycol + Terephthalic acid

Polyester fibre

Bakelite

Phenol + Formaldehyde

Electrical switches, combs

Urea-formaldehyde resin

Urea + Formaldehyde

Adhesives, laminates

Melamine-formaldehyde

Melamine + Formaldehyde

Crockery, floor tiles

Alkyd resins

Polyhydric alcohol + Polybasic acid

Paints, varnishes

Glyptal

Ethylene glycol + Phthalic acid

Paints, coatings

 

✅ Key Notes for Exams:

  • Natural rubber → polyisoprene (cis-1,4 addition)
  • Vulcanization of rubber → with sulfur improves strength & elasticity
  • Teflon → PTFE, chemically inert, used in non-stick cookware
  • Bakelite → first synthetic polymer (thermosetting plastic)
  • Nylon & Terylene → condensation polymers (fibres)
  • Polyethylene & PVC → addition polymers (plastics)


 So the Answer is -Natural rubber