Polyisobutylene, also known as “PIB” or polyisobutene, (C4H8)n), is the homopolymer of isobutylene or 2-methyl-1-propene, on which butyl rubber is based. Polyisobutylene is produced by catalytic polymerization of a hydrocarbon C4 stream from petrochemical origin, very pure and with a high content of isobutylene and some isoprene. The formula for PIB is: (-CH2-C(CH3)2-)n. A well-controlled process is of great importance to secure a narrow molecular weight distribution. PIB’s are classified by their Molecular Weight (g/mol). Polyisobutene (PIB) is used in, lubricants (two stroke oil & greases), adhesives and sealants, LDPE wrapping films, corrosion protection, cosmetics, rubber, asphalt applications, plastic compounds, electrical insulation in wires & cables and food additives (gum base).


PIB has some unique properties:

  • Excellent barrier to moisture and gas
  • Elasticity over a wide temperature range – even at low temperatures
  • Permanent tackiness
  • Excellent aging characteristics
  • Cold flow for self-healing materials and hermetic sealing of rough surfaces
  • High up-take of fillers
  • Odourless and colourless for superior aesthetics
  • PIB is a non-curable polymer – except by radiation curing – and certain grades of the MW range are very viscous and have high damping properties
  • No engine deposits, low smoke emission and can be used in two-stroke oil