Cloroprene rubber

Chloroprene rubber (Neoprene®, Baypren®, Butaclor®) CR (Chloroprene Rubber) is the general name given to a number of unsaturated synthetic rubber types based on polychloroprene and made by emulsion curing.
Nowadays chloroprene rubber is made by many companies in various countries and is sold under several trade names, either as a solid or as latex.
Chloroprene rubber shows a marked tendency to chrystallize. This happens because small crystals form inside macromolecules; its effect is a more or less marked hardening which affects rubber as well as the raw rubber mixture and the vulcanized product at room temperature and especially at lower temperatures.


  • Articles made of chloroprene rubber usually feature high flame-retardant properties, good resistance to ozone, weathering, ageing and chemicals, intermediate resistence to oils, good mechanical properties and good elasticity even at very low temperatures.
  • Impact strength: 20 to 50%
  • Extensibility: 100 to 800% and beyond
  • Heat resistance: up to +100°C, for a short while also +120°C. If heated for a long time in presence of oxygen, this kind of rubber becomes much harder.
  • Resistance to low temperatures: up to -40°C.
  • Electrical properties: like NBR, chloroprene rubber is a semiconductor, so that vulcanized CR items are not recommended for electrical insulation.
  • Gas permeability: much lower than that of NR, IR, BR, SBR, EPM and EPDM rubber; quite comparable to that of NBR types.
  • Resistence to ozone, aging and weathering: vulcanized CR products of suitable composition can withstand ozone, ageing and weathering better than other unsaturated rubber types like NBR and SBR.
  • Resistence to chemicals:
    • Good resistance to:
      Paraffinic mineral oils
      Silicone-based oils and fats
      Water and aqueous solutions (specially prepared mixtures only)
      Coolants, such as ammonia, carbon dioxide and Freon®
    • Intermediate resistance to:
      Naphthenic mineral oils
      Aliphatic hydrocarbons characterized by a low molecular weight (propane, butane, gasoline)
    • Does not resist to:
      Aromatic hydrocarbons (benzol)
      Polar solvents such as ketones, esters and ethers.
      Poorly flammable liquids belonging to the HFD group.
    • Vulcanized chloroprene rubber with ordinary composition shows a rather marked tendency to absorb water; whenever this is an issue, it are less suitable than NBR and SBR.


Chloroprene rubber is used when rubber products must feature excellent flame-retardant properties and good resistance to weathering, ageing and chemicals. This is the case of belt conveyors, gaskets, hose, cylinder linings, coating in general, cable sheaths, rubberized cloth, etc.