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  • Common name:
    CSM or Hypalon
  • Common chemical composition:
    Chlorosulfonated polyethylene

Fields of application

They include sectors such as automotive, construction, electricity and cable. For example, they can be used for the production of pipes for the transport of extremely aggressive inorganic chemicals or for the production of insulating sheaths.
They can also be used for the production of waterproofing membranes for roofs, water reservoirs or tanks.
They can be used to create rubberized fabrics or coloured profiles for the construction industry.
They are also used in the sector for food-grade items or in conveyor belts for minerals.

General properties

The CSM molecule contains chlorine and sulfonyl chloride (-SO2Cl). It is obtained by treating a boiling solution of polyethylene and carbon tetrachloride with gaseous chlorine and sulfur dioxide. A polymer with 29% to 43% chlorine and 1% to 1.5% sulfur is thus produced. The properties of the various types of CSM mainly depend on:

  • Degree of branching of the polyethylene used. Low density polyethylenes contain a large amount of branched chains; those with high density are instead more linear.
  • Chlorine content. Higher chlorine content means greater oil and flame resistance but less flexibility at low temperatures.

In general, they perform well under a fairly wide range of temperatures (-40, +135°C). They exhibit good weathering and ozone resistance.
These polymers show low permeability to steam and gases.
They are compatible with silicone oils, aliphatic hydrocarbons, organic and inorganic acids. They also have good dielectric properties.

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