CSM is a synthetic rubber derived from polyethylene (PE) through chlorination and the introduction of sulfonyl chloride groups. This chemical modification incorporates chlorine and sulfonyl groups into the molecular structure, enhancing resistance to chemicals, weathering, and degradation. CSM is commercially known as Hypalon (originally developed by DuPont).

Physical and Chemical Properties

• Ozone & UV Resistance: Excellent, suitable for prolonged outdoor exposure

• Chemical Resistance: Resistant to acids, alkalis, oils, and various solvents

• Heat Resistance: Continuous use at around 120–150°C and cold resistance down to -40°C

• Flame Retardancy: Self-extinguishing with low smoke emission

• Mechanical Strength: High tensile strength and tear resistance

• Gas Permeability: Low, making it suitable for gas containment applications

• Compatibility: Can be blended with other synthetic rubbers such as EPDM, CR, and NBR

Applications

• Roofing membranes

• Waterproof tarpaulins, boat covers, and truck covers

• Outdoor seals and gaskets

• Weather-resistant cable sheathing

• Chemical-resistant hoses

• Oil and industrial transfer hoses

• Industrial rollers

Advantages Compared to Other Synthetic Rubbers

• Superior long-term weathering and ozone resistance compared to CR and EPDM

• Better chemical resistance than NBR and EPDM for many chemicals

• Naturally flame-retardant without additional additives

• More expensive than CR and EPDM but offers higher durability in harsh outdoor and chemical environments