Neoprene rubbers are homopolymers of chloroprene (chlorobutadiene) and were among the earliest synthetic rubbers used to produce seals. CR has good aging characteristics in ozone and weather environments, along with abrasion and flex cracking resistance.
This, combined with a broad temperature range and moderate cost, accounts for its desirability in many sealing applications for refrigerants like Freon® and ammonia.
CR is resistant to refrigerants, ammonia, Freon® ( R12, R13, R21, R22, R113, R114, R115, R134A), silicone oils, water, ozone, vegetable oils, alcohols, and low-pressure oxygen. CR has a very low resistance to mineral oils.
The chloroprene rubber O-ring is oil-resistant, heat-resistant, fire-resistant, sunlight-resistant, ozone-resistant, acid-alkali-resistant and chemical reagent-resistant.
The disadvantage is poor cold resistance and storage stability. It is mainly suitable for air conditioning, refrigerants such as dichlorodifluoromethane and ammonia, dilute acid and silicone grease lubricants.
CR is not effective in aromatic and oxygenated solvent environments. Neoprene can be compounded for service temperatures of -40°C to + 110°C (-40°F to +230°F).
Most elastomers are either resistant to deterioration from exposure to petroleum based lubricants or oxygen. Neoprene is unusual in having limited resistance to both.