Full definition
Polychloroprene — ISO/ASTM designation CR — the first commercially successful synthetic rubber, introduced by DuPont in 1932. CR provides an outstanding balanced combination of properties: moderate oil and fuel resistance (better than NR/SBR/EPDM, inferior to NBR/FKM), inherent flame retardancy (LOI > 26%, self-extinguishing due to ~36% chlorine content), good ozone and weather resistance, good dynamic performance, and excellent adhesive properties (base for contact cements). Temperature range: -35 to +100°C continuous (+120°C intermittent). ASTM D2000 classification: BC (standard), BE (higher temperature grades). Properties: hardness 30-90 Shore A, tensile 15-25 MPa, elongation 200-600%. Grades: W-types (general purpose), GN/GNA (crystallization-resistant for low-temp flexibility), AC (adhesive base). Limitations: attacked by aromatic solvents and chlorinated hydrocarbons, moderate cost ($3-5/kg). Applications: belt body compound (alongside EPDM), expansion joints, bridge bearings, automotive hoses, cable jacketing, wetsuits, industrial sheet, and contact adhesives. Manufacturers: Denka (Japan), Pidilite (India), Lanxess (Baypren).