Neoprene (CR), also called polychloroprene or chloroprene rubber, synthetic rubber produced by the polymerization (or linking together of single molecules into giant, multiple-unit molecules) of chloroprene. A good general-purpose rubber, neoprene is valued for its high tensile strength, resilience, oil and flame resistance, and resistance to degradation by oxygen and ozone; however, its high cost limits its use to special-properties applications.