Polychloroprene
[CAS 9010-98-4]

Identification

• Classification: Catalysts and additives >> Polymer
• Name: Polychloroprene
• Synonyms: Chloroprene rubber; 2-Chloro-1,3-butadiene homopolymer
• Molecular Formula: (C₄H₅Cl)_n
• CAS Registry Number: 9010-98-4
• EC Number: 618-463-8
• SMILES: ClC(=C)C=C

Properties

• Density: 1.23

chemBlink Chemical Story

Polychloroprene, CAS 9010-98-4, is the synthetic elastomer commonly called chloroprene rubber or neoprene. Its history reaches back to acetylene chemistry developed by Julius Arthur Nieuwland at the University of Notre Dame. After DuPont acquired rights related to Nieuwland's work, a research team including Wallace Carothers and Arnold Collins developed chloroprene, 2-chloro-1,3-butadiene, and its rubbery polymer. DuPont announced the new synthetic rubber in 1931.

The early product was sold as DuPrene. Process improvements reduced odor and manufacturing cost, and the material later became known as Neoprene. Historical accounts identify polychloroprene as the first synthetic rubber polymer commercially marketed in the United States, making it an important milestone in the effort to create industrial alternatives to natural rubber.

Polychloroprene is made by polymerizing chloroprene, commonly by aqueous free-radical emulsion processes. The chlorine substituent changes the behavior of the diene polymer compared with hydrocarbon rubbers. Chloroprene rubber offers a useful balance of oil, weather and ozone resistance together with mechanical strength and elasticity. It does not maximize every property, but its broad balance is precisely why it became a versatile specialty elastomer.

Applications include hoses, seals, gaskets, wire and cable coverings, coated fabrics, adhesives and foam products. Foamed neoprene is familiar in protective and aquatic garments because closed-cell material combines flexibility with thermal insulation.

Commercial formulations can contain fillers, plasticizers, curing agents and other additives, so a finished neoprene article is not simply pure CAS 9010-98-4. Polychloroprene's story is one of the foundational successes of industrial polymer chemistry.

References:
1. Carothers WH, Williams I, Collins AM, Kirby JE. Acetylene Polymers and Their Derivatives. II. A New Synthetic Rubber: Chloroprene and Its Polymers. J Am Chem Soc. 1931.
2. University of Notre Dame, The Naturalist: Rev. Julius A. Nieuwland, CSC.
3. U.S. International Trade Commission. Polychloroprene Rubber from Japan, Publication 3786, 2005.
4. Wypych G. Handbook of Polymers. 2nd ed. Elsevier, 2016.

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