Chloroprene

Chloroprene, or 2-chloro-1,3-butadiene, is a volatile, colorless to faintly yellow liquid that serves as the principal monomer for neoprene rubber. Its chemical formula is C4H5Cl (molar mass about 88.45 g/mol). The molecule is a conjugated diene containing a chlorine substituent, which contributes to its high reactivity in radical polymerizations.

Chloroprene is produced commercially through multi-step processes starting from butadiene. The typical route involves chlorination of a butadiene-derived intermediate followed by dehydrochlorination to yield the conjugated diene. The product is handled under inhibitors to prevent premature polymerization; storage and transport require low temperatures and oxygen-free conditions.

Chloroprene is highly reactive in free-radical polymerizations and forms neoprene upon polymerization with sulfur and coagents. It can be polymerized in emulsion or solution systems to give elastomeric plastics used in a wide range of products.

Main use is to polymerize to neoprene rubber used in wetsuits, hoses, electrical insulation, gaskets; it is also used to make coatings, sealants, specialty polymers, and adhesives.

Health and safety: IARC classifies chloroprene as possibly carcinogenic to humans (Group 2B). Hazards include irritation of eyes, skin, and the respiratory tract. It is flammable and can polymerize if not inhibited; occupational exposure should be minimized. Spills should be contained and removed with proper ventilation.