13butadiene

1,3-butadiene, often written as 1,3-butadiene and commonly simply as butadiene, is an organic compound with the formula C4H6. It is a colorless, highly flammable gas at room temperature. The molecule is a conjugated diene, CH2=CH-CH=CH2, in which two double bonds are separated by a single bond. This arrangement gives it notable reactivity, including rapid polymerization and the ability to undergo different modes of addition during chain growth.

Production and occurrence: Most 1,3-butadiene is produced from refinery C4 streams derived from steam cracking of naphtha and gas oils. It is primarily formed by dehydrogenation of butenes or butanes over suitable catalysts, followed by separation and purification to obtain the monomer for industrial use. The feedstock and process conditions control the proportions of butadiene and other C4 olefins in the product stream.

Uses: The principal application of 1,3-butadiene is as a monomer for synthetic rubber and plastics. It polymerizes to give polybutadiene and copolymers such as styrene-butadiene rubber (SBR) and nitrile rubber (NBR), which are important in tires, footwear, adhesives, and various elastomeric products. It also serves as a chemical intermediate in the production of other polymers and specialty chemicals.

Safety and environmental aspects: 1,3-butadiene is classified as a human carcinogen by several health agencies and should be handled with strict control of exposure. It is a flammable volatile organic compound that can form explosive mixtures with air. Storage and handling require inhibitors or stabilizers to prevent unwanted polymerization, and emissions are regulated to minimize environmental impact.

Properties: Molecular weight about 54.1 g/mol; boiling point around -6 °C. It exists as a gas at room temperature and is typically managed as a stabilized liquid or cryogenic form for larger-scale use.