1-Butene
But-1-ene is an alkene easily condensed to give a colorless liquid.It is classified as a linear alpha-olefin (terminal alkene).Polymerization of but-1-ene gives polybutylene, which is used to make piping for domestic plumbing.[4] It has also been used as a precursor to polypropylene resins, butylene oxide, and butanone.[5] But-1-ene is produced by separation from crude C4 refinery streams and by ethylene dimerization.