What does butylene mean?
Butylene is the name given to any of several closely related gaseous hydrocarbons with the chemical formula C4H8. Each isomer contains exactly one carbon-carbon double bond, which makes it an alkene — chemically more reactive than its saturated cousin butane. The best-known forms are 1-butylene, two variants of 2-butylene, and the branched isobutylene. All are colourless, flammable gases that do not occur meaningfully in nature; they are produced industrially, chiefly by cracking or refining petroleum. Their main commercial value lies as building blocks: they feed into the manufacture of plastics, synthetic rubber (notably butyl rubber from isobutylene), solvents, and additives such as butylene glycol found in cosmetics. The term derives ultimately from butyric acid, named after butter, reflecting early nineteenth-century organic chemistry's habit of naming compounds by their apparent kinship. Though firmly technical in register, butylene surfaces in consumer life through plumbing pipes and skincare ingredient lists.
nounButylene is any of several flammable, colourless gaseous hydrocarbons with the formula C4H8, each containing one carbon-carbon double bond; the principal isomers are 1-butylene (1-butene), cis- and trans-2-butylene, and isobutylene.
- (Chemistry) Any of the isomeric acyclic alkenes of formula C4H8 — 1-butylene, cis-2-butylene, trans-2-butylene, or isobutylene — flammable gases obtained chiefly from petroleum refining or cracking.
- (Commercial usage, often in compounds) A feedstock or constituent in industrial products, as in polybutylene piping, butylene glycol in cosmetics, or butyl rubber manufacture.
"The refinery cracked heavier fractions to yield butylene for the plastics plant downstream."
"Steam cracking of naphtha produces a mixture containing ethylene, propylene, and butylene."
"The plumber recommended replacing the ageing polybutylene pipes before they failed."
Used when referring collectively to the several isomeric butylenes, e.g. in discussions of refinery streams.
"The cracked stream was rich in butylenes, which were separated for further processing."
That squeaky-clean cosmetic ingredient 'butylene glycol' on your moisturiser's label starts life as the same industrial gas used to make synthetic rubber and plastics.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of butylene
The word was coined in the nineteenth century within the then-new vocabulary of organic chemistry. It combines 'butyl' — itself derived from butyric acid, whose name traces back through Latin butyrum to Greek boutyron, meaning 'butter', because the acid was first isolated from rancid butter — with the suffix '-ene', which chemists used to denote hydrocarbons containing a double bond. The same pattern produced ethylene and propylene, making these names true siblings rather than coincidental lookalikes.
Related word forms
How butylene is actually used
A technical term used mainly in chemistry, petrochemical engineering, and materials science; rarely encountered in everyday speech. In industrial contexts the individual isomers are usually named precisely (e.g. isobutylene, 1-butene), so unqualified 'butylene' most often refers to the mixture or appears within compound names such as polybutylene or butylene glycol.
Easily confused with butylene
Butane (C4H10) is a saturated alkane with only single bonds, whereas butylene (C4H8) is an unsaturated alkene containing a carbon-carbon double bond.
Ethylene is the two-carbon alkene (C2H4) used famously for fruit ripening, while butylene is the analogous four-carbon alkene.