They are used as starting materials in the syntheses of alcohols, plastics, laquers, detergents, and fuels. The most important alkenes for the chemical industry are ethene, propene and 1,3-butadiene.
By far the most important use of alkenes is in the making of plastics as plastics are used in almost everything.
Explanation:
Alkenes themselves aren't used much in everyday life however Alkenes are very important to industrial synthesis as it is relatively easy to turn them into other things.
Alkenes can be turned into polymers or plastics through addition reactions and the most common ethene is turned into everything from plastic bags to bottles.
Alkenes can also be turned into alcohols. most commonly propene is used as a feedstock to produce butanol and other products useful in industry or for production
