isobutylene Syllabification: (i·so·bu·tyl·ene)Pronunciation: /ˌīsəˈbyo͞otlˌēn, /Definition of isobutylene noun Chemistry an easily liquefied hydrocarbon gas, (CH3)2C=CH2, used in the making of butyl rubber. isobutylene in other Oxford dictionaries Definition of isobutylene in the British & World English dictionary
