polybutylene vs butylene

polybutylene and butylene both are nouns.

Word	Noun	Adjective	Verb	Adverb
polybutylene	Yes	No	No	No
butylene	Yes	No	No	No

As nouns, butylene is a hypernym of polybutylene; that is, butylene is a word with a broader meaning than polybutylene:

polybutylene: a polymer of butylene; used in lubricants and synthetic rubber
butylene: any of three isomeric hydrocarbons C4H8; all used in making synthetic rubbers

Other hypernyms of polybutylene include butene.

polybutylene (noun)	butylene (noun)
a polymer of butylene; used in lubricants and synthetic rubber	any of three isomeric hydrocarbons C4H8; all used in making synthetic rubbers