polybutene vs polybutylene

polybutene and polybutylene both are nouns.

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

As nouns, polybutene and polybutylene are synonyms defined as:

polybutene and polybutylene: a polymer of butylene; used in lubricants and synthetic rubber

polybutene (noun)	polybutylene (noun)
a polymer of butylene; used in lubricants and synthetic rubber	a polymer of butylene; used in lubricants and synthetic rubber