impermanent vs temporary

impermanent is not a noun while temporary is a noun.

Word	Noun	Adjective	Verb	Adverb
impermanent	No	Yes	No	No
temporary	Yes	Yes	No	No

As adjectives, impermanent and temporary are synonyms defined as:

impermanent (noun)	temporary (noun)
	a worker (especially in an office) hired on a temporary basis

impermanent (adjective)	temporary (adjective)
not permanent; not lasting	not permanent; not lasting
existing or enduring for a limited time only	lacking continuity or regularity