polemical vs polemic

polemical is not a noun while polemic is a noun.

Word	Noun	Adjective	Verb	Adverb
polemical	No	Yes	No	No
polemic	Yes	Yes	No	No

As adjectives, polemical and polemic are synonyms defined as:

polemical (noun)	polemic (noun)
	a controversy (especially over a belief or dogma)
	a writer who argues in opposition to others (especially in theology)

polemical (adjective)	polemic (adjective)
of or involving dispute or controversy	of or involving dispute or controversy