friction vs frictional

friction is a noun but frictional is not a noun.

Word	Noun	Adjective	Verb	Adverb
friction	Yes	No	No	No
frictional	No	Yes	No	No

friction (noun)	frictional (noun)
effort expended in moving one object over another with pressure
the resistance encountered when one body is moved in contact with another
a state of conflict between persons

friction (adjective)	frictional (adjective)
	pertaining to or worked or produced by friction