stubborn vs refractory

stubborn is not a noun while refractory is a noun.

Word	Noun	Adjective	Verb	Adverb
stubborn	No	Yes	No	No
refractory	Yes	Yes	No	No

As adjectives, stubborn and refractory are synonyms defined as:

stubborn (noun)	refractory (noun)
	lining consisting of material with a high melting point; used to line the inside walls of a furnace

stubborn (adjective)	refractory (adjective)
tenaciously unwilling or marked by tenacious unwillingness to yield	stubbornly resistant to authority or control
not responding to treatment	temporarily unresponsive or not fully responsive to a process or stimulus
	not responding to treatment