disassociate vs split up

disassociate is not a noun while split up is a noun.

Word	Noun	Adjective	Verb	Adverb
disassociate	No	No	Yes	No
split up	Yes	No	Yes	No

As verbs, split up is a hypernym of disassociate; that is, split up is a word with a broader meaning than disassociate:

Other hypernyms of disassociate include break, break up, part, separate, split.

disassociate (noun)	split up (noun)
	an increase in the number of outstanding shares of a corporation without changing the shareholders' equity

disassociate (verb)	split up (verb)
part; cease or break association with	become separated into pieces or fragments
	get a divorce; formally terminate a marriage
	discontinue an association or relation; go different ways
	separate into parts or portions