fragmentize vs split up

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

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

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

Other hypernyms of fragmentize include break, come apart, fall apart, separate.

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

fragmentize (verb)	split up (verb)
break or cause to break into pieces	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