One antonym for the word "communalize" is "individualize," which means to make something private, personal or individualistic. Another antonym is "privatize," which means to transfer ownership or control of a public property or service to a private entity. Finally, "decentralize" can also be an antonym of "communalize," as it refers to the transfer of power or authority from a central authority to local or regional levels.
Overall, these antonyms highlight the different ways that resources, power, and control can be distributed across a society. Whereas communalize suggests a move towards shared ownership and control, individualize, privatize and decentralize all suggest a move toward greater individual control over resources and decisions.