A new method called reverse iodine transfer polymerization (RITP), based on the in situ generation of transfer agents using molecular iodine I(2), was applied to the synthesis of poly(vinylbenzyl chloride). Well-defined diblock copolymers poly(vinylbenzyl chloride)-b-polystyrene with different chain lengths were then successfully produced through sequential polymerization of styrene. The polydispersity index values M(w)/M(n), ranged from 1.4 to 1.6 for all the homopolymers and diblock copolymers. The diblock copolymers could be synthesized with equally good results by starting with either poly(vinylbenzyl chloride) or polystyrene as macrotransfer agents. The diblock copolymers were then quaternized with triethylamine to prepare cationic amphiphilic diblock copolymers. (C) 2010 Elsevier Ltd. All rights reserved.