Methods for the synthesis of CTFE-based block copolymers through iodine transfer polymerization are disclosed. In an exemplary embodiment, a method includes reacting a fluoromonomer “M” with a chain transfer agent of the formula X—Y or Y—X—Y, wherein X represents a C1-C3 hydrocarbon, a C1-C6 hydrofluorocarbon, C1-C6 hydrochlorofluorocarbon, or C1-C6 fluorocarbon and Y represents iodine or bromine, in the presence of a radical initiator, to form a macro-initiator of the formula: X-poly(M)-Y or Y-poly(M)-X-poly(M)-Y, wherein poly(M) represents a polymer of the fluoromonomer. The method further includes reacting the macro-initiator with chlorotrifluoroethylene (CTFE) in the presence of a radical initiator to form a diblock or a triblock CTFE-based block copolymer of the formula: X-poly(M)-block-poly(CTFE) or PCTFE-block-poly(M)-X-poly(M)-block-PCTFE.