Cationic polymerization of tetrahydrofuran (THF) and epichlorohydrin (ECH) was performed with peroxy initiators synthesized from bis (4,4'-bromomethyl benzoyl peroxide (BBP) or bromomethyl benzoyl t-butyl peroxy ester (t-BuBP) and AgSbF6 or ZnCl2 system at 0 degrees C to obtain the poly(THF-b-ECH) macromonomeric peroxy initiators. Kinetic studies were accomplished for poly(THF-b-ECH) initiators. Poly(THF-b-ECH-b-MMA) and poly (THF-b-ECH-b-S) block copolymers were synthesized by bulk polymerization of methyl methacrylate (MMA) and styrene (S) with poly(THF-b-ECH) initiators. The quantum chemical calculations for the block copolymers, the initiating systems of the cationic polymerization of THF and ECH were achieved using HYPERCHEM 7.5 program. The optimized geometries of the polymers were investigated with the quantum chemical calculations. Poly(THF-b-ECH) initiators having peroxygen groups were used for graft copolymerization of polybutadien (PBd) to obtain poly(THF-b-ECH-g-PBd) crosslinked graft copolymers. The graft copolymers were investigated by sol-gel analysis. Swelling ratio values of the graft copolymers in CHCl3 were calculated. The characterizations of the polymers were achieved by FTIR, H-1 NMR, GPC, SEM, TEM, and DSC techniques. (C) 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2896-2909, 2010