A new generation of block copolymers were synthesized starting with depolymerized PET by glycolysis with some oligomeric diols. alpha,omega-Dihydroxy poly(dimethyl siloxane)s, hexylene glycol, poly(ethylene oxide)glycols, and ethylene glycol were used as diols. The dihydroxy-terminated depolymerization products containing a terephthalyl group and oligomeric diols were used to prepare a diradicalic macroinitiator (MI). These MIs were used to polymerize the styrene monomer. The new block copolymers obtained were characterized by physical and chemical methods and mechanical and thermal analyses. (C) 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 648-653, 2000.