Po ly(ethylene terephthalate)-polycaprolactone block copolymer (PCL-b-PET) is a polyester with improved biodegradability. In the present paper, a new direct copolymerization method of epsilon-caprolactone (epsilon-CL) and bishydroxyethylene terephthalate (BHET) in the presence of Ti(OBu)(4) was proposed for the synthesis of PCL-b-PET. The PCL-b-PET copolymer was characterized by IR, GPC and H-1-NMR techniques, and the effects of synthesis conditions, such as temperature, reaction time and concentration of catalyst on the copolymerization were discussed.
