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