A simple and facile strategy for the functionalization of commercial poly(epsilon-caprolactone) diols (PCLs) with pendant functionalities at the polymer chain termini is described. Well-defined allyl-functionalized PCLs with varying numbers of allyl end-block side-groups were synthesized by cationic ring-opening polymerization of allyl glycidyl ether using PCL diols as macroinitiators. Further functionalization of the allyl-functionalized PCLs was realized via the UV-initiated radical addition of a furan-functionalized thiol to the pendant allyl functional groups, showing the suitability for post-modification of the PCL materials. Changes in polymer structure as a result of varying the number of pendant functional units at the PCL chain termini were demonstrated. (c) 2017 Wiley Periodicals, Inc.