PCL(6k)-PEG(4k)-PCL(6k) is a self-assembling triblock copolymer containing a hydrophilic PEG block in between hydrophobic polycaprolactone (PCL) blocks. The polymer has terminal hydroxyls for further derivatization. It can be used for drug delivery formulation. The ester bonds of the polymer can be cleaved via hydrolysis. Reagent grade, for research purpose.