PCL(10k)-PEG(5k)-MAL is an amphiphilic block copolymer with terminal maleimide which can react with thiol (SH) via formation of thioether bond. In water, the polymer can form micelles which contains hydrophobic core (polycaprolactone (PCL)) and hydrophilic shell (PEG). It can be used to prepare drug nanocarrier in drug delivery system. Reagent grade, for research purpose.