PCL(1k)-PEG(3k)-MAL is a linear monofunctional amphiphile polymer which can form micelles in water. The polymer contains a hydrophobic block (polycaprolactone (PCL)) and hydrophilic block (PEG) which can be used to prepare nanoparticles for drug delivery. The maleimide group is reactive with thiol at pH 6.5-7.5 to form a thioether bond. Reagent grade, for research purpose.