PCL(4k)-PEG(3k)-ALK is a click chemistry polymer which is reactive with azide in the presence of Cu catalyst to form a stable triazole linkage. The polymer is bidoegradable and amphipathic. In water, the polymer can self-assemble to form micelles with core and shell made of polycaprolactone (PCL) and PEG, respectively. It can be used to encapsulate hydrophobic drugs for targeted drug delivery. Reagent grade, for research purpose.