PCL(4k)-PEG(1k)-ALK is a biodegradable and self-assembling polymer. In water, the polymer forms micelles with polycaprolactone (PCL) (hydrophobic block) as core and PEG (hydrophilic block) as shell. The polymer can be used to prepare nanoparticles for drug delivery or nanomedicine. The alkyne terminal is reactive with azido molecule via CuAAC to form a stable triazole linkage. Reagent grade, for research purpose.