PCL(5k)-PEG(1k)-ALK is an alkyne terminated block copolymer with hydrophobic polycaprolactone (PCL) and hydrophilic PEG blocks. The alkyne can react with azide in the presence of copper catalyst to form a covalent triazole bond. The biodegradable polymer can be used to prepare drug-loaded nanoparticles for drug delivery. Reagent grade, for research purpose.