PCL(2k)-PEG(2k)-NH2 is a linear monofunctional amphiphilic block copolymer. The N-terminus is reactive with an NHS ester readily or with a carboxylic acid (COOH) in the presence of HATU or EDC. The polymer can self assemble in water to form nanomicellar which can be used for controlled release drug delivery. Reagent grade, for research purpose.