One-pot synthesis of ABC type triblock copolymers via in situ click [3+2] and Diels-Alder [4+2] reactions

We report a one-pot synthesis of ABC triblock copolymers of poly(ethylene glycol)- (PEG-) polystyrene- (PS-) poly(methyl methacrylate) (PMMA), and poly(epsilon-caprolactone)- (PCL-) PS-PMMA by combining in situ click [3 + 2] and Diels-Alder [4 + 2] reactions. For this purpose, furan-protected maleimide end-functionalized PMMA, PS with alpha-anthracene and omega-azide end-functionality, and PEG or PCL with an alkyne end-functional group were reacted in N,N-dimehtylformamide (DMF) for 36 h at 120 degrees C in order to give the corresponding triblock copolymers. All polymeric precursors with narrow molecular weight distribution and well-defined chain-end functionalities were achieved from living polymerization methods, except PEG. The obtained polymers were characterized by H-1 NMR (250 MHz), gel permeation chromatography (GPC), and differential scanning calorimetry (DSC) measurements.