Neutral, anionic, cationic, and zwitterionic diblock copolymers featuring poly(2-methoxyethyl acrylate) “hydrophobic” segments

Abstract

Amphiphilic diblock copolymers incorporating “hydrophobic” poly(2-methoxyethyl acrylate) (PMEA) and hydrophilic neutral poly(ethylene glycol) monomethyl ether (mPEG), anionic poly(acrylic acid) (PAA) and poly(methacrylic acid) (PMAA), cationic poly(2-dimethylaminoethyl methacrylate) (PDMAEMA), and zwitterionic poly(3-(N-(2-methacryloyloxyethyl)-N,N-dimethylammonio)propane sulfonate) (PDMAPS) blocks are constructed. mPEG, poly(tert-butyl acrylate) (PtBA), and poly(tert-butyl methacrylate) (PtBMA) macroinitiators are chain extended with 2-methoxyethyl acrylate (MEA) employing copper-mediated atom transfer radical polymerization (ATRP) garnishing well-defined diblock copolymers with narrow polydispersities (1.11–1.30). Selective cleavage of the tert-butyl esters affords PAA-b-PMEA and PMAA-b-PMEA. ATRP of 2-dimethylaminoethyl methacrylate (DMAEMA) from the PMEA macroinitiator results in PMEA-b-PDMAEMA while the betainisation of the latter provides zwitterionic diblock amphiphile PMEA-b-PDMAPS. Inspection of these macromolecular architectures by NMR spectroscopy and size exclusion chromatography (SEC) confirms a fairly high degree of control over the reactions emphasizing flexibility and precision of the approach.