Synthesis and characterization of well‐defined optically active methacrylic diblock copolymers

Abstract

A new, simple, and cost-effective approach toward the development of well-defined optically active diblock copolymers based on methacrylate monomers is described for the first time. Starting from the low-cost optically active (S)-(À)-2-methyl-1-butanol, a new optically active methacrylic monomer, namely, (S)-(þ)-2-methyl-1-butyl methacrylate [(S)-(þ)-MBuMA], was synthesized. Reversible addition fragmentation chain transfer polymerization was then used for preparing well-defined poly[(S)-(þ)-MBuMA] homopolymers and watersoluble diblock copolymers based on [(S)-(þ)-MBuMA] and the hydrophilic and ionizable monomer 2-(dimethyl amino)ethyl methacrylate (DMAEMA). The respective homopolymers and diblock copolymers were characterized in terms of their molecular weights, polydispersity indices, and compositions by size exclusion chromatography and 1 H NMR spectroscopy. Polarim-etry measurements were used to determine the specific optical rotations of these systems. The structural and compositional characteristics of micellar nanostructures possessing an optically active core generated by p((S)-(þ)-MBuMA)-b-p(DMAEMA) chains characterized by predetermined molecular characteristics may be easily tuned to match biological constructs. Consequently, the aggregation behavior of the p[(S)-(þ)-MBuMA]-bp[DMAEMA] diblock copolymers was investigated in aqueous media by means of dynamic light scattering and atomic force microscopy, which revealed the formation of micelles in neutral and acidified aqueous solutions. V C 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 50: [4215][4216][4217][4218][4219][4220][4221][4222] 2012