Amphiphilic Invertible Polymers and Their Applications

Abstract

Amphiphilic invertible polymers (AIPs) are novel smart macromolecules. Synthesized from short lipophilic and hydrophilic constituents that are alternately or randomly distributed along the polymer backbone, the AIP macromolecules possess an enhanced flexibility and rapidly respond to changes in an environmental polarity by changing their macromolecular conformation. By increasing a solution concentration, the AIP macromolecules self-organize into micellar assemblies that can change their physicochemical properties in response to changes in a medium polarity. The micellar assemblies from AIPs can be applied for the development of smart nanoreactors for the synthesis of metal and semiconductor nanoparticles of a controlled shape and size, as well as for the growth of fibrillar carbon nanostructures and the formation of smart nanocontainers for drug delivery. Synthetic routes to (1) amphiphilic invertible polyurethanes based on poly(ethylene glycol), polytetrahydrofuran, and 2,4-tolylene diisocyanate and (2) amphiphilic invertible polyesters based on poly(ethylene glycol) and aliphatic dicarboxylic acids were elaborated, and the corresponding polymers were successfully synthesized. The effect of reaction conditions on the reaction course and the macromolecular configuration of the resulting polymers were revealed. It was demonstrated that the chemical nature and structure of the macromolecules of the amphiphilic invertible polyurethanes and polyesters determine the self-assembly of the AIP macromolecules, both in an aqueous and organic media, resulting in a formation of micellar assemblies, which can serve as nanoreactors, nanocontainers, and nanocarriers.