One-Pot Synthesis of Star Copolymers by the Combination of Metal-Free ATRP and ROP Processes.

Gorkem Yilmaz

doi:10.3390/polym11101577

Abstract

A completely metal-free strategy is demonstrated for the preparation of star copolymers by combining atom transfer radical polymerization (ATRP) and ring-opening polymerization (ROP) for the syntheses of block copolymers. These two different metal-free controlled/living polymerizations are simultaneously realized in one reaction medium in an orthogonal manner. For this purpose, a specific core with functional groups capable of initiating both polymerization types is synthesized. Next, vinyl and lactone monomers are simultaneously polymerized under visible light irradiation using specific catalysts. Spectral and chromatographic evidence demonstrates the success of the strategy as star copolymers are synthesized with controlled molecular weights and narrow distributions.

Highlights

Synthesis of complex molecular architectures with well-defined structures and controlled molecular weight characteristics has been an attractive research area in the last decade [1,2]
Among the controlled polymerization (CP) techniques applied, atom transfer radical polymerization (ATRP) has been the most widely studied strategy, as it is applicable to a wide range of vinyl monomers and provides the syntheses of halide-chain-end polymers with narrow molecular weight distributions [12]
ATRP and ring-opening polymerization (ROP) processes, first, a corestar with appropriate for both metal-free polymerizations processes, first, a core with appropriate functional groups for both polymerizations was synthesized according to modified procedures reported in the literature [45,46]

Summary

Introduction

Synthesis of complex molecular architectures with well-defined structures and controlled molecular weight characteristics has been an attractive research area in the last decade [1,2]. Among the CP techniques applied, atom transfer radical polymerization (ATRP) has been the most widely studied strategy, as it is applicable to a wide range of vinyl monomers and provides the syntheses of halide-chain-end polymers with narrow molecular weight distributions [12]. It requires large amounts of low oxidation state copper complexes (CuX/L) for the polymerization to occur (Scheme 1a). The major drawbacks of utilizing conventional ATRP is the vulnerability of the catalyst in oxidative conditions, requiring a high catalyst load, which should be removed after polymerization This is especially important for the preparation of polymers, which will be used for bioapplications. Both direct and indirect pathways should be considered

Methods

Results

Conclusion