Efficient Synthesis of Single-Chain Polymer NanoparticlesviaAmide Formation

Ana Sanchez-Sanchez,José A Pomposo

doi:10.1155/2015/723492

Abstract

Single-chain technology (SCT) allows the transformation of individual polymer chains to folded/collapsed unimolecular soft nanoparticles. In this work we contribute to the enlargement of the SCT toolbox by demonstrating the efficient synthesis of single-chain polymer nanoparticles (SCNPs)viaintrachain amide formation. In particular, we exploit cross-linking between active methylene groups and isocyanate moieties as powerful “click” chemistry driving force for SCNP construction. By employing poly(methyl methacrylate)- (PMMA-) based copolymers bearingβ-ketoester units distributed randomly along the copolymer chains and bifunctional isocyanate cross-linkers, SCNPs were successfully synthesized at r.t. under appropriate reaction conditions. Characterization of the resulting SCNPs was carried out by means of a combination of techniques including size exclusion chromatography (SEC), infrared (IR) spectroscopy, proton nuclear magnetic resonance (1H NMR) spectroscopy, dynamic light scattering (DLS), and elemental analysis (EA).

Highlights

Single-chain technology (SCT) is a new paradigm for the future construction of smart and autonomous soft nanodevices [1]
First reports about the synthesis of permanent single-chain polymer nanoparticles (SCNPs) by means of the intrachain homocoupling technique under high dilution conditions by Mecerreyes et al relied on the use of poly(styren), poly(alkyl methacrylate), and poly(εcaprolactone)-based precursors containing vinyl reactive functional groups [12]
The synthesis of poly(methyl methacrylate)- and poly(styrene)-based SCNPs by intramolecular cross-linking of isocyanate-functionalized copolymers with diamines via urethane formation was reported by Beck et al [34]

Summary

Introduction

Single-chain technology (SCT) is a new paradigm for the future construction of smart and autonomous soft nanodevices [1]. In this work we contribute to the enlargement of the SCT toolbox by demonstrating the efficient synthesis of single-chain polymer nanoparticles (SCNPs) via intrachain amide formation. By employing poly(methyl methacrylate)- (PMMA-) based copolymers bearing β-ketoester units distributed randomly along the copolymer chains and bifunctional isocyanate cross-linkers, SCNPs were successfully synthesized at r.t. under appropriate reaction conditions.

Results

Conclusion