Supramolecular Triblock Copolymers Through the Formation of Hydrogen Bonds: Synthesis, Characterization, Association Effects in Solvents of Different Polarity.

Spyridoula-Lida Bitsi,Marinos Pitsikalis,Margarita Droulia

doi:10.3390/polym12020468

Spyridoula-Lida Bitsi, Marinos Pitsikalis + Show 1 more

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https://doi.org/10.3390/polym12020468

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Journal: Polymers	Publication Date: Feb 18, 2020
Citations: 3	License type: CC BY 4.0

Affiliation: National and Kapodistrian University of Athens

Abstract

Anionic polymerization techniques were employed for the synthesis of linear polystyrene (PS) and block copolymer of PS and polyisoprene (PI) PS-b-PI bearing end hydroxyl groups. Following suitable organic chemistry transformation, the –OH end groups were converted to moieties able to form complementary hydrogen bonds including 2,6-diaminopurine, Dap, thymine, Thy, and the so-called Hamilton receptor, Ham. The formation of hydrogen bonds was examined between the polymers PS-Dap and PS-b-PI-Thy, along with the polymers PS-Ham and PS-b-PI-Thy. The conditions under which supramolecular triblock copolymers are formed and the possibility to form aggregates were examined both in solution and in the solid state using a variety of techniques such as 1H-NMR spectroscopy, size exclusion chromatography (SEC), dilute solution viscometry, dynamic light scattering (DLS), thermogravimetric analysis (TGA), differential thermogravimetry (DTG), and differential scanning calorimetry (DSC).

Highlights

Polymer chemistry has witnessed a real explosion over recent decades
We report the synthesis of supramolecular block copolymers PSb -b-PI-b-PSa, where PS
The specific goals of this work are to establish efficient ways for the successful synthesis of the desired supramolecular block copolymers and to study the hierarchy of structures that are formed in solution, which starts from the formation of the pseudo triblock copolymer through the formation of hydrogen bonds between the complementary groups

Summary

Introduction

Polymer chemistry has witnessed a real explosion over recent decades. A variety of living/controlled polymerization techniques have emerged over the years, which allows for the synthesis of macromolecules with controlled molecular weights, molecular weight distributions, stereochemistry, end-group functionalization, optical properties, etc. [1,2,3,4,5,6,7,8,9,10]. An endless number of structures with numerous combinations of different polymer chains, topologies, and stereo-chemistries have emerged over the years, which shows that the macromolecular architecture can greatly affect the material properties both in solution and in the solid state [14,15,16,17,18,19]. All these studies have the common feature that the synthesized structures are based on stable covalent bonds. The stability of the double helix of DNA, molecular transportation, conformation, and, the biological activity of Polymers 2020, 12, 468; doi:10.3390/polym12020468 www.mdpi.com/journal/polymers

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