Self-assembly in solution of a reversible comb-shaped supramolecular polymer

TL;DR

This paper presents a novel reversible comb-shaped supramolecular polymer that self-assembles via hydrogen bonding, with tunable backbone length influenced by solvent, concentration, temperature, and side-chain bulkiness.

Contribution

It introduces a new method for synthesizing a reversible, self-assembling supramolecular polymer with controllable structure and properties.

Findings

Backbone length can be tuned by solvent, concentration, and temperature.

Bulkiness of side-chains significantly affects self-assembly and backbone length.

Arm density can be reduced by mixing with low molar mass bis-urea.

Abstract

We report a single step synthesis of a polyisobutene with a bis-urea moiety in the middle of the chain. In low polarity solvents, this polymer self-assembles by hydrogen bonding to form a combshaped polymer with a central hydrogen bonded backbone and polyisobutene arms. The comb backbone can be reversibly broken, and consequently, its length can be tuned by changing the solvent, the concentration or the temperature. Moreover, we have proved that the bulkiness of the side-chains have a strong influence on both the self-assembly pattern and the length of the backbone. Finally, the density of arms can be reduced, by simply mixing with a low molar mass bis-urea.