Brush Architecture and Network Elasticity: Path to the Design of Mechanically Diverse Elastomers
Mitchell Maw, Benjamin J. Morgan, Erfan Dashtimoghadam, Yuan Tian, Egor A. Bersenev, Alina V. Maryasevskaya, Dimitri A. Ivanov, Krzysztof Matyjaszewski, Andrey V. Dobrynin, Sergei S. Sheiko
Abstract
We unveil universal correlations between architectural parameters and nonlinear elastic properties of brush polymer networks. A comprehensive library of poly(n-butyl acrylate), poly(dimethylsiloxane), and polyisobutylene brush networks was synthesized with systematically varied side chain length (∼nsc), grafting density (∼ng–1), and backbone degree of polymerization between cross-links (nx). This allowed experimental verification of theoretical scaling relationships between mechanical properties (shear modulus and strain-stiffening), architectural parameters [nsc, ng, nx], and microstructure from in situ small-angle X-ray scattering in both comb and bottlebrush conformational regimes. These results can be used as a foundation for the programmable design of mechanically diverse solvent-free elastic materials.