Brush Architecture and Network Elasticity: Path to the Design of Mechanically Diverse Elastomers

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 (∼ n sc ), grafting density (∼ n g –1 ), and backbone degree of polymerization between cross-links ( n x ). This allowed experimental verification of theoretical scaling relationships between mechanical properties (shear modulus and strain-stiffening), architectural parameters [ n sc, n g, n x ], 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.