Solvent-free, supersoft and superelastic bottlebrush melts and networks

• Published in: Nature materials 2016-02, Vol.15 (2), p.183-189
• Main Authors: Daniel, William F. M., Burdyńska, Joanna, Vatankhah-Varnoosfaderani, Mohammad, Matyjaszewski, Krzysztof, Paturej, Jarosław, Rubinstein, Michael, Dobrynin, Andrey V., Sheiko, Sergei S.
• Format: Article
• Language: English
• Subjects: 639/301/923/1028; 639/638/455/303; Biomaterials; Chains (polymeric); Condensed Matter Physics; Elasticity; Elastomers; Evaporation; Gels; letter; Materials Science; Melts; Modulus of elasticity; Nanotechnology; Networks; Optical and Electronic Materials; Polymers; Solvents; Stiffness; Superelasticity
• ISSN: 1476-1122; 1476-4660
• DOI: 10.1038/nmat4508

Solvent-free, supersoft and superelastic polymer melts and networks made from bottlebrush macromolecules can display low modulus, high strain at break, and extraordinary elasticity. Polymer gels are the only viable class of synthetic materials with a Young’s modulus below 100 kPa conforming to biological applications 1 , 2 , 3 , yet those gel properties require a solvent fraction 4 , 5 , 6 , 7 . The presence of a solvent can lead to phase separation, evaporation and leakage on deformation, diminishing gel elasticity and eliciting inflammatory responses in any surrounding tissues. Here, we report solvent-free, supersoft and superelastic polymer melts and networks prepared from bottlebrush macromolecules. The brush-like architecture expands the diameter of the polymer chains, diluting their entanglements without markedly increasing stiffness. This adjustable interplay between chain diameter and stiffness makes it possible to tailor the network’s elastic modulus and extensibility without the complications associated with a swollen gel. The bottlebrush melts and elastomers exhibit an unprecedented combination of low modulus (∼100 Pa), high strain at break (∼1,000%), and extraordinary elasticity, properties that are on par with those of designer gels 8 , 9 .