Open AccessNanocomposite hydrogels: Fracture toughness and energy dissipation mechanisms
Author(s) -
Klein Andrea,
Whitten Philip G.,
Resch Katharina,
Pinter Gerald
Publication year - 2015
Publication title -
journal of polymer science part b: polymer physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.65
H-Index - 145
eISSN - 1099-0488
pISSN - 0887-6266
DOI - 10.1002/polb.23912
Subject(s) - self healing hydrogels , materials science , nanocomposite , hectorite , composite material , exfoliation joint , toughness , viscoelasticity , dissipation , polymer chemistry , nanotechnology , montmorillonite , graphene , physics , thermodynamics
In this study, fracture toughness of nanocomposite hydrogels is quantified, and active mechanisms for dissipation of energy of nanocomposite hydrogels are ascertained. Poly( N , N ‐dimethylacrylamide) nanocomposite hydrogels are prepared by in situ free radical polymerization with the incorporation of Laponite, a hectorite synthetic clay. Transmission electron microscopy proves exfoliation of clay platelets that serve as multifunctional crosslinkers in the created physical network. Extraordinary high fracture energies of up to 6800 J m −2 are determined by the pure shear test approach, which shows that these soft and stretchable hydrogels are insensitive to notches. In contrast to single‐ and double‐network hydrogels, dynamic mechanic analysis and stress relaxation experiments clarify that significant viscoelastic dissipation occurs during deformation of nanocomposite hydrogels. Similar to double‐network hydrogels, crack tip blunting and plastic deformation also contribute to the observed massive fracture energies. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2015 , 53 , 1763–1773