Spherical polymer brushes, poly(acrylic acid) (PAA)-grafted polystyrene nanoparticle (PAA@PS), are employed as the macro-crosslinker to prepare PAA hydrogels. Benefitting from the innumerable hydrogen bonds between highly entangled PAA chains both in bulk and on the polymer brush, the PAA/PAA@PS hydrogels combine desirable stretchability, toughness, and notch-insensitivity. The uniaxial tensile tests show a very high fracture elongation up to 9.1 × 103 % while the fracture toughness reaches 3.0 MJ m-3 and the maximum swelling ratio of the hydrogel can be 2.0 × 103 as well. After being loaded with silver nanoparticles, the PAA/PAA@PS hydrogels are employed as a recyclable catalyst successfully.
Keywords: hydrogen bonds; notch-insensitivity; spherical polymer brushes; tough hydrogels.
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