title: Determination of fracture energy of high strength double network hydrogels.
abstract: The fracture energy G of double network (DN) gels, consisting of poly(2-acrylamido-2-methylpropanesulfonic acid) (PAMPS) as the first network and poly(acrylamide) (PAAm) as the second network, was measured by the tearing test as a function of the crack velocity V. The following results were obtained: (i) The fracture energy G ranges from 10(2) to approximately 10(3) J/m2, which is 100-1000 times larger than that of normal PAAm gels (10(0) J/m2) or PAMPS gels (10(-1) J/m2) with similar polymer concentrations to the DN gels. (ii) G shows weak dependence on the crack velocity V. (iii) G at a given value of V increases with decreasing of cross-linking density of the 2nd network. The measured values of G were compared with three theories that describe different mechanisms enhancing the fracture energy of soft polymeric systems. A mechanism relating to a heterogeneous structure of the DN gel is convincing for the remarkable large values of G.
authors.affiliation: Creative Research Initiative Sousei (CRIS), Hokkaido University, Sapporo 001-0021, Japan.
authors.forename: Yoshimi
authors.initials: Y
authors.lastname: Tanaka
authors.forename: Rikimaru
authors.initials: R
authors.lastname: Kuwabara
authors.forename: Yang-Ho
authors.initials: YH
authors.lastname: Na
authors.forename: Takayuki
authors.initials: T
authors.lastname: Kurokawa
authors.forename: Jian Ping
authors.initials: JP
authors.lastname: Gong
authors.forename: Yoshihito
authors.initials: Y
authors.lastname: Osada
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry*; D018786:Bone Substitutes / Q000737:chemistry*; D020100:Hydrogels / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*; D013314:Stress, Mechanical; D013451:Sulfonic Acids / Q000737:chemistry*; D000099166:Polyacrylamides
chemical_list: D000180:Acrylic Resins; D018786:Bone Substitutes; D020100:Hydrogels; D011108:Polymers; D013451:Sulfonic Acids; D000099166:Polyacrylamides; C077118:poly(2-acrylamido-2-methyl-1-propanesulfonic acid)