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Tasuku Nakajima Hidemitsu Furukawa Yoshimi Tanaka Takayuki Kurokawa Jian Ping Gong 《Journal of Polymer Science.Polymer Physics》2011,49(17):1246-1254
Introduction of soft filler in a hard body, which is one of the common toughening methods of hard polymeric materials, was applied for further toughening of robust double network (DN) hydrogels composed of poly(2‐acrylamido‐2‐methylpropanesulfonic acid) gels (PAMPS gels) as the first component and polyacrylamide (PAAm) as the second component. The fracture energy of the DN gels with the void structure (called void‐DN gels) became twice when the volume fraction of void was 1–3 vol % and the void diameter was much larger than the Flory radius of the PAAm chains. Such toughening was induced by wider range of internal fracture of the PAMPS network derived from partial stress concentration near void structure. Considering the mechanical tests and the dynamic light scattering results, it is implied that the absence of the load‐bearing PAAm structure inside the void is important for the toughening. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 49: 1246–1254, 2011 相似文献
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SUPER TOUGH GELS WITH A DOUBLE NETWORK STRUCTURE 总被引:1,自引:0,他引:1
Tasuku Nakajima Takayuki Kurokawa Hidemitsu Furukawa Yoshimi Tanaka Yoshihito Osada 龚剑萍 《高分子科学》2009,27(1)
Living tissues work with fantastic functions in soft and wet gel-like state.Thus,hydrogels have attracted much attention as excellent soft and wet materials,suitable tot making artificial organs for medical treatments.However, conventional hydrogels are mechanically too weak for practical uses.We have created double network (DN) hydrogels with extremely high mechanical strength in order to overcome this problem.DN gels are interpenetrating network (IPN) hydrogels consisting of rigid polyelectrolyte and s... 相似文献
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Chiba J Iimura S Yoneda Y Sugimoto Y Horiuchi T Muro F Ochiai Y Ogasawara T Tsubokawa M Iigou Y Takayama G Taira T Takata Y Yokoyama M Takashi T Nakayama A Machinaga N 《Chemical & pharmaceutical bulletin》2006,54(11):1515-1529
A novel series of benzoic acid derivatives as VLA-4 antagonists were synthesized. Optimization, focusing on activity and lipophilicity needed for cell permeability, resulted in the identification of 15b and 15e with good activity (IC50 = 1.6 nM each) and moderate lipophilicity (Log D = 2.0, 1.8). Furthermore, 15e demonstrated efficacy in murine asthma model by an oral dose of 30 mg/kg. 相似文献
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Yoshimi Zama Yoshibisa Okamoto Kaname Takagi Yoshihisa Kurasawa Atsushi Takada 《Journal of heterocyclic chemistry》1995,32(3):851-855
The title compound 4 was hydrolyzed to a new type of ynaminonitrile 5 and benzimidazolidines 7 and 9 under acidic or basic conditions. Reaction mechanisms were proposed. 相似文献
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