Search for: modified-clays
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    Mechanical properties and structure of solvent processed novolac resin/layered silicate: Development of interphase region

    , Article RSC Advances ; Volume 5, Issue 98 , Jun , 2015 , Pages 80875-80883 ; 20462069 (ISSN) Jahanmard, P ; Shojaei, A ; Sharif University of Technology
    Royal Society of Chemistry  2015
    Composites of phenol-formaldehyde (PF) resin with Closite Na+ and Closite 30B up to 20 wt% loadings were prepared by solution mixing. Tensile testing showed that both pristine and organically modified clays increased considerably the mechanical properties of PF resin at 2.5 wt% loading followed by marginal improvement or even sacrificed properties at high loadings. DMA and DSC analyses suggested development of a highly crosslinked and well adhered interphase around silicate layers. A novel three-phase model considering the interphase region was proposed to predict composite modulus. The model was successfully employed to correlate morphological characteristics and mechanical properties of... 

    Antipolyelectrolyte superabsorbing nanocomposites: synthesis and properties

    , Article Journal of Applied Polymer Science ; Volume 114, Issue 6 , 2009 , Pages 3542-3547 ; 00218995 (ISSN) Pourjavadi, A ; Kheirabadi, M ; Zohuriaan Mehr, M. J ; Kabiri, K ; Sharif University of Technology
    Novel polyampholytic superabsorbing nanocomposites based on the zwitterionic sulfobetaine monomer [3-(methacrylamido)propyl)]dimethyl(3- sulfopropyl)ammonium hydroxide were synthesized through in situ polymerization in aqueous solution with different contents of an organo-modified clay (OMMT, Cloisite 30B). Structural and thermomechanical properties of hydrogels were characterized by FT-IR, XRD, and DMTA, respectively. Swollen gel strength of hydrogels was determined by a rheological method. Storage modulus of the hydrogels was considerably improved in comparison with its the clay-free counterpart. The nanocomposite hydrogel containing 15% OMMT possessed the highest gel strength. The glass... 

    Anomalous fracture behavior in an epoxy-based hybrid composite

    , Article Materials Science and Engineering A ; Volume 515, Issue 1-2 , 2009 , Pages 49-58 ; 09215093 (ISSN) Marouf, B. T ; Pearson, R. A ; Bagheri, R ; Sharif University of Technology
    In this investigation, core-shell rubber particles and organically modified clay were added to an epoxy resin and the changes in mechanical behavior were studied. As expected, the yield strength of the organoclay-filled epoxies increased modestly with increasing clay content and the yield strength of the rubber-modified compounds decreased with rubber content. Interestingly, the compressive yield strength of epoxy resins containing both rubber particles and organoclay (a.k.a. hybrid nanocomposites) was found to be independent on organoclay content (up to 5 phr). The fracture toughness of organoclay-filled epoxies increased modestly with clay content and, as expected, the increases in...