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Environmental effects on the adhesion properties of nanostructured epoxy‐silica hybrids
Author(s) -
Lionetto Francesca,
Frigione Mariaenrica
Publication year - 2015
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.42514
Subject(s) - epoxy , adhesive , materials science , composite material , curing (chemistry) , thermosetting polymer , hybrid material , flexural strength , nanotechnology , layer (electronics)
ABSTRACT A nanostructured epoxy‐silica hybrid based on epoxy systems with interpenetrating silica domains was designed for a possible use as a structural adhesive for civil engineering applications. Silica domains were obtained in situ during the curing of the thermosetting matrix by means of the sol‐gel process, which was able to chemically bind the organic phase with the inorganic one. To assess the ability of the developed epoxy‐silica hybrid system of overcoming some of the well known deficiencies of conventional epoxy adhesives used in civil engineering field, the environmental effects on the adhesion properties of these novel systems were investigated. First, flexural tests were undertaken on cast epoxy‐silica specimens to determine the mechanical properties of the nanostructured adhesive when exposed to different environmental conditions, that is, moderate temperature or immersion in water. For comparison purposes, a control sample of epoxy resin, representative of a commercially available adhesive, was tested after the same exposure regimes. In order to assess their durability in service, concrete/concrete joints, bonded or with the hybrid epoxy‐silica or with the control epoxy adhesive, were exposed to the same environmental conditions and subjected to adhesion tests according to the “slant shear test.” The results obtained on both cast specimens and concrete/concrete adhesive joints proved the significantly better retention of properties of the nanostructured organic–inorganic adhesive compared to the control resin after exposure to moderate temperature or immersion in water. This constitutes a distinct advantage of the hybrid system over the corresponding conventional epoxy resins cured at ambient temperature for civil engineering applications. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132 , 42514.