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Sepiolite‐reinforced epoxy nanocomposites: Thermal, mechanical, and morphological behavior
Author(s) -
Nohales Andrés,
MuñozEspí Rafael,
Félix Paula,
Gómez Clara M.
Publication year - 2010
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.32797
Subject(s) - sepiolite , materials science , flexural strength , epoxy , thermogravimetric analysis , composite material , nanocomposite , dynamic mechanical analysis , flexural modulus , curing (chemistry) , thermal stability , polymer , chemical engineering , chemistry , organic chemistry , engineering , raw material
Abstract A bisphenol A‐based epoxy resin was modified with pristine sepiolite and an organically surface‐modified sepiolite and thermally cured using two different curing agents: an aliphatic and a cycloaromatic diamine. The nanocomposites were characterized by dynamic mechanical analysis (DMA), rheology, thermogravimetric analysis (TGA), and electron microscopy. The initial sepiolite–epoxy mixtures show a better dispersion for the sepiolite‐modified system that forms a percolation network structure. Mechanical properties have also been determined. The flexural modulus of the epoxy matrix slightly increases by the incorporation of the organophilic sepiolite. The flexural strength of the sepiolite‐modified resin cured with the aliphatic diamine increased by 10%, while the sepiolite‐modified resin cured with the cycloaromatic diamine resulted in a lower flexural strength, as compared with the unmodified resin. Electron micrographs revealed a better nanodispersion of the sepiolite in the epoxy matrix for the organophilic modified sepiolite nanocomposite. The initial thermal decomposition temperature did not change significantly with the addition of sepiolite, whereas mechanical properties were affected. The reduced flexural strength was attributed to the stress concentrations caused by the sepiolite modifier. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011