Preparation and Flame Resistance Properties of Revolutionary Self-Extinguishing Epoxy Nanocomposites Based on Layered Double Hydroxides
Mauro Zammarano, Massimiliano Franceschi, S Bellayer, Jeffrey W. Gilman, Sergio Meriani
Layered double hydroxides/epoxy nanocomposites (LDHs/EP) were prepared from organo modified LDHs, a diglycidyl ether of bisphenol A monomer (DGEBA) and amine curing agents. The organomodified LDHs were obtained by ionic exchange of a magnesium-aluminum carbonate LDH in an acid medium. The replacement of inorganic carbonate anions with organic ones increased the hydrophobicity of the clay allowing the diffusion of the epoxy resin between the inorganic-organic lamellae. X-ray diffraction and transmission electron microscopy showed a dispersion of the layers at a nanometer scale, indicating the formation of a LDH/EP nanocomposite. The thermal degradation and flame resistance properties of LDH/EP nanocomposites, montmorillonite-epoxy nanocomposites (MMT/EP), LDH/EP microcomposites and aluminum hydroxide-epoxy microcomposites were compared by thermogravimetrical analyses, simultaneous thermal analyses, UL94 and cone calorimeter tests. Only LDH/EP nanocomposites showed self-extinguishing behavior in the horizontal UL94 test; LDH/EP microcomposites and MMT/EP nanocomposites samples burned completely showing that the unique flame resistance of LDH/EP nanocomposites is related to both the level of dispersion and the intrinsic properties of LDH clay. Furthermore, cone calorimeter revealed intumescent behavior for LDH/EP nanocomposites and a higher reduction in the peak heat release rate compared to montmorillonite-epoxy nanocomposites.
, Franceschi, M.
, Bellayer, S.
, Gilman, J.
and Meriani, S.
Preparation and Flame Resistance Properties of Revolutionary Self-Extinguishing Epoxy Nanocomposites Based on Layered Double Hydroxides, Polymer Journal, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=861349
(Accessed December 2, 2023)