Abstract
Novel phosphonium-type organoclays having several kinds of the chemical structures were designed and synthesized, and then epoxy/clay nanocomposites were obtained with these organoclays as their catalysts, respectively. The thermal properties and the adhesive strength were investigated, and the structures and morphologies of the epoxy/clay nanocomposites were evaluated by transmission electron microscopy (TEM). Consequently, the incorporation of organoclays with different side chains in phosphonium cations into the epoxy matrix led to different morphologies of the organoclay particles, and then the distribution changes of silicate layers in the epoxy resin influenced the physical properties of the nanocomposites. When phosphonium organoclay introduced with carboxy group were adopted, it was found that clay particles were well dispersed and exfoliated. The epoxy/clay nanocomposite realized the high glass transition temperature (Tg) and low coefficient of thermal expansion (CTE) in epoxy/clay nanocomposite were observed in comparison with those of neat epoxy resin. On the other hand, in the case of phosphonium organoclay introduced with alkyl group, it was found that the dispersion states of clay particles were intercalated but not exfoliated. The intercalated clay did not influence the Tg and CTE of the nanocomposite.
