Preparation and properties of effective epoxy/clay nanocomposites with exfoliated reactive flame retardant clay

POLY 196

Wei Sheng Wang, u4566@ms3.hinet.net, Yi Wen Wu, Hong Syu Chen, and YW Chen-Yang, yuiwhei@cycu.edu.tw. Department of Chemistry and Center for Nanotechnology, Chung Yuan Christian University, 200, Chungbei Rd., Chungli City, Taoyuan County 320, Taiwan, Chungli, 320, Taiwan
In this study, a reactive flame retardant montmorillonite clay (RFC) was synthesized by modification of a sodium montmorillonite clay (MMT) with a flame retardant phosphonium salt via the ion exchange reaction and further surface functionalization by grafting with an epoxide group-containing silane. Various amounts of RFC were then added to the epoxy resin and thermally cured to form a series of the effective epoxy/RFC nanocomposites (EP/RFCx). The microstructure, thermal property and flame retardant property of the as-prepared EP/RFCx are characterized by a combination of X-ray diffraction (XRD), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA) and limiting oxygen index (LOI), respectively. The results reveal that the as-prepared reactive clay is highly exfoliated and uniformly dispersed in the epoxy matrix, due to the possible participation of the epoxide groups of silane modifiers in the curing process. It is also found that the thermal stabilities of the composites are significantly improved, compared to that of the neat epoxy. Besides, the storage modulus and the glass transition temperature of the nanocomposite steadily increased with increasing the RFC loading. Furthermore, the LOI values indicated that the as-prepared composites are flame retardant even with 1wt% of RFC.