Studies on thermal degradation and flame retardant behavior of the sisal fiber reinforced unsaturated polyester toughened epoxy nanocomposites

Abstract

ABSTRACTUnsaturated polyester (UP) toughened nanocomposites were prepared using both sisal fibers and montmorillonite clays. The effect of fibers and Cloisite 30B (C30B) nanoclays on the mechanical properties, thermal stability, flame retardant, and morphological behavior of the UP toughened epoxy (Epoxy/UP) were systematically studied. The chemical structures of Epoxy, UP, and Epoxy/UP systems were characterized using Proton Nuclear magnetic resonance (1HNMR) and Fourier transform infrared (FTIR) spectra. The homogeneous dispersion of nanoclay within the polymer matrix was analyzed using transmission electron microscopy (TEM) and X‐ray diffraction (XRD) analysis. Incorporation of sisal fibers and C30B nanoclays within Epoxy/UP system resulted in an increase in the mechanical, thermal, and flame retardance properties. Thermogravimetric analysis (TGA) has been employed to evaluate the thermal degradation kinetic parameters of the composites using Kissinger and Flynn‐Wall‐Ozawa methods. Cone calorimeter, UL‐94, and LOI tests revealed a reduction in the burning rate of the matrix with the addition of fibers and nanoclays. The results showed that the treated fiber reinforced nanocomposites had higher thermal stability and better flame retardant properties than the treated fiber reinforced composites. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42068.