Flame resistant performance of nanocomposites coated with exfoliated graphite nanoplatelets/carbon nanofiber hybrid nanopapers

SUMMARYExfoliated graphite nanoplatelets (xGnPs) were used to improve the flame resistant performance of glass fiber‐reinforced polyester composites. Along with xGnP, traditional intumescent fire retardant ammonium polyphosphate (APP) was introduced into the polymer matrix as the dominant additive to reduce the heat release rate (HRR) and total heat released (THR) of the composites. The cone calorimeter test results Indicate that the optimal weight ratios of xGnP and APP were 3% and 17% by weight, respectively. At such weight ratio, a synergistic effect between xGnP and APP was demonstrated. The flame resistant performance of the nanocomposites was further improved by applying xGnP‐dominant carbon nanofiber (CNF)/xGnP hybrid nanopaper onto the surface of the samples. Compared with the control sample, the integration of the HRR (THR) from 0 to 100 s of the sample coated with the nanopaper of CNF/xGnP = 1/3 shows more than 30% decrease in THR. Based on the results of mass loss, the nanopaper coating is also shown to enhance the structural stability of the samples under fire conditions, which affects the mechanical properties of the composites. The results show that the thermal properties, permeability of composites, and char formation play important roles in determining the fire behavior of the composites. Copyright © 2011 John Wiley & Sons, Ltd.