Effects of aramid honeycomb core on the flame retardance and mechanical property for isocyanate‐based polyimide foams

Abstract

ABSTRACTIn this work, composite materials containing aramid honeycomb core (ARHC) reinforced isocyanate‐based polyimide foams (IBPIFs) were prepared by a simple free‐foaming process. The flame retardance, smoke performance, and mechanical property of the composite materials along the transverse (W) and longitude (L) directions of ARHC were studied. Results of limiting oxygen index and cone calorimeter reveal that the space partition action of ARHC on IBPIFs, barrier action of honeycomb structure on fire, and generation of straight, flurry and porous char layer in the honeycomb cells during combustion effectively enhanced the flame retardance of IBPIFs. Mechanical property test shows that IBPIFs and ARHC presented a positive synergetic effect, and ARHC increased the compression strength of IBPIFs along the W and L directions of ARHC by approximately 300%. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45041.