Nanotube-reinforced tannin/furanic rigid foams

Abstract

Tannin/furanic foams compressive strength and impact resistance are improved by addition of small percentages of multiwall carbon nanotubes after sonication of the mixture of components before blowing of the foam. These improvements although clear are limited by the limited proportion of nanotubes that can be added to the foam, higher proportions causing unhandable increases in viscosity of the blowing mixture. Scanning electron microscopy examination at high magnification of the nanotube filled foams showed an even distribution of the nanotubes imbedded in the foam cell walls in certain zones but an apparent lack of nanotubes in other cell wall zones.