Pine tannin-based rigid foams: Mechanical and thermal properties

Pine bark tannin foams were prepared for the first time. The high reactivity of pine tannins in relation to other tannins induced the change in the tannin foam formulations in order to coordinate foam resin hardening, reaction exotherm and solvent blowing allowing the formation of a rigid foam. Pine tannin foams with and without formaldehyde were prepared. Their characteristics were tested as regards stress–strain curves, thermal conductivity, Young's modulus, compression strength, densification, densification rate and energy absorbed under compression. Mostly, properties the pine tannin foams with formaldehyde have properties similar to mimosa tannin foams, in some cases slightly lower and in others slightly higher. Pine tannin foams without formaldehyde showed lower mechanical strength and more elastic behaviour.

Pine bark tannin foams were prepared for the first time. The high reactivity of pine tannins in relation to other tannins induced the change in the tannin foam formulations in order to coordinate foam resin hardening, reaction exotherm and solvent blowing allowing the formation of a rigid foam. Pine tannin foams with and without formaldehyde were prepared. Their characteristics were tested as regards stress–strain curves, thermal conductivity, Young's modulus, compression strength, densification, densification rate and energy absorbed under compression. Mostly, properties the pine tannin foams with formaldehyde have properties similar to mimosa tannin foams, in some cases slightly lower and in others slightly higher. Pine tannin foams without formaldehyde showed lower mechanical strength and more elastic behaviour.Figure optionsDownload as PowerPoint slideHighlights
► Pine bark tannin foams were prepared with and without formaldehyde for the first time.
► High reactivity tannin induced change in foam formulations to coordinate foam resin hardening, reaction exotherm and solvent blowing.
► Stress–strain curves, thermal conductivity, E-modulus, compression strength and energy adsorbed, densification and its rate, were tested.
► Pine tannin foams have properties similar to mimosa tannin foams.
► Pine tannin foams without formaldehyde showed lower mechanical strength and more elastic behaviour.