Table 1: Composition by weight of classic and formaldehyde-free tannin based rigid foams.

ChemicalsClassic TBRFs (%)
Room temperature
Formaldehyde-free TBRFs (%)
Hot press at 120°C

Mimosa tannin47.752.6
Furfuryl alcohol16.713.1
Formaldehyde4.3
Blowing agent4.83.5
Acid catalyst12.45.8
Water14.125.0