Carbonisation of polyflavonoid tannineformaldehydeefurfuryl alcohol rigid foams yields a three-dimensional network in which polynuclear aromatic hydrocarbon chains of high molecular weight are also covalently linked to some furan resin structures surviving carbonisation. Struc- ture conservation on carbonising extends to furanic structures derived by the self-condensation of furfuryl alcohol which are integral part of the total network. Some complex, three-dimensional structures derived by the rearrangement to polyaromatic hydrocarbons of polyflavonoid tannins, constituted of aromatic benzene and furan rings, and some formaldehyde-derived methylene bridges appear to be formed. The fragments observed are fragments of the continuous network formed and converted by carbonisation. MALDI-TOF appears to be a suitable method for examining oligomer residues present in carbonised complex polycondensation polymer networks and it appears to be capable of determining aspects of the structure and characteristics of complex solids which are too difficult to determine by other techniques.