Matrix‐assisted laser desorption/ionization time‐of‐flight structure determination of complex thermoset networks: Polyflavonoid tannin–furanic rigid foams

Polyflavonoid tannin–formaldehyde–furfuryl alcohol rigid foams yield hardened, rigid, tridimensional networks in which there are covalently linked structures derived from the reaction of their main components. Thus, polyflavonoid tannin structures, tannin–formaldehyde structures, furanic structures derived by the self‐condensation of furfuryl alcohol, and mixed tannin–furane and tannin–furane–formaldehyde structures are all present in the continuous foam networks. Some complex, tridimensional structures involving tannin's flavonoid units, furan nuclei, and formaldehyde‐derived methylene bridges appear to be formed too. Matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry has been used to determine the different segments contributing to forming the complex thermosetting networks of the hardened foams.