Blue glue: A new precursor of carbon aerogels

New carbon aerogels have been prepared from urea-branched phenol-resorcinol-formaldehyde resin. Such material, called blue glue and used as cold-set adhesive for wood, has been modified in order to obtain highly porous organic gels. The latter were prepared at different pH (5, 7 and 9), dried with supercritical methanol, and carbonised at two different heating rates (2.5 and 5 degrees C min(-1)). FTIR analysis confirmed the expected chemical structure of the gel, and GC-MS analysis of the solvent condensed after supercritical drying suggested a slight chemical degradation of the gels during the drying process. However, low-density (0.15-0.31 g cm(-3)), monolithic, carbon gels could be successfully derived from these materials, having high BET surface areas (900-1300 m(2) g(-1)) and high mesopore fractions (60-80%). These ranges of values originate from the conditions tested for preparing the materials. Such carbon aerogels are two times cheaper than their traditional resorcinol-formaldehyde-based counterparts and present similar, if not more developed, porous structures. (C) 2012 Elsevier Inc. All rights reserved.