Glycerol, a by-product from biodiesel production can react with di-carboxylic organic acids, resulting in polyesters, and can be used in the composition of urea/formaldehyde or phenol/formaldehyde resins to improve the qualities of adhesion and moisture resistance of them. In this work, six kinds of resins derived from glycerol, named as GAA (glycerol/adipic acid), GAAU (glycerol/adipic acid/urea), GAF (glycerol/phtalic acid), GU (glycerol/urea), GUF (glycerol/urea/formaldehyde) and GF (glycerol/formaldehyde), were synthesized. The resins derived from carboxylic acids had better thermal stability (up to 350 ºC) than those derived from formaldehyde (up to 200 ºC). The average molecular weights of the resins were determined by matrix assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) and gel-permeation chromatography (GPC), and are in the range of 1800-2800 Da, being oligomers, and the polydispersity indexes are in the range of 1.3 to 1.8. The ¹H and 13C nuclear magnetic resonance (NMR) techniques were used to identify the structure of the resins.
glycerol; resins; biodiesel
