1 Thermal degradation of DNA, an all-in-one natural intumescent flame retardant Jenny Alongi 1 *, Alessandro Di Blasio 1 , John Milnes 2 , Giulio Malucelli 1 , Serge Bourbigot 3 , Baljinder Kandola 2 , Giovanni Camino 1 1 Dipartimento di Scienza Applicata e Tecnologia, Politecnico di Torino, sede di Alessandria, Viale Teresa Michel 5, 15121 Alessandria, Italy 2 Institute for Materials Research & Innovation, University of Bolton, Deane Road BL3 5AB, Bolton, United Kingdom 3 Unité Matériaux et Transformations (UMET) - CNRS UMR 8207, Equipe Ingénierie des Systèmes Polymères– Ecole Nationale Supérieure de Chimie de Lille BP 90108, F-59652 Villeneuve d’Ascq, France *Corresponding author: Tel/Fax: + 39 0131 229337 /+39 0131 229399; e-mail address: jenny.alongi@polito.it Abstract Very recently, deoxyribonucleic acid (DNA) has proven to be an efficient renewable, natural flame suppressant and retardant, due to its intrinsic intumescent features. In our previous work we have explored its flame retardant activity by applying as a surface coating on cotton fabrics and observed that on exposure to heat, the DNA was able to form a foamed char on the surface of the fabric. These remarkable results have stimulated this study on in-depth understanding of mechanism of thermal degradation of DNA. A number of characterization techniques have been exploited to investigate DNA decomposition, namely: thermogravimetry coupled to infrared spectroscopy or combined with differential thermal analysis, pyrolysis-combustion flow calorimetry and analysis of degradation residues. A scheme of DNA degradation mechanism is proposed to account for the results of the study. Keywords: Thermal degradation; TGA; TGA-IR; Pyrolysis-Combustion Flow Calorimeter; Intumescent flame retardants