Study of thermal properties of intumescent additive Pentaerythritol phosphate alcohol Vijayakumar Sarannya • Palanichamy Sivasamy • Nagarajan David Mathan • Thangamani Rajkumar • Durairaj Ponraju • Chinnaswamy Thangavel Vijayakumar Received: 1 March 2010 / Accepted: 22 March 2010 / Published online: 8 April 2010 Ó Akade ´miai Kiado ´, Budapest, Hungary 2010 Abstract Bicyclic compounds containing phosphorus on their skeleton such as 2,4,6-trioxa-1-phosphabicy- clo[2,2,2]octane-4-methanol phosphate (PEPA) having three active ingredients required for intumescence have been synthesized. The structural characterization of PEPA was carried out by FT-IR, 1 H and 13 C NMR. The thermal behaviour of the material was studied using TGA, TGA– MS and pyrolysis GC–MS. Thermogravimetric analysis reveals that PEPA undergoes several stages of degradation with a char of about 12% at 800 °C. The TGA–MS studies indicate that the material degrades with the liberation of water, formaldehyde, alkene and alcohols as the major degradation products. Pyrolysis GC–MS results reveal that PEPA isomerizes in the acidic medium. PEPA and/or iso- mers of PEPA react with formaldehyde, one of the degra- dation products, to form cross-linked structure and cyclic products with the elimination of water molecule. The thermal degradation mechanisms for PEPA are presented and discussed. Keywords Intumescence Á Thermal degradation Á Thermogravimetry–mass spectrometry Á Pyrolysis GC–MS Á Degradation mechanism Introduction Today’s modern life increases the fire hazards, because of the development of electrical and electronic items and consumption of comfort items, etc. These are generally made up of petroleum products and having high energy content; therefore, they catch fire easily and release large amount of heat. The released heat helps the fire propaga- tion. This formed fire having secondary effect induces release of highly toxic corrosive gases and smoke. This secondary effect causes the unpredictable damages to materials and/or fire deaths. Combustion process is a complex phenomenon which comprises exothermic and endothermic reactions. Com- bustible materials cannot be made 100% non combustible. Combustibility of the material can be retarded by using flame retardants [1–3]. The causes of fire influence many researchers to develop fire-retardant materials. Fire retar- dants are chemicals which are added to combustible materials to make the material more resistant to fire by modifying pyrolysis reactions or oxidation reactions. Flame retardants interfere in the combustion of materials physically or chemically during heating, decomposition, ignition or flame spread [1, 4]. An ideal flame retardant should fulfil the appropriate mandatory fire requirements and rules, be easy to incorporate in the material involved, be compatible with the material involved, not alter the mechanical properties of the material, be colourless, have good light stability, be resistant towards ageing and hydrolysis, match and begin its thermal behaviour before the thermal decomposition of the material, should not cause corrosion, should not emit or at least emit low level of toxic gases, must not have harmful physiological and environmental effects, be commercially available and cost efficient. In flame-retardant-treated materials, the ignition V. Sarannya Á P. Sivasamy Post-graduate Department of Chemistry, Ayya Nadar Janaki Ammal College (Autonomous), Sivakasi 626124, India N. D. Mathan Á T. Rajkumar Á C. T. Vijayakumar (&) Department of Polymer Technology, Kamaraj College of Engineering and Technology, S.P.G.C. Nagar, K. Vellakulam Post, Virudhunagar 625701, India e-mail: ctvijay22@yahoo.com D. Ponraju Radiological Safety Division, Department of Atomic Energy, IGCAR, Kalpakkam 603102, India 123 J Therm Anal Calorim (2010) 102:1071–1077 DOI 10.1007/s10973-010-0768-y