Thermochimica Acta 547 (2012) 76–82 Contents lists available at SciVerse ScienceDirect Thermochimica Acta jo u r n al hom ep age: www.elsevier.com/locate/tca The effect of some wood preservatives on the thermal degradation of Scots pine Eylem D. Tomak a,∗ , Ergun Baysal b , Huseyin Peker c a Karadeniz Technical University, Faculty of Forestry, Forest Industrial Engineering Department, 61080 Trabzon, Turkey b Mugla University, Faculty of Technology, Department of Wood Science and Technology, Kotekli, 48000 Mugla, Turkey c Artvin Coruh University, Faculty of Forestry, Forest Industrial Engineering Department, 06100 Artvin, Turkey a r t i c l e i n f o Article history: Received 12 March 2012 Received in revised form 1 June 2012 Accepted 6 August 2012 Available online xxx Keywords: Boron compounds Fire retardancy Scots pine TGA Weight loss a b s t r a c t Wood has been a structural material for many years; however, its ability to burn has limited its use in some applications. This study aims to evaluate the effect of commercial wood preservatives having concentration of 4% on the thermal behavior of Scots pine wood, and compare the fire retardant effective- ness of these preservatives with that of boron compounds. Thermal degradation of treated and untreated wood samples was evaluated by thermogravimetry (TG), differential thermogravimetry (DTG) and dif- ferential thermal analysis (DTA). Thermal behavior of treated wood differed from thermal behavior of untreated wood in terms of a high char yield. Results showed that weight loss of wood reduced while char yield increased in the charring phase of the pyrolysis in the boron containing preservative treated wood accompanying with pyrolysis temperature lowered. The highest char yield was obtained from the samples treated with disodium octaborate tetrahydrate in the all treated groups. © 2012 Elsevier B.V. All rights reserved. 1. Introduction Wood is one of the most widely used construction materials due to being unique renewable and environmental friendly natural resources. With its easy processing, physical and mechanical prop- erties, aesthetic appearance, environmental and health aspects, there is a growing interest to use wood and wood based compos- ites for applications in building construction [1–3]. However, wood and wood composites being a carbon based cellulosic material can easily burn when subjected to flame source or direct heat in suit- able conditions [4]. This disadvantage limits its applications and also causes some restrictions. In Japan, high fire retardant efficiency is needed for building materials by Building Standard Law [5]. As being a combustible material, the fire retardant (FR) treatments and chemicals are very important for wood in construction, and have attracted more attentions than even before. For this reason, predicting the models for thermal degradation of untreated and impregnated wood is essential [1,2]. Various methods have been developed for evaluating the effectiveness of fire retardant treated wood such as thermal analysis, tunnel flame-spread tests, critical oxygen index tests, smoke production tests, fire tube test, cone calorimeter, heat release rate, toxicity and analysis of solid residue or gaseous products of thermal decomposition [3,6–8]. Among these methods, thermal analysis (differential scanning calorimetry ∗ Corresponding author. Tel.: +90 4623772847; fax: +90 4623257499. E-mail addresses: eylemdizman@yahoo.com (E.D. Tomak), bergun@mu.edu.tr (E. Baysal), peker100@hotmail.com (H. Peker). and thermogravimetry) is a simple, convenient and fast method for evaluating the pyrolysis and flame retardants under air or inert gas flow [7]. The combustion performance of wood related to the reac- tion mechanism and pyrolysis products during the heat-flow. The mechanism of fire retardant efficiency can be well understood by studying the pyrolysis process of wood treated with fire retardants [9]. Using the fire retardant chemicals can cause pyrolysis reactions to form more char and water, and therefore reduce the temperature of the pyrolysis as well as reduce the yield of the flammable gases. The chemicals can also cause a reduction on the effective heat of combustion, heat release and flame spread [8,9]. Improved effect of fire retardant chemicals on combustion and thermal degradation of wood and wood based composite products was reported by a num- ber of researchers [1,3–5,8,10–23]. Shafizadeh [24] investigated 21 different fire retardants, and found phosphoric acid was the most effective one in reducing the amount of volatiles and in increasing the amount of residual char, followed by mono and diammonium phosphate, and zinc chloride. The fire retardant formulations used for wood protection gen- erally contain boron, nitrogen and phosphorus [25]. Boron being one of the main components of most fire retardant formulations has been used in wood preservation industry for many years [26]. The fire retardant effectiveness of boron compounds is a physical mechanism achieved by the formation of a coating or protective layer on the wood surface at high temperature, and by forming glassy films that may inhibit mass transfer of combustible gases [8,26]. Apart from being an environmental friendly fire retardant chemical, boron compounds are very effective against to wood 0040-6031/$ – see front matter © 2012 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.tca.2012.08.007