ISSN impresa 0717-3644 ISSN online 0718-221X Maderas. Ciencia y tecnología 2021 (23): 46, 1-10 DOI: 10.4067/s0718-221x2021000100446 1 KINETIC ANALYSIS OF THERMAL DEGRADATION OF Cedrela odorata, Marmaroxylon racemosum AND Tectona grandis FROM TIMBER INDUSTRY Camily Daiane Cavinato 1 Matheus Poletto 2,♠ https://orcid.org/0000-0003-2317-2713 ABSTRACT Thermal analysis is a powerful tool to predict the composition and thermal stability of diferent materials. In this work, thermogravimetric analysis of Cedrela odorata, Marmaroxylon racemosum and Tectona grandis was carried out at four diferent heating rates (5 °C·min -1 , 10 °C·min -1 , 20 °C·min -1 and 40 °C·min -1 ) in a non-isothermal condition. The degradation kinetics was evaluated based on Flynn-Wall-Ozawa and Criado methods. The half-life time of wood degradation reaction was also studied. The wood thermal degradation pro- cess in an oxidizing atmosphere can be divided in dehydration, devolatilization, and combustion. The kinetic results revels apparent activation energy values of 130-240 kJ·mol -1 for Tectona grandis, 150-191 kJ·mol -1 for Marmaroxylon racemosum and 188-205 kJ·mol -1 for Cedrela odorata, when conversion values ranged from 0,1-0,5. The most probable degradation mechanism for wood species studied is a difusion model based on a three-dimensional difusion. Cedrela odorata presented the lowest reaction half-life time while Marmaroxylon racemosum showed the highest. On the basis of these results, it can be concluded that Flynn-Wall-Ozawa and Criado methods associated with half-life time of reaction may contribute to better understand the wood degra- dation before use it in polymer composites. Keywords: Activation energy, Criado method, Flynn-Wall-Ozawa, thermogravimetry, thermal stability. INTRODUCTION The concern of society with environmental issues is a driving force that constantly seeks that new alter- native in diferent industry sectors can minimize waste generation and promote recycling initiatives that can contribute to obtain sustainable processes (Barbos et al. 2020, Gheith et al. 2019).The forestry sector is known for using natural resources on a large scale and for generating large amounts of wood waste (Mohd Yusof et al. 2020). The main part of these lignocellulosic residues is commonly used for energy generation (Poletto 2017) but some are disposed of in landflls. In Brazil, it is estimated that about 30 million tons of wood waste are generated annually (Ramos et al. 2018). The timber industries are responsible for 91 % of this annual genera- tion (Ramos et al. 2018). In the Brazilian Amazon Region, it is estimated that more than 8 million cubic meters of wood waste are generated annually (Ramos et al. 2018). In addition, 59 % of native wood is lost until value added wood products can be obtained (Batista et al. 2015). The possibility of reusing or recycling this lignocellulosic waste to be used in the sector itself or, to be used as reinforcement in composite materials are interesting alternatives both from a fnancial and environmental point of view (Adhikary et al. 2008, AlMaadeed et al. 2014). 1 University of Caxias do Sul (UCS), Chemical Engineering, Caxias do Sul, Brazil. 2 University of Caxias do Sul (UCS), Postgraduate Program in Engineering of Processes and Technologies (PGEPROTEC), Caxias do Sul, Brazil. ♠ Corresponding author: mpolett1@ucs.br Received:03.01.2021 Accepted:15.04.2021