STUDIA UBB CHEMIA, LX, 2, Tom I, 2015 (p. 169-176) (RECOMMENDED CITATION) THERMAL BEHAVIOUR OF POLYURETHANE MATRIX COMPOSITE MATERIALS ANCUŢA ELENA TIUC a,* , OVIDIU NEMEŞ a , IOANA PERHAIŢA b , HORAŢIU VERMEŞAN a , TIMEA GABOR a , VIOREL DAN a ABSTRACT. This paper describes the thermal behaviour of some composite materials, polyurethane foams reinforced with tire rubber waste and fir sawdust. According to experimental results, TG and DTG plots were drawn for finding the thermal stability domains, the partial and total weight loss and the temperature of the maximum weight loss. Composite materials have superior thermal stability of raw materials from which they were made. Increasing the percentage of polyurethane foam results in greater weight loss front of recycled rubber, but lower than fir sawdust and polyurethane foam. Keywords: thermal analysis, fir sawdust, polyurethane foam, recycled rubber INTRODUCTION Thermogravimetric analysis (TGA) is a thermal analysis technique which measures the amount and rate of change in the weight of a material as a function of temperature, in static rate or under a temperature program, in a controlled atmosphere. TGA technique is becoming increasingly used not only in determining the composition of materials but also to predict their thermal stability up to elevated temperatures. In TGA, typical weight loss profiles are analyzed for the amount or percent of weight loss at any given temperature, the amount or percent of non-combusted residue at final temperature, and the temperature of various degradation steps [1, 2]. In the last decade, the incorporation of reinforcements from natural resources such as jute, sisal, hemp, kenaf and wood fibers into polymeric materials to improve their performance has been widely studied [3–8]. a Technical University of Cluj-Napoca, Faculty of Materials and Environmental Engineering, 103-105 Muncii Ave, Cluj-Napoca, Romania. b “Raluca Ripan” Institute for Research in Chemistry, Babeş-Bolyai University, Cluj-Napoca, Romania. * Corresponding author Ancuta.TIUC@imadd.utcluj.ro