Abstract
PEHD plastic materials are more and more used in applications. Their possible physical and chemical changes, depending on the temperature changes and time, in a given atmosphere, can be made by simultaneous measurement of the sample mass and its temperature. It is achieved by the use of thermogravimetry (TG). The thermogravimeter Mettler Toledo presents thermograms or thermogravimetric curves as well as their differentials. Results obtained in this way can be starting points for next researches. Keywords: PEHD, thermogravimetry, thermogravimetric differentials, quantitative analysis