Additives such as processing agents, UV stabilizers, inhibitors against aging, flame retardants or inorganic fillers usually show a significantly different temperature behavior compared to the polymer matrix. This is why the content of additives as well as the filler-to-matrix ratio can often be determined with thermoanalytical techniques. Measurement examples will be introduced for determination and quantification of fillers and additives. Figure 1: Quantification of additives, polymer content and filler content (chalk) of a typical polymer part Although thermal analysis techniques do not detect particle size directly, measurement results are nevertheless influenced by the particle size and the quality of dispersion. The dehydration reaction of aluminum hydroxide (Al(OH)3), well known as flame retardant agent, will show the influence of particle size and dispersion performance on thermogravimetric data.