Beschreibung:
<jats:title>Abstract</jats:title><jats:p>Various processes taking place during the induction period of the change of a property accepted as a measure of the photostability, were investigated in polypropylene, PVC and EPDM rubber.</jats:p><jats:p>In polypropylene containing stabilizer, changes in stabilizer concentration and in molecular mass could be detected before the end of the induction period of the carbonyl formation. Kinetics and other characteristics of these changes depend on the type and amount of the stabilizers applied.</jats:p><jats:p>Hydrogen chloride evolution in UV‐irradiated PVC is accompanied also by carbonyl formation. In the presence of a metal soap stabilizer, carbonyl formation can be detected even during the induction period of hydrogen chloride evolution.</jats:p><jats:p>In case of EPOM rubber compounds, the study of thermal stability gives information about the changes in the first period of photodegradation when mechanical stability still remains unchanged.</jats:p>