The degradation temperatures at 10 and 50 % mass loss (T10 % and T50 %) after various periods of photodegradation were selected as reference indexes. An additional parameter (DT),
The degradationtemperatures at 10 and 50 % mass loss (T10 % and T50 %)after various periods of photodegradation were selected asreference indexes. An additional parameter (DT),