Characterization of physical and chemical aging of polymeric solar materials by mechanical testing

While significant chemical aging was detected for PPE + PS, indicated by a significant drop in strain-to-break values even after 2000 h of aging exposure, no clear conclusion could be drawn for PEX-1, partially due to the large data scatter observed for this material. In any case, when comparing strain values deduced from optical techniques and crosshead displacement measurements, the former are to be preferred due to the higher accuracy.