Acceleration parameters for polycarbonate under blue LED photo-thermal aging conditions

Autor: James Edward Pickett, Christopher Luke Hein, Kaushal Gandhi, Rieko van Heerbeek
Rok vydání: 2019
Předmět:
Zdroj: Polymer Degradation and Stability. 164:69-74
ISSN: 0141-3910
Popis: Acceleration parameters have been determined for bisphenol A polycarbonate (PC) exposed to blue light emitting diodes (LED) in a commercial apparatus for testing optical components using absorbance at 360 nm as a proxy for yellowing. The effect of temperature in the range of 90–120 °C gave linear Arrhenius plots with activation energies of 30–48 kJ/mol, depending on the presence of stabilizers. Experiments at irradiances of 5–75 kW/m2 showed good reciprocity with the rate of degradation extrapolating to zero at zero irradiance. Parallel experiments using xenon arc irradiation with UV filters showed that the yellowing was proportional to the sample thickness up to at least 6 mm. The activation energies and thickness dependence are much different from the findings for PC outdoor weathering. Examples are shown for making service life predictions using these acceleration parameters.
Databáze: OpenAIRE