Within this work a basic characterization of amorphous and semi-crystalline polymer films (polyphenylene ether (PPO), polycarbonate (PC), polypropylene (PP), polyamide 12 (PA12) and crosslinked polyethylene (PE-X)) for solar absorbers was carried out. As to the analytical characterization, IR- and UV/VIS/NIR-spectroscopy, dynamic mechanical analysis (DMA) and differential scanning calorimetry (DSC) was used. The technological properties specific heat capacity and thermal conductivity were determined using various thermo-analytical methods. IR- and UV/VIS/NIR-spectroscopy showed that the investigated PPO grades are modified by polystyrene or polyamide 66 and that in all polymer grades UV-stabilizers are added. Compared to black-coloured PPO grades for black-coloured polyamide 12 a higher solar absorption was obtained, which can be attributed to the differences in the index of refraction. Using DMA and DSC a more significant physical ageing was found for extruded films compared to extruded hollow profiles. As to the specific heat capacity values comparable results were obtained by the sapphire method and the alternating DSC method. Evaluating different methods for the determination of the thermal conductivity of the investigated polymers it was found that merely the isothermal-alternating DSC method allows the determination of reproducible thermal conductivity values which are in good agreement with values obtained by transient plane source reference measurements.
|Translated title of the contribution
|Characterization of Polymeric Solar Absorber Materials
|7 Apr 2006
|Published - 2006
Bibliographical noteembargoed until null
- solar absorber ATR UV/VIS/NIR DMA DSC specific heat capacity thermal conductivity