Polymer films for solar energy applications—thermoanalytical and mechanical characterisation of ageing behaviour

This work describes the ageing and artificial weathering behaviour of commercial polymer films with thickness of approximately 50 μm for transparent insulation wall applications. The investigated polymers are transparent in the solar range and strongly absorbing in the infrared range. Sufficient absorption in the infrared range is reached by using polymers with carbon-oxygen single bonds. The paper focuses on the characterisation of the ageing behaviour by thermoanalytical and mechanical methods. Useful details on overall ageing phenomena are obtained by thermal analysis. Mechanical characterisation of both, unnotched and notched specimens provides additional information on the nature of ageing, specifically with regard to the occurrence of local ageing and the development of defects.