Evaluation of Accelerated Aging Test Methods for Polymeric Materials in Solar Thermal Applications
Abstract
The long-term thermal stability (LTTS) of polymers is a major criterion for their applicability in solar thermal systems. For example, heat storage applications require a maximum service temperature of about 95°C. To ensure for a proper service, adequate test and evaluation procedures are needed to guard against excessive aging and premature failure. High temperature aging on a specimen level in application relevant environmental conditions is a common approach to evaluate the LTTS of polymeric materials. As shown in previous studies (Kahlen et al., 2010), aging testing on specimen level correlates well with aging results derived from more expensive tests on a component level. However, aging tests on common specimens with application relevant material thickness are usually time-consuming and limited in acceleration by simple enhancement of the testing temperature. Hence, advanced testing concepts are needed for efficient material screening for new applications in solar thermal systems. In the multi-partner cooperative research project SolPol-1 funded by the Austrian Climate and Energy Fund (KLI:EN) various concepts for accelerated aging testing of polymeric materials in solar thermal applications are currently under development and evaluation.