Aging behavior of polymeric solar absorber materials – Part 1: Engineering plastics

• Published in: Solar energy Vol. 84; no. 9; pp. 1567 - 1576
• Main Authors: Kahlen, S., Wallner, G.M., Lang, R.W.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.09.2010; Elsevier; Pergamon Press Inc
• Subjects: AIR; AMORPHOUS MATERIALS; Applied sciences; Chromatography; Commodities; COMPARATIVE EVALUATIONS; DECOMPOSITION; Differential scanning calorimetry; Electrical engineering. Electrical power engineering; Energy; Engineering polymers; ETHERS; Exact sciences and technology; High temperature; Materials; MATERIALS SCIENCE; Natural energy; Photovoltaic cells; Physical and chemical aging; Polyamide resins; POLYAMIDES; POLYCARBONATES; Polyethylenes; Polymers; Polyphenylene ethers; Polypropylenes; POLYSTYRENE; Polystyrene resins; Series & special reports; SOLAR ABSORBERS; SOLAR COLLECTORS; SOLAR ENERGY; Solar thermal application; Solar thermal conversion; STRAINS; TEMPERATURE RANGE 0273-0400 K; TEMPERATURE RANGE 0400-1000 K; TENSILE PROPERTIES; Tensile strength; WATER; WEATHERING; Solar thermal application; Physical and chemical aging; Engineering polymers; Differential scanning calorimetry; Amorphous material; Nylon; Solar collector; Ageing; Phenylene polymer; Polymer films; Solar absorbers; Operating conditions; Mechanical test; Crystalline material; Styrene polymer; Plastics; Polycarbonate; Damaging
• ISSN: 0038-092X; 1471-1257
• DOI: 10.1016/j.solener.2010.03.021

In this series of two papers, various polymeric materials are investigated as to their potential applicability as absorber materials for solar thermal collectors. The focus of the investigation is to study the aging behavior of these materials under maximum operating conditions (80 °C in water up to 16,000 h) and stagnation conditions (140 °C in air up to 500 h) typical for northern climate. The materials supplied or produced as polymer films were first characterized in the unaged state and then for different states of aging by differential scanning calorimetry (DSC), by size exclusion chromatography (SEC) and by mechanical tensile tests. Physical aging phenomena were studied by DSC, SEC analysis provided information on chemical degradation of the materials. In addition, physical and chemical aging were both analyzed via the small and large strain mechanical behavior. While the present Part 1 of this paper series deals with the aging behavior of engineering plastics, including two amorphous polymers (a polyphenylene ether polystyrene blend (PPE + PS) and polycarbonate (PC)) and two semi-crystalline polymers (two types of polyamide 12 (PA12)), the aging behavior of so-called “commodity” plastics (PE and PP) is the subject of Part 2. Comparing the two aging conditions, the amorphous materials (PPE + PS and PC) turned out to be more prone to physical and chemical aging at 140 °C in air. In contrast, the semi-crystalline PA12 materials were more strongly affected by exposure to water at 80 °C, although to different degrees, depending on the modification.