Evaluation of thermal degradation in isotactic polypropylene films used in power capacitors

• Published in: Journal of thermal analysis and calorimetry 2017-11, Vol.130 (2), p.997-1002
• Main Authors: Teixeira, Mateus, Del Hoyo, Ignácio, Wandrowelsti, Fernando, Swinka-Filho, Vitoldo, Munaro, Marilda
• Format: Article
• Language: English
• Subjects: Ambient temperature; Analytical Chemistry; Capacitors; Chemistry; Chemistry and Materials Science; Dielectric breakdown; Dielectric materials; Dielectric strength; Electric properties; Electric utilities; Electronic components industry; Heat measurement; Inorganic Chemistry; Intermetallic compounds; Isotacticity; Measurement Science and Instrumentation; Operating temperature; Physical Chemistry; Polymer Sciences; Polypropylene; Polypropylene films; Power consumption; Thermal analysis; Thermal degradation; Thermodynamic properties
• ISSN: 1388-6150; 1588-2926
• DOI: 10.1007/s10973-017-6400-7

Power capacitors are widely used by electric power utilities in electrical systems to improve power quality for their consumers. However, problems with physical installation, ambient temperature and electrical disturbances can raise the internal operating temperature above the ideal designed for the component, which can accelerate the degradation of the dielectric material. Since polypropylene film is the main part of the capacitor dielectric system, it is important to know about the effects of thermal aging on the physicochemical properties of the material. This work presents results of physical–chemical characterization tests of thermal aged isotactic polypropylene (iPP) film used in power capacitors. Tensile strength tests, dynamic mechanical thermal analysis, differential scanning calorimetry, X-ray diffraction (WAXS) and dielectric strength were performed. The results showed that the thermal aging causes morphological changes and reduction in the dielectric breakdown voltage of the iPP film.