Mechanical Behavior and Thermal Stability of EVA Encapsulant Material Used in Photovoltaic Modules

The mechanical behavior and the thermal stability of an encapsulant based on ethylene-vinyl acetate (EVA) were studied. The EVA properties were verified at temperatures ranging from −70 °C to 500 °C. Thermogravimetry, differential scanning calorimetry and dynamic mechanical analysis were used in this study. It has been shown that the encapsulant has a good weight stability; however, the encapsulant passes through both a glass transition and a melting phase in the range of operating temperatures. The kinetic parameters of crosslinking were also analyzed. It is possible to achieve 65% crosslinking at a temperature of 150 °C and a time of 5 minutes. The activation energy of crosslinking is 95.6 kJ/mol.