Degradation of Polycarbonate Properties Under Thermal Aging

The aim of this paper is to characterize the thermal aging effect near the glass transition temperature of polycarbonate (PC) at different hold time. For this, the physicochemical characterization and mechanical behavior of PC after annealing at 120 °C for 72, 144 and 216 h were investigated. The microstructural analysis was conducted by scanning electron microscopy (SEM) and x-ray diffraction (XRD). Then, the aged samples were also analyzed using thermogravimetric analysis and mechanical tests. The microcracks were revealed by the SEM, and an increase in the volume of crystalline domains, for 72 and 144 h of the aging, was highlighted by XRD. Furthermore, a decrease in Young’s modulus and microhardness of PC was noted. It seems that the annealing of the PC at 120 °C, during the three durations, caused physical and chemical aging producing break in the bonds leading to a beginning of degradation which can cause a sudden failure of the material.