Due to its highly stable chemical bonds, PPS shows extremely good heat aging performance. The phenylene rings will form a carbon layer during the initial aging process. Later, it will protect the inner layer from oxidizing. It can easily be validated by the heat aging curve, pictured to the right, for G4010T. It is shown that only a limited reduction of tensile strength is observed at 150°C, while there is a bit more reduction at 230°C, yet reduction is still limited. Even after aging at 230°C for 6,000 hours, Xytron G4010T still shows > 60% tensile strength retention.