Effects of photodegradation and thermal ageing on the scratch behavior of uncoated thermoplastic olefin

This study examined the effects of exposure to thermal ageing and weathering conditions on the scratch resistance of an uncoated thermoplastic polyolefin system over a period of 1800h. A flatbed scanner and scanning electron microscopy were used to observe the surface characterization and morphology for the scratch-induced damage of the aged TPO systems. The number of oxygen containing polar functional groups, amount of talc, crystallinity and discoloration on the TPO surface increase with increasing ageing time. At the same time, the number of hydrocarbon groups decreases. These findings suggest that the hydrocarbon groups locally undergo oxidation on the TPO surface due to thermal ageing and weathering. The abovementioned changes lead to an increase in scratch resistance and performance. [Display omitted] •The effects of photodegradation and thermal ageing on scratch behaviors were studied.•Linearly increasing and decreasing load scratch tests were performed.•An increase in ageing time leads to an increase in scratch resistance.•The correlation between the scratch coefficient of friction and scratch behavior is discussed.