But sometimes engineers deliberately add something that is supposed to react—and eventually wear out.
That's the clever idea behind rubber antidegradants such as 77PD.
Rubber may look tough, but oxygen and even tiny amounts of ozone in the atmosphere can slowly attack its molecular structure. Over time, a flexible material can harden, weaken, or develop cracks.
Instead of asking the rubber to survive every attack by itself, chemists give it something expendable.
77PD belongs to a family of molecules designed to react preferentially with damaging chemical species. While the rubber performs its mechanical job, these small protective molecules quietly consume themselves fighting chemical aging.
Global Chemical Database