One the biggest technological advancements in plastics over the last 30 or so years have been the improvement in UV stability. I can remember how fast vinyl dashboards in cars used to split and crack from sunlight exposure. Today, you rarely see that until the car has been in the junk yard for a few years. Even white vinyl siding and fencing seem to hold their color reasonably well for a decade or more. This is thanks to additives manufacturers developing really sophisticated stabilizers and anti-oxidants that can be compounded into various plastic materials.
In this post, I wanted to de-mystify what causes UV damage to plastics and how UV stability is tested.