No, none of our products are considered UV stable, however, some are more resistant to UV damage than others. All of our polyurethane rubbers and plastics will yellow over time. Poly-Optic® 14-Series will yellow more slowly because they are Aliphatic urethanes. The one exception in the 14-Series is the 14-70 clear rubber.
In our rubber product lines, the Poly 75-65, Poly 75-79, and Poly 75-80 will hold up better outside, say for making stamping mats for concrete.
You can add a UV additive to delay the onset of damage from UV, but it will not prevent it. The only way to prevent UV damage is to cover or paint the part.