There are how many kinds of PVC impact modifier? Which is the best?

There are how many kinds of PVC impact modifier? Which is the best?

Three types: CPE, Acrylate and ABS based.
Better Impact at low dosing : ABS is good, but poor UV stability
Needs better UV Stability : Acrylate best.
CPE more dosing is required to have Impact strength similar to what you get with Acrylate based.