Short answer: PVC boards will dull planer and jointer knives much faster than regular wood.
The PVC boards I've seen were intended for architectural ornamentation and trim. They had a nice edge and flat surface but the interior was foamy stuff, probably a type of PVC. On edge on a jointer, there will be two slight grooves where the outer edges of the board ran.
There's also type 1 PVC, but that's expensive and not likely found in other than industrial plastics suppliers.
Sometimes the value or the immediate need of the work will exceed the replacement costs of the planer & jointer knives.