Larry- I'm not certain if this is true of the boards you have in mind but the PVC sheet products I'm familiar with are not solid.
They have a surface skins on both sides and a rigid foamed core. They are very lightweight and stiff, can be cut with a saw or router and can be heat bent. One thing I wouldn't do is plane them. You would quickly go through the skin and into the core.
Maybe someone else can chime in regarding a solid sheet product. (or are you thinking of PVC "lumber"?)
I don't have direct experience with that. Won't speculate.
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.
I had some corner boards replaced with PVC and there was no trouble cutting them on a miter saw. I have cut many a PVC pipe with a hand saw with no problem. You probably would not damage your knives, but if the above comment from small boat holds true for boards, you may not have a usable board when you are done.
Looks like Bob has more info then I do. Sounds like you could plane or joint the boards when your knives are getting dull and need sharpening. Just like you do with teak.
I cut PVC on CNC machine all the time, the full 4x8 sheets from Home Depot and trim pieces sold at HD and Lowes. The shavings can melt back so you just have to learn the right feed and speed rate for good results. I've cut PVC on saws with no issues.