I've tried some carbon fiber PC before, it's hard as a rock, I tried breaking the infill with a pair of pliers and I could not get it to budge.
Hit it with a hammer and it didn't even phase it, finally dented it when I really hit it but I was very impressed.
I've made a variety of fan wheels over the last year or so, I have a hard time making the fins as strong as I would like, they tend to be weak right at the joint despite what kind of seam I do, if you are doing an impeller with a short stickout from the hub, I could see it working but your effeciency would be low.
I'm sure it could be possible, but I would be going for something with a little bit of flex in it, like Ninjatek Armadillo, I just made a fan wheel with it today, about 5 or 6 inches in dia on my Ender 6 and it came out great, enough flex to prevent it from snapping but not so flexible that it distorts.
But I've only tried very little PC with carbon fiber, but that was my experience.