If you buy a good grade boat, you won't have to worry about it. Check the denier rating and the oz of material on the seams. Those will normally tell the tale. Not sure of a coating, usually they put skid pads on to help chaffing of frame. But rarely is needed. My 16' cataraft is one of the first production catarafts on the market. Now it's (I'm amazed after I did the math and figured out it's age wrong) roughly 15 years old!!!! It's still going strong, and the tubes are in excellent shape for all the use they've had (have been on some of the US's toughest whitewater runs). Never had any extra treatment nor extra skid pads.
Buy a quality set of tubes/boat you'll have no worry.
"Good angling ethic is not a monopoly practiced just by fly fisherman" - Bill McMillan