From thermal desorption studies, we find evidence that absorbed water in the bulk of poly(methylvinylidene cyanide) is more weakly bound than is the case for copolymer films of poly(vinylidenefluoride-trifluoroethylene). Ultraviolet laser enhanced thermal desorption of absorbed water exhibits little light polarization dependence for poly( methylvinylidene cyanide) in contrast to absorbed water in copolymer films of poly(vinylidenefluoride-trifluoroethylene). The implications of these differences are discussed.