A FOURIER-TRANSFORM RAMAN-SPECTROSCOPY STUDY OF WATER SORPTION BY POLY(VINYL ALCOHOL)

The Fourier transform (FT) Raman spectrum of poly(vinyl alcohol) (PVA1 ) is reported. The spectra of PVA1 exposed to different aqueous enviro nments are also reported. The changes to the FT Raman spectrum of PVA1 in the presence of water provide evidence of several forms of water i n the polymer. For PVA1 exposed to an environment of 75% relative humi dity, it is postulated that water molecules disrupt the inter-chain hy drogen bonding which exists in the polymer and produce an augmented hy drogen bonding. For the case of exposure to a 100% relative humidity e nvironment, evidence is provided for the existence of liquid-like wate r clustered between the crystallites of PVA1. (C) 1997 Elsevier Scienc e B.V.