The recent progress in the field of organic conducting polymers were best regarded as an alternative to conventional silicon based solar cells for low-cost energy source. However, these organic based materials are sensitive towards moisture and oxygen in the ambient, it needs hermitic protection (WVTR 10-6 g/m2/d and OTR of 10-5 g/cm2/d). The use of high barrier polymeric materials can greatly reduce the permeability of ingress gases to the active device layer and also suitable for large area applications. Poly(vinyl butyral), a tough and transparent polymer, an inter-layer film in the laminated safety-glass industry has also been in application for solar module encapsulant. The inclusion of ionic groups in the polymer matrix acts as a thermally reversible cross-linker and offers flexibility with enhanced resistance for gas permeation. In this work, poly(vinyl butyral) containing benzyl carboxylate moieties (8, 10, 15 and 21 mole percent) were copolymerized with poly(vinyl alcohol) followed by acetalization with n-butyraldehyde. These acidic copolymers were neutralized with sodium and zinc ions with 30 – 35% neutralization of acid groups. These ionomers were solvent casted in to a film thickness of 40 µm. Calcium degradation technique was used to access the moisture permeability behavior of these films under various levels of humidity and temperature. Al/P3HT/ITO Schottky structured devices were encapsulated by the I-PVB films and its change in current density percent (%CD) were evaluated. The level and type of ionic content to the thermal stability, glass-transition behavior, UV stability and dynamic mechanical properties in poly(vinyl butyral) ionomers were presented in the light existing mechanism of the cluster/multiplet formation in these films. Finally, the PVB ionomers were used as an interlayer in olefinic films were carried out to enhance moisture barrier flexible encapsulants for organic devices