Five different PVA/PAA blend films were prepared via the solution
blending method with heat treatment, and their physical characteristics
(including barrier, thermal, mechanical and optical properties)
were investigated as a function of PAA ratio. The physical
properties of the PVA/PAA blend films were strongly dependent
upon the chemical structure and morphology of the films. The
blend films were formed by esterification reactions between the
hydroxyl groups in PVA and the carboxylic acid groups in PAA,
resulting in a crosslinked network and changed chemical structure.
With increasing PAA ratio, the crosslinking density was increased,
resulting in more compact packing of the molecule