Hydrophilic films based on blends of poly(acrylic acid) and poly(2-hydroxyethyl vinyl ether): Thermal, mechanical, and morphological characterization

Hydrophilic films based on blends of poly-(acrylic acid) and poly(2-hydroxyethyl vinyl ether) were prepared by casting. The characterization of the films was performed by differential scanning calorimetry (DSC), dynamic mechanical thermal analysis (DMTA), and scanning electron microscopy (SEM). It was shown that an increase of poly(2-hydroxyethyl vinyl ether) content in the blends considerable decreases the glass transition temperature of the samples. The film containing 10 and 20 mol% of poly(2-hydroxyethyl vinyl ether) show behavior of polymers in the glassy state, but a further increase of nonionic polymer content in the blend (30-50 mol%) provides the mechanical properties typical of a rubbery state. The content of water traces in the films has a significant effect on the mechanical properties of the materials.