Preparation and characterization of films of starch/poly(vinyl alcohol)/polyurethane blend

GONZÁLEZ FORTE, L.; PARDINI, O.; AMALVY, J. I.; MARTINO, M. N.

Porto de Galinhas

Simposio; Simposio Latino Americano de Polímeros; 2014

We have prepared a polyurethane (PU) dispersion and then used it to modify a blend of starch and poly(vinyl alcohol) (PVA) with high starch content (70 wt. %). Films were prepared by casting the aqueous dispersions of gelatinized starch, PVA and PU. The effect of PVA/PU ratio content on the morphology, miscibility and physical properties of the resulting materials was investigated by infrared spectroscopy, modulated differential scanning calorimetry, thermogravimetric analysis, scanning electron microscopy and measurements of mechanical properties and water vapor permeability. The results show that starch/PVA can be blended with polyurethane at molecular level forming blends without phase separation. Hydrogen bond interaction between starch/PVA and PU plays a key role in the improvement of the material performance. The incorporation of PU into the starch/PVA matrix leads to an improvement of mechanical and barrier properties. Natamycin is also incorporated in the matrix as antifungal agent and preliminary results are presented.