Preparation and characterization of polystyrene/starch blends for packaging applications

MARTIN BERRUEZO; LEANDRO NICOLAS LUDUEÑA; EXEQUIEL S. RODRIGUEZ; VERA ALEJANDRA ALVAREZ

JOURNAL OF PLASTIC FILM & SHEETING

SAGE PUBLICATIONS LTD

Lugar: London; Año: 2014 vol. 30 p. 141 - 161

8756-0879

Polystyrene (PS) / thermoplastic starch (TPS) blends from 90/10 to 50/50 (w/w) were prepared by melt blending. Blends were characterized by Scanning Electron Microscopy (SEM, morphology); thermogravimetric analysis (TGA, thermal stability and weight content of each component); Fourier Transform Infrared Spectroscopy (FTIR, identification of functional groups); Differential Scanning Calorimetry (DSC, thermal properties); tensile tests (strength, modulus, elongation at break and tenacity) and biodegradation in soil (biodegradability). The biodegradation process was also followed by TGA calculating the loss of each component after removing the samples from soil at different time intervals. SEM results showed a good starch dispersion in the blend. The FTIR analysis suggested that only physical interaction took place between the PS and the TPS. The tensile tests revealed a considerable decrease in the mechanical properties of the PS-TPS blends as a function of the TPS content. The 50/50 blend showed decreases of 48 % in the Young´s modulus, 62 % in the tensile strength, and increases of 62 % in the elongation at break, in comparison to neat PS. The biodegradability tests showed that the greater the TPS concentration in the blend, the faster the mass loss, which was also confirmed by the TGA and FTIR analysis.