This work reports the synthesis and miscibility of PET/PLA and PET/chitosan blends as well
as their degradation in real soil environment (6 months) and in accelerated weathering
(1200 h). For this purpose, commercial polyethylene terephthalate (PET) and recycled
PET (R-PET) were used as polymer matrixes and extruded with different amounts of polylactic
acid (5, 10 and 15 wt-%) or chitosan (1, 2.5 and 5 wt-%) to form filaments. Different
characterization techniques such as X-ray diffraction (XRD), Fourier transform infrared
spectroscopy (FTIR), differential scanning calorimetry/thermogravimetric analysis (DSC/
TGA) and scanning electron microscopy (SEM) were used before and after degradation process.
The results indicate weak interactions between blend components suggesting secondary
bonds by hydrogen bridges or by electrostatic forces. The miscibility of chitosan in both
PET matrixes is lower in comparison with PLA; the saturation of PLA into polymer matrixes
was reached up to an amount of 10 wt-% whereas longer amounts of 5 wt-% of chitosan
become rigid and brittle. The best performance in the miscibility and degradation process
was found for PET/chitosan (95/5) which is comparable with commercial bottles of BioPET
under similar experimental conditions.