Mechanical, thermal and morphological characterization of polypropylene/biodegradable polyester blends with additives

The (bio)degradation of polyolefins can be accelerated by modifying the level of crystallinity or by incorporation of carbonyl groups by adding pro-oxidants to masterbatches or through exposure to ultraviolet irradiation. In this work, we sought to improve the degradation of PP by adding cobalt, calcium or magnesium stearate to Ecoflex®, PP or Ecoflex®/PP blends. The effect of the pro-oxidants on biodegradability was assessed by examining the mechanical properties and fluidity of the polymers. PP had higher values for tensile strength at break and Young's modulus than Ecoflex®, and the latter had little influence on the properties of PP in Ecoflex®/PP blends. However, the presence of pro-oxidants (except for calcium) reduced these properties. All of the pro-oxidants enhanced the fluidity of PP, a phenomenon that facilitated polymer degradation at high temperatures.