Effect of temperature and plasticizer content of polypropylene and polylactic acid on migration kinetics into isooctane and 95 v/v% ethanol as alternative fatty food simulants

Plasticizers are commonly used plastic additives. Deep understanding of their effect on the migration of other substances is essential, especially for food contact materials. The migration kinetics of four stabilizer-type additives from polypropylene (PP) and polylactic acid (PLA) with different tributyl acetyl citrate plasticizer content were investigated. The results confirm that the presence of plasticizer in the plastics enhances swelling, and thus the migration of additives. The plasticizer content is in strong correlation with migration rate for all additives, except for PLA-Irgafos 168 samples. Migration kinetic experiments conducted at different contact temperatures showed that the role of temperature apparently exceeds that of plasticization. Nevertheless, hierarchical cluster analysis revealed similarity in the migration mechanisms of stabilizers from plastics with low plasticizer content at high temperature, to that at low temperature from plastics with high plasticizer content.