engleski

Investigation of acetyltributyl citrate migration from poly(3-hydroxybutyrate) into food simulants

Plastics have developed into the most important class of packaging materials for food and consequently more information on the interactions between plastic packaging materials and food is required. Poly(3-hydroxybutyrate) (PHB) is fully biodegradable aliphatic polyester with some physical and mechanical properties comparable to those of isotactic polypropylene. Therefore, PHB has been considered as an alternative to petroleum-based plastics for food packaging. The main disadvantages of PHB are its pronounced stiffness and brittleness which can be improved by addition of plasticizers. Plasticizers are low molecular weight synthetic organic molecules, added to the polymer in order to modify its mechanical properties. Such additives normally possess a high mobility due to relatively low molecular weight and easily diffuse to the surrounding media (food, solvent etc.), particularly in those with a high fat content. Migration of plasticizers from plastic materials in contact with food is of great importance considering potential impact on human health.In this work, the global migration from PHB plasticized with acetyltributyl citrate (ATBC) in food simulants during ten days at room temperature was investigated by means of gravimetric method. Distilled water, 3 % acetic acid, 10 % ethanol and sunflower oil were used as food simulants. It was found that the amount of plasticizer migrated per unit area (Mt) increases with time as well as with increasing ratio of ATBC. The greatest migration was observed in sunflower oil as food simulant. The thermal characteristics of the samples were determined before and after ten days exposure in food simulants by means of differential scanning calorimetry. It was found that ATBC is good plasticizer for PHB. The slight increase of Tg and Tm were observed in the samples after migration that can be attributed to the migration of plasticizer to food simulants.

Poly(3-hydroxybutyrate) (PHB); Migration of plasticizers; Differential scanning calorimetry

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