Migration of copper from nanocopper/polypropylene composite films and its functional property

Abstract

Nanocopper with different concentrations was introduced to homopolymer polypropylene (PP-H) matrix to prepare nanocopper/PP-H composite film. Film appearance, mechanical and thermal properties were investigated. Migration test to 3% acetic acid (w/v) food simulant, film antibacterial ability and human hepatotoxicity were conducted to further evaluate film safeness. FTIR results suggest that nanocopper particles were physically dispersed in PP-H matrix and the addition of nanocopper could significantly improve thermal and mechanical properties of composite films, ensuring its potential utilization for food packaging. Also, the composite film showed great antibacterial ability including Escherichia coli, Staphylococcus aureus, Shigella castellani and Bacillus subtilis. At 70 ℃, when the initial concentration of added nanocopper reached 1% (w/w) or higher, the concentration of copper migrated from film to acetic food simulant would reach to 4.5 μg/g and would start damaging L-02 cells. This study provides important information for the potential utilization of nanocopper in food packaging films.