Starch/Poly(butylene adipate-co-terephthalate) Blown Films Containing Quaternary Ammonium Salts and...

In this study, quaternary ammonium salts (QAS) with different alkyl chain lengths (C12 and C18) were incorporated into starch/poly(butylene adipate-co-terephthalate) (PBAT) matrices with ethylenediaminetetraacetic acid (EDTA) to prepare blown films. The film with the combination of QAS and EDTA (D18D12E) achieved antibacterial rates of ≥99% against both Staphylococcus aureus and Escherichia coli, while maintaining cytocompatibility with HepG2 cells (viability ≥ 70%) and preliminary tobacco-growth compatibility. Compared with the control, the D18D12E film showed lower tensile strength (7.60 MPa) and higher oxygen (22.42 × 10^-13 cm³·cm·cm^-2·s^-1·Pa^-1) and carbon dioxide permeability coefficients (22.10 × 10^-13 cm³·cm·cm^-2·s^-1·Pa^-1). Its elongation at break (805.80%) and water vapor permeability (4.03 × 10^-11 g·m·m^-2·s^-1·Pa^-1) remained statistically comparable to those of the control. Furthermore, the D18D12E films delayed the visible deterioration of Chinese steamed bread and strawberries during 4 and 8 days of storage, respectively. These findings show that EDTA-assisted reduction in QAS loading can maintain antibacterial activity, but the associated mechanical and gas-barrier trade-offs require further formulation optimization.