Antibacterial activity, thermal behavior, mechanical properties and biodegradability of silver zeolite/poly(butylene succinate) composite films
In recent work, the antibacterial packaging film from biodegradable polymer was prepared. Poly(butylene succinate) (PBS) composite films containing three different antibacterial agents; silver zeolite A (AgZA), silver zeolite Y (AgZY) and silver zeolite ZSM-5 (AgZSM-5), at the concentration of 0.5–4%wt were produced by solvent casting and melt extrusion techniques. The effects of processing methods and antibacterial agents on the antibacterial activity, thermal and mechanical properties, including biodegradability of PBS composite films have been investigated. The antibacterial activity results revealed that AgZSM-5/PBS composite films had higher efficiency in antibacterial activity than the films with AgZA and AgZY. AgZSM-5/PBS composite films presented 99.9% of bacterial inhibition even at 0.5%wt of AgZSM-5. Thermal properties of PBS films were examined by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The decomposition products of PBS composite films were analysed by pyrolysis/gas chromatography–mass spectroscopy (Py/GC–MS). The thermal degradation kinetic of PBS composite films was also studied. The activation energy of PBS composite films degradation was calculated by Kissinger and Flynn-Wall-Ozawa models, which were decreased as AgZA/PBS > AgZY/PBS > AgZSM-5/PBS. For the Kissinger method, the activation energies of PBS, AgZA/PBS, AgZY/PBS and AgZSM-5/PBS composite films were found to be 303.5, 251.8, 235.3 and 228.8 kJ/mol, respectively. Soil burial test was used to investigate the biodegradable properties of PBS composite films. PBS films were initially biodegraded after a month of soil burial test. PBS films with silver zeolite loading still showed the biodegradable activity after 3 months of soil burial test, although with lower biodegradation rate compared with neat PBS.