Oxygen barrier and antibacterial properties of polyamide 1010/amino acid fully renewable blown films

Fully biobased blown films with excellent oxygen barrier or antibacterial properties were innovatively prepared by incorporating small contents (<3 wt%) of heat‐resistant amino acid (i.e. glycine (GLY), l ‐glutamate (LGLU) or l ‐alanine (LALA)) in polyamide 1010 (PA1010). All oxygen transmission rate (OTR) or free‐volume‐cavity (FVC) characteristic values of PA1010/GLY, PA1010/LGLU and PA1010/LALA blown films decrease to a minimum as GLY, LGLU or LALA content approaches its respective compatibility limit value. The minimum OTR value acquired for PA1010/LGLU and PA1010/LALA blown films is remarkably low at 3.1 and 2.3 cm 3  m −2  day −1  atm −1 , respectively, while their Staphylococcus aureus (SA) antibacterial rates are ≥99%, which meet the requirements of high oxygen barrier (OTR ≤ 5 cm 3  m −2  day −1  atm −1 ) or antibacterial (SA antibacterial rate ≥ 99%) films. The transversal and longitudinal tensile strengths of suitably made PA1010/GLY, PA1010/LGLU and PA1010/LALA blown films are ~20%, ~30% and ~40%, respectively, higher than those of the PA1010 blown films. Dynamic mechanical and Fourier transform infrared analyses reveal that GLY, LGLU and LALA are compatible with PA1010, as the amino acid contents remain below the compatibility limit value of 1.0, 2.75 and 1.25 wt%, respectively. These substantially diminished OTR and improved tensile strength values of suitably made PA1010/GLY, PA1010/LGLU and PA1010/LALA blown films are mostly attributed to the diminished FVC characteristic values resulting from the strengthened molecular interactions between amino acid and PA1010, as GLY, LGLU or LALA contents approach the corresponding compatibility limit values. © 2026 Society of Chemical Industry.