Improved physical and mechanical properties of food packaging films containing calcium hydroxide as a CO2 adsorbent by stearic acid addition

Abstract Stearic acid, SA (0, 1, 2, 3, 4 and 5%) was used to functionalize the surface of CO2-adsorbent powders to improve the physical and mechanical properties of active packaging LLDPE films. SA functionalization of calcium hydroxide/zeolite adsorbents was confirmed by the generation of a COO− symmetric stretching peak at 1404 cm-1 in Fourier transform infrared spectroscopy spectra. SA acted as a surfactant to reduce the agglomeration of the adsorbents in the film. Fewer aggregates resulted in improved tensile strength, reduced water vapor transmission rate, and increased light transmittance, which in turn improved the physical and mechanical properties of the films. When these films were used as packaging for kimchi, they did not affect the ripening of the kimchi, and showed excellent CO2 adsorption performance. When more than 2% SA was added to the adsorbent, the mechanical and physical properties of the film improved, and the carbon dioxide adsorption performance was good.