Effects of poly(butylene adipate-co-terephthalate) coating on the water resistant, mechanical, and antibacterial properties of Kraft paper

A Kraft paper was coated with PBAT [poly(butylene adipate-co-terephthalate)] with Grapefruit seed extract (GSE) and zinc oxide nanoparticles (ZnONP) using different types of coating bars (No. 20, 30, 40, 50, and 60). The microstructure of the surface of the coated paper showed that the PBAT filled the pores of the porous fibers of the paper to make its surface smooth. The basis weight and thickness of the paper increased after coating. The properties of the coated paper, such as water resistance, water vapor barrier, surface hydrophobicity, and mechanical properties, increased significantly compared with the base paper. The tensile strength of coated paper increased by 40-80 % depending on the coating thickness. The paper coated with PBAT/GSE exhibited potent antibacterial activity against the Gram-positive bacteria (Listeria monocytogenes), while the paper coated with PBAT/ZnONP showed strong antibacterial activity against both Gram-positive (L. monocytogenes) and Gramnegative (Escherichia colt) bacteria.