Improving moisture barrier properties of paper sheets by cellulose stearoyl ester-based coatings

As commonly-used packaging material, paper has very poor moisture barrier properties, which are essential for maintaining physical and mechanical performance of paper as well as the shelf life of the packed goods. Herein, solutions of the synthesized cellulose stearoyl ester (CSE) compound were coated onto the calendered paper sheets by bar coater with the coating grammage ranging from 0.5-23.6 g m^-2. When the coating grammage was 5.2 g m^-2, the paper surface was totally covered by the CSE film with very low surface roughness (2.327 nm). The resulting CSE-coated papers from this coating grammage showed decreased tensile index and increased elongation at break, indicating the flexibility of the coated papers. Furthermore, the coated paper sheets were hydrophobic and displayed competitive water vapor barrier properties with the barrier ratio up to 90 %. Thereby, the designed CSE-coated paper sheets are promising for moisture barrier packaging application.