Dually Modified Starch‐Based Coating for Improving Barrier and Mechanical Performances of Paper Toward Food Packaging

ABSTRACT Paper is a promising packaging material, while raw paper always presents poor barrier and mechanical performances. Developing high‐performance coating is an effective strategy to expand its applications. In this paper, a biobased high‐performance coating was developed via dual modifications on starch. Specifically, starch was first modified using polyethylenimine (PEI), and then grafted using the hydrophobic methyltrimethoxysilane (MTMS). The finally obtained dually modified starch (PM‐St) enabled paper to display favorable barrier properties, including excellent water resistance (static contact angle of ~128°) and oil‐proof performance (oil‐proof grade > 7). Furthermore, the coated paper also exhibited obviously enhanced mechanical performances, including improved tensile index of 46.88% and improved burst index of 81.69% for coated paper. In conclusion, this biobased coating has the potential for application in paper coating toward food packaging and thus reduces the use of plastic materials.