LAUSR

Paper is one of the most widely used materials, due to its application in books, packaging, and office supplies. However, conventional paper has many disadvantages, such as low tensile strength, poor resistance to water and oil contamination, lack of antigraffiti capability, and easily deformed by moisture. Therefore, we proposed a double-layer protective coating that consists of a polyurethane (PU) bottom layer, to enhance tensile strength, and a top polydimethylsiloxane (PDMS) composite layer to enable antigraffiti and contamination-resistant capabilities. In the study, a double-layer coating was applied to conventional paper, using a simple two-step spraying method. The results showed that the prepared coating structure exhibited outstanding self-cleaning characteristics with respect to both water and oil contamination and adequately demonstrated antigraffiti capability. Moreover, the coating maintained superhydrophobic and oil-stain resistance after four months of outdoor storage. Finally, the tensile strength of the coated paper was 6.3 times as high as that of the original paper, making this coating structure a promising solution to the problems that limit paper from being more widely utilized in commercial and consumer application.