Fabrication of hydrophobic cellulosic paper via physical vapor deposition of alkenyl succinic anhydride.

While plant fibers are abundant and biodegradable natural polymers, their high hydrophilicity often limits their applicability. To broaden the applicability of plant fiber materials across diverse fields, the present study employed cellulosic paper as a substrate and alkenyl succinic anhydride (ASA) as a low surface free energy material to fabricate a series of hydrophobic cellulosic papers (ASAP, ASA-P@Si, ASA-P@Ca, and ASA-P@Ti) through surface coating and physical vapor deposition of ASA. The results demonstrated that, in comparison to uncoated cellulosic paper, the coated variants exhibited significantly improved hydrophobicity. Notably, ASA-P@Si demonstrated superior hydrophobic performance with a contact angle of 140.90° and a sizing degree of 7.2 s, thereby meeting the requirements for specific fine paper grades. In contrast to the traditional ASA internal sizing process, the method in this study necessitates only approximately one-tenth of the conventional ASA internal sizing agent to achieve or even exceed the hydrophobic properties of paper attainable with ASA inter sizing process. Furthermore, the mechanism through which hydrophobic properties are conferred to paper can be elucidated by its surface roughness and low surface free energy, distinguishing it from the traditional ASA internal sizing approach.