Wet Mechanically Stable, Biodegradable, and Weed-Controlled Corn Stover Mulch Films Based on Structural Rearrangement and Multiscale Interface Engineering

The widespread use of plastic mulch has caused serious environmental problems and poses a potential threat to human health. However, biomass-based films as the most commonly used alternative still exhibit unsatisfactory characteristics, including low wet mechanical stability, high processing costs, and harsh biodegradable conditions. Here, a high moisture retention capability (38 °C, 90 ± 2% RH) corn stover mulch film (CCP-PMF) with outstanding mechanical stability in both wet and dry environments is prepared by intrinsic lignin structural rearrangement and multimolecular-scale interfacial regulation synergy strategy. The elaborated composite films exhibited superior tensile index (68.9 N m g^–1), effective moisture retention (259.8 cc m^–2/24 h), and excellent biodegradability (28 days) compared to conventional mulches. Notably, the improved moisture resistance of CCP-PMF films allows for the integration of herbicides, resulting in CCP-PMF-based weed control films (AE-CCP-PMF) that provide a multifunctional solution for corn stover-based mulch films, broadening their potential for agricultural applications with lower environmental impacts (e.g., weed control film). This work demonstrates the potential of corn stover-based films as a sustainable alternative in agricultural practices, in line with the growing demand for environmentally friendly agricultural solutions (e.g., moisturized and biodegradable).