Slow‐Release Films Prepared by Halloysite Nanotubes Loaded With Herbicide

ABSTRACT As the level of industrialization continues to rise, soil pollution, including “white pollution,” has become increasingly severe. Consequently, mulch films made from biodegradable plastics have garnered significant attention. However, weeds growing beneath the mulch films can damage them, rendering them unable to perform their intended functions. Therefore, when using biodegradable mulch films, it is essential to employ a herbicide with a controlled release rate. In this study, a reactive compatibilizer, polymethylene polyphenyl polyisocyanate (PAPI), was first added to a poly(butylene adipate‐co‐terephthalate) (PBAT)/polypropylene carbonate (PPC)/poly(lactic acid) (PLA) blend to enhance its compatibility. Compared to pure PBAT films, the tensile strength, Young's modulus, and water vapor barrier properties of the PBAT/PPC/PLA/PAPI (60/30/10/0.7 weight ratio) composite films improved by 59%, 122%, and 62%, respectively. Subsequently, SHNT was prepared by etching halloysite nanotubes (HNT) with sulfuric acid, and the herbicide glufosinate‐ammonium (Glu) was loaded into the SHNT tubes using a vacuum method to form Glu@SHNT. The Glu@SHNT was then melt‐blended with PBAT/PPC/PLA/PAPI and flow‐cast into films. Compared to directly incorporating Glu into the films, Glu@SHNT exhibited excellent slow‐release properties, preventing the premature release of the herbicide before weed growth. Furthermore, the addition of Glu@SHNT enhanced the crystallization rate, gas barrier properties, and mechanical properties of the films. This study opens up a new avenue for research on herbicide‐loaded biodegradable mulch films, contributing to long‐term weed control and reducing the use of polyolefin‐based mulch films.