Hydrophobic Polyvinyl Alcohol and Microcrystalline Cellulose From Hemp Waste Composite Films by Using Alkyl Ketene Dimer Wax for Packaging Applications

ABSTRACT Polyvinyl alcohol (PVA) composite films are a promising biodegradable material for various applications, particularly in packaging. These films are typically prepared using an aqueous solution and casting method. Microcrystalline cellulose derived from hemp waste was incorporated as an additive to enhance its mechanical properties. The alkali treatment, bleaching treatment, and acid hydrolysis were used to synthesize the microcrystalline cellulose from hemp waste (CHW). The size of CHW was about 13 ± 1 μm and 64% crystallinity. PVA/CHW composites were prepared using the casting method, with the CHW contents being 1, 3, 5, and 7 phr. The mechanical properties were illustrated, with PVA/CHW 3 phr showing the highest tensile strength. Moreover, the PVA/CHW composites showed good compatibility, as observed by SEM images. Thus, alkyl ketene dimers (AKD) wax was coated by a rod‐coater to improve the hydrophobicity. The film coated with AKD showed a significant increase in the water contact angle. Nevertheless, AKD coating reduced the light transmittance of the film in both the UV and the visible ranges. Lastly, the PVA/CHW composites improved the resulting mechanical properties. The hydrophobicity of the film was developed by AKD to produce biodegradable materials that can be used as a food packaging film.