Preparation and characterization of poly(butylene adipate‐co‐terephthalate) composites reinforced with acetylated cellulose nanocrystals and nanofibers for enhanced properties

Abstract

AbstractNanocellulose‐reinforced composites hold great promise for outperforming the original polymer matrix by offering exceptional properties, including outstanding barrier characteristics achieved through the establishment of convoluted pathways for the diffusion of water vapor and gases, as well as superior mechanical and thermal properties. Nevertheless, a significant challenge when employing nanocelluloses as reinforcements in polymers arises from their limited compatibility with the polymer matrix, primarily attributed to the abundance of surface hydroxyl groups.To address this limitation, this study focuses on the acetylation modification of cellulose nanocrystals (CNC) and nanofibers (CNF) to enhance their compatibility with the polymer matrix. Poly(butylene adipate‐co‐terephthalate) (PBAT) nanocomposites were developed by incorporating 1 wt% of both untreated and acetylated cellulose. The process involved the molten state mixing of these components using a twin‐screw mini extruder, conducted at 160°C for 7 min. The efficacy of the acetylation process was verified through Fourier transform infrared spectroscopy (FTIR). Scanning electron microscopy (SEM) analysis confirmed the favorable interaction and dispersion of nanocelluloses within the polymer matrix. Importantly, introducing these fillers did not compromise thermal stability but notably enhanced the hydrophobic characteristics of the samples, as confirmed by contact angle measurements. Dynamic mechanical analyses further demonstrated the compatibility and effective interaction between the polymer and fillers. This research uniquely provides a comparative analysis of the effects of acetylated CNC and CNF within a PBAT matrix, unveiling distinct interactions and performance enhancements. Each type of nanocellulose exhibits its own characteristic ways of bonding and dispersing, leading to varying performance improvements for the material. This comparison elucidates the nuanced roles that these nanocelluloses play in reinforcing composites, offering insights into optimizing their contribution to polymer matrices. By demonstrating the differential impact of CNC and CNF post‐acetylation, our study contributes significantly to the field of polymer science, guiding future applications of nanocellulose‐reinforced materials in advanced engineering and sustainability efforts.