Nano-reinforced bioplastics for innovative packaging applications: Functional properties, antimicrobial mechanisms, and sustainability performance

Plastic packaging has witnessed significant growth over the past decades, with its wide industrial application ranging from food, biomedical, and to automotive sector, among others. It is estimated that a total of 8.3 billion metric tonnes of plastics have been produced since commercialization in the 1950s. Its strong market viability is attributed to its cost-effectiveness, lightweight, excellent material properties and durability. However, its non-biodegradable nature has contributed to substantial environmental pollution, health risks and climate change. To address this challenge, bioplastics have emerged as a promising solution, offering renewable and biodegradable end-of-life disposal options. According to industry reports, global bioplastics market is emerging and growing at a net annual rate of 12.6% from 2021 and is predicted to reach an estimated value of $26.3 billion by 2024. Despite this potential, the commercialization of pristine bioplastics has been constrained by factors such as high production costs and weak mechanical and barrier properties when compared to conventional petroleum-based plastics. This review critically examines nano-reinforced bioplastics as an innovative packaging solution to address the limitations of traditional bioplastics, including, inadequate mechanical strength, low barrier properties, and high moisture sensitivity. The study also discusses nanotechnology as a major breakthrough to revolutionizing the bioplastic packaging industries. Specifically, the review explores the various nanomaterials employed in enhancing the functionality and sustainability of biopolymer packaging, providing a comprehensive understanding of their properties, reinforcement mechanisms, and applications. The study focuses on nanomaterials ranging from nanoclays and carbon-based nanomaterials to metallic nanoparticles. In addition, it examines the functional properties of nano-enhanced bioplastics and provides an overview of the antimicrobial mechanisms of some essential nanomaterials. Finally, the review highlights the applications, challenges, and current trends in nano-based bioplastic packaging, and establishes a techno-economic sustainability roadmap for transition towards commercial scalability.