Development of antimicrobial and hydrophobic hot‐melt BioCoatings for cellulosic and biobased plastic substrates

This study addresses the growing need for sustainable, functional protection packaging by developing bio-based hot-melt coatings (HMCs) enriched with active biomolecules such as chitin, chitosan, and cutin. Current coatings are petroleum-based and not multi-functional and therefore, there is a necessity to discover more eco-friendly, high-performance alternatives. For this aim, a novel liquid-assisted extrusion process for efficient loading of bioactive compounds into a low-melting poly(butylene sebacate) (PBSe) matrix was explored. Optimized dispersing aids were used to form stable emulsions for homogeneous distribution of the biomolecules and prevention of agglomeration. Thermal and rheological measurements were carried out, and the resultant coatings were applied on both plastic and cellulosic substrates. The most significant findings include an extremely high rise in water repellency (hydrophobic behavior), mechanical behavior, and antimicrobial activity over bare substrates. Such improvement signifies the multifunctional ability of the coatings. The process adopted is easily scalable for industrial applications and represents a sustainable alternative to conventional coatings. Future studies will focus on the optimization of active loadings for specific end-use applications and evaluation of long-term environmental performance. Highlights: Developing bio-based hot-melt coatings with chitin, chitosan, and cutin. Using liquid-assisted extrusion for uniform biomolecule dispersion. Enhancing water repellence and antimicrobial properties. Improving mechanical strength on cellulosic and plastic substrates. Enabling scalable and sustainable industrial applications.