Preparation of simple biodegradable, nontoxic, and antimicrobial PHB/PU/CuO bionanocomposites for safely use as bioplastic material packaging

Abstract

Plastic waste in Egypt is causing a problem. An innovative solution to reduce this pollution is inevitable. Microalgae were considered a new resource for developing biobased bioplastics. This study aims to prepare a simple biodegradable film able to use in packaging and from polyurethane (PU) nanocomposite with Poly 3-hydroxybutyrate (PHB) in the presence of various concentrations of CuO-NPs. The Poly 3-hydroxybutyrate compounds were extracted from the dominant microalgal species in High rate algal pond Microcystis sp. Algal extracts have antimicrobial activities against Escherichia coli, Salmonella Typhimurium, Pseudomonas aeruginosa, Staphylococcus aureus, Listeria monocytogenes, Enterococcus faecalis, and Candida albicans. Films prepared from PHB, and PU showed no cytotoxic impact on human tumor cell lines in terms of cell viability. The mechanical properties of the films were studied, and it was found that the final contact angle values were improved from 77° to 87° as CuO-NPs loading raised from 2 to 4%, respectively. XRD displays no difference in the intensity of CuO-NPs peaks by increasing CuO-NPs loading in the PHB/PU matrix. FTIR spectra of all blends were recorded in the range of 400 to 4000 cm−1. Tensile properties were improved with the addition of 40 wt.% PHB.