Towards Sustainable Packaging Using Microbial Cellulose and Sugarcane (Saccharum officinarum L.) Bagasse

Abstract

The high consumption of packaging has led to a massive production of waste, especially in the form of nonbiodegradable polymers that are difficult to recycle. Microbial cellulose is considered a biodegradable, low-cost, useful, ecologically correct polymer that may be joined with other biomaterials to obtain novel characteristics and can, therefore, be used as a raw material to produce packaging. Bagasse, a waste rich in plant cellulose, can be reprocessed and used to produce and reinforce other materials. Based on these concepts, the aim of the current research was to design sustainable packaging material composed of bacterial cellulose (BC) and sugarcane bagasse (SCB), employing an innovative shredding and reconstitution method able to avoid biomass waste. This method enabled creating a uniform structure with a 0.10-cm constant thickness, classified as having high grammage. The developed materials, particularly the 0.7 BC/0.3 SCB [70% (w/w) BC plus 30% (w/w) SCB] composite, had considerable tensile strength (up to 46.22 MPa), which was nearly thrice that of SCB alone (17.43 MPa). Additionally, the sorption index of the 0.7 BC/0.3 SCB composite (235.85 ± 31.29 s) was approximately 300-times higher than that of SCB (0.78 ± 0.09 s). The packaging material was also submitted to other analytical tests to determine its physical and chemical characteristics, which indicated that it has excellent flexibility and can be folded 100 times without tearing. Its surface was explored via scanning electron microscopy, which revealed the presence of fibers measuring 83.18 nm in diameter (BC). Greater adherence after the reconstitution process and even a uniform distribution of SCB fibers in the BC matrix were observed, resulting in greater tear resistance than SCB in its pure form. The results demonstrated that the composite formed by BC and SCB is promising as a raw material for sustainable packaging, due to its resistance and uniformity.