Preparation of waste poly(lactic acid) based seagrass and leonardite added biocomposite mulch films from solution casting method and investigation of their properties

The relationship between the use of chemical fertilizers, pesticides, and petroleum-derived mulch films for ensuring an adequate food supply, greenhouse gas emissions, product safety, and plastic pollution is being discussed. Recently, the increasing use of petroleum-derived mulch films for soil protection and productivity has led to soil pollution. Consequently, there has been a growing interest in researching and utilizing biodegradable polymers and biocomposites as alternatives to petroleum-based polymers. Finding solutions to waste issues through recycling and upcycling emerges as a significant value in the context of circular economy and sustainable development. In this study, waste poly(lactic acid) (PLA) filament from 3B printing machines was evaluated. Films with different compositions of PLA, seagrass (Posidonia oceanica), leonardite, and Polyethylene Glycol (PEG) 6000 were prepared using a solution casting method. The structure of these films was determined using a Fourier Transform Infrared Spectrometer (FT-IR), the morphological properties of the film surfaces were examined using a Scanning Electron Microscope (SEM), and the gloss qualities were evaluated using a glossmeter. The thermal properties were investigated through Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA). The mechanical properties were determined through tensile testing. Furthermore, the biodegradability properties of the films were examined through soil burial testing. The addition of fillers enhanced the biodegradability of PLA.