Poly(butylene adipate-co- terephthalate) - PBAT and graphene oxide nanocomposites, targeting packaging and mulch film applications: characterization, biodegradation and ecotoxicity

• Grant number: 22/06541-2
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: November 01, 2022
• End date: October 31, 2024
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Nonmetallic Materials
• Principal Investigator: Guilhermino José Macêdo Fechine
• Grantee: Patrícia Moraes Sinohara Souza
• Host Institution: Instituto Mackenzie de Pesquisas em Grafeno e Nanotecnologias. Universidade Presbiteriana Mackenzie (UPM). Instituto Presbiteriano Mackenzie. São Paulo , SP, Brazil

Abstract

This research project proposes the study of PBAT nanocomposites with graphene oxide, for use in food packaging, and PBAT nanocomposites with graphene oxide and carbon black, for application in mulch films, aiming at improving mechanical and barrier properties, parameters that are important to make the PBAT polymer viable as a biodegradable alternative to conventional plastics and to reduce the volume of waste to be disposed of in sanitary landfills. Graphene oxide, after synthesized, will be characterized by means of Raman Spectroscopy, Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA), X-Ray Photoelectronic Spectroscopy (XPS), X-Ray Diffraction, Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM). The nanocomposites will be produced by mixing in the melt, by extrusion, and later characterized in terms of gas barrier, mechanical, and light transmission properties. The morphology will be evaluated by X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) techniques. The thermal properties will be analyzed using Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA). From the results of the nanocomposites characterization, a formulation aimed at application in packaging and a formulation aimed at application in mulch film will be selected for the analysis of biodegradation to be carried out in accordance with the ASTM D5988 standard. Bioassays with Folsomia candida and Allium cepa will be used to evaluate possible ecotoxicological impacts on the soil. In the bioassay with Allium cepa, the endpoints of cytotoxicity, genotoxicity, and mutagenicity will be evaluated in soil solubilized samples prepared during biodegradation. Using the Folsolmia candida bioassay, the reproduction endpoint will be evaluated after direct exposure of the organisms to the soil throughout the different periods of biodegradation. This project counts on the collaboration of renowned national and international researchers, specializing in polymeric film processing by co-extrusion (Prof. João Maia, Case Reserve Western University, USA) and ecotoxicity (Prof. Maria Aparecida Marin-Morales, UNESP - Rio Claro).