High-toughness polymeric composite bioinspired in the Brazil Nut (Bertholletia excelsa) mesocarp

• Grant number: 21/02810-6
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: December 01, 2021
• End date: February 03, 2022
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Nonmetallic Materials
• Principal Investigator: Mirabel Cerqueira Rezende
• Grantee: Marilia Sonego
• Host Institution: Instituto de Ciência e Tecnologia (ICT). Universidade Federal de São Paulo (UNIFESP). Campus São José dos Campos. São José dos Campos , SP, Brazil

Abstract

Biomimicry studies aim to identify and apply methods developed by nature over billions of years of evolution in solving current problems. In this scope, the mesocarp layer of the Brazil nut's dried fruit (Bertholletia excelsa) has great potential to inspire new tough composites. This impressive biological capsule consists of bundles of fibers with different orientation, creating sandwich structures, with sclereids filling the spaces between them, and a network of voids. In this project, this biological structure will be imitated by overlapping unidirectional glass fiber tapes, with the subsequent addition of poly(vinyl butyral) (PVB) syntactic foam, to replicate bundles of fibers and sclereids, respectively. The voids network will be identified using microtomography tools and reproduced with 3D printing of a polymer with low adhesion to PVB. The bioinspired composite produced will be characterized by Scanning Electron Microscopy (SEM), tensile strength testing, Charpy impact testing, and fracture toughness testing to measure its main mechanical properties and highlight its toughening mechanisms. These results aim to contribute to the area of bioinspired polymeric composites for structural use and the work to be carried out will contribute to the nucleation of this area at the Polymer and Biopolymers Technology Laboratory, in the ICT/UNIFESP. (AU)