Discontinuous composites of polymer waste: Relationship of surface energy with mechanical properties

• Grant number: 23/08798-3
• Support Opportunities: Regular Research Grants
• Start date: February 01, 2024
• End date: January 31, 2026
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Nonmetallic Materials
• Principal Investigator: Marcos Yutaka Shiino
• Grantee: Marcos Yutaka Shiino
• Host Institution: Instituto de Ciência e Tecnologia (ICT). Universidade Estadual Paulista (UNESP). Campus de São José dos Campos. São José dos Campos , SP, Brazil
• Associated researchers: Alexei Essiptchouk ; Ricardo Gabbay de Souza

Abstract

The use of polymers, along with polymeric composites, has grown (at rates of 5-7% per year) over the years in both durable and short duration goods, these have generated severe environmental problems due to their high volume of discarded waste. In the case of polymeric composites, there is the generation of waste scraps in the cutting process of different dimensions (fibers or fabrics of different sizes), which makes it difficult to reuse them for similar applications, making their disposal inevitable. In view of the losses of mechanical properties due to the short length of the fiber and, consequently, its greater dependence on adhesion in the transfer of load, compared to continuous fiber, this research aims to quantify the losses as a function of adhesion and variation in fiber length, with variations in thermoplastic matrix type in combination with short carbon fibers. The results generated for each combination of materials will also be analyzed by the ratio between mechanical properties and energy intensity of the material, in a more general analysis to indicate potential replacements for virgin materials. Within the main objective, one can cite the challenge of developing short fiber composites (from waste) from thermoplastic waste (development of polymeric blend or recycled polymer), given the great diversity of waste in this category. To achieve the objective, some steps can be highlighted: 1) assessment of the availability of domestic and industrial waste (electronics, packaging, other applications); 2) theoretical and experimental analysis of the compatibility between polymer-polymer-fiber (will involve the evaluation of the surface energy of the materials); 3) obtaining the recycled polymer film via extrusion and 3D printing; 4) processing of short fiber composites (with a strategy via research developed in Process FAPESP 2017-16160-8); 5) energy intensity analysis and comparison with other polymeric commodities and engineering polymers via Life Cycle Analysis (LCA); 6) evaluation of the interface via tensile test (via criteria developed in the research - Process FAPESP 2017-16160-8. The development of the research will provide contributions in the form of approaching the relationship of micromechanical and macromechanical characteristics, which will have the potential to indicate the load transfer efficiency, possible system improvements and material combinations that may be successful. (AU)