Separation and recycling of cotton/polyester textile waste: an approach using ionic liquids and deep estectic solvents

• Grant number: 25/01313-0
• Support Opportunities: Scholarships in Brazil - Doctorate
• Start date: July 01, 2025
• End date: February 28, 2029
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Nonmetallic Materials
• Principal Investigator: Sandra Andrea Cruz
• Grantee: Isabelly Bertochi Veroneze
• Host Institution: Centro de Ciências Exatas e de Tecnologia (CCET). Universidade Federal de São Carlos (UFSCAR). São Carlos , SP, Brazil
• Associated research grant: 13/07296-2 - CDMF - Center for the Development of Functional Materials, AP.CEPID

Abstract

The accumulation of textile waste in the environment has become a growing concern in recent years. The use of mixed fabrics, made up of natural and synthetic fibers, is one of the main factors exacerbating this problem. However, the mechanical recycling of cotton/polyester fabrics faces major challenges due to the incompatible thermal properties of these materials. To mitigate this problem, separation steps followed by recycling have been explored as a strategy to promote a circular economy. The use of ionic liquids and deep eutectic solvents has shown promise in the separation of cotton blended fabrics, especially through their solubilization. However, aspects such as the process parameters - including time, temperature and the type of anion used - as well as the predictability of solubilization based on molecular dynamics and the Hansen sphere model, are still little explored in the literature. As well as the use of functional molecules, such as carbodiimide, in the polyester regeneration process. Thus, this proposal aims to (1) characterize cotton/polyester blended fabrics in different proportions, (2) separate the components of these fabrics using different types of solvents, such as ionic liquids and deep eutectic solvents, and investigate the parameters associated with this process, (3) to recover each of these materials for the generation of higher value-added products, using enzymatic hydrolysis and carbodiimide on the previously separated cotton and polyester waste, respectively. The main objective is to develop an efficient method for separating cotton/polyester fabrics, thus proposing a sustainable and technically viable solution for reusing these materials.