Desenvolvimento de nanocompósitos de grafeno a partir de resíduos da indústria têxtil

Abstract

This research focuses on the development of nanocomposites based on reduced graphene oxide (rGO) incorporated into recycled polyamide (PARec), derived from textile industry waste. The main objective of the study was to evaluate the impact of the addition of different concentrations of rGO (0%, 0.1%, 0.5% and 1% in mass fraction) on the mechanical, thermal and morphological properties of PARec. The composites were manufactured by melt extrusion, followed by molding and detailed characterization of the materials. Thermal characterization was conducted using techniques such as thermogravimetry (TG) and differential scanning calorimetry (DSC), revealing a slight increase in thermal stability with the addition of rGO, although the melting and degradation temperatures presented relatively similar values in all samples. FTIR and Raman spectra were used to investigate the chemical interactions between rGO and the PARec matrix, confirming the integration of rGO into the polymeric bonds. The mechanical properties were evaluated by mechanical tests at room temperature. The results showed a significant increase in the elastic modulus and tensile strength, mainly with the inclusion of 0.5% and 1% rGO. The elastic modulus increased by up to 79% at the 1% rGO concentration, demonstrating the potential of the composite for applications requiring greater stiffness and mechanical strength. However, the impact strength decreased with the increase in the rGO concentration, a behavior associated with the greater stiffness of the material and the reduction in the plastic deformation capacity of the polymer matrix. The statistical analysis was performed using the one-way ANOVA method, with a significance level of 5%, and confirmed the significant influence of the addition of rGO on the mechanical properties of the composites. The multiple comparison of means (LSD) revealed that the concentrations of 0.5% and 1% rGO generated statistically significant differences in the performance of the material in relation to PARec without rGO. Based on the results, although rGO represents a sustainable alternative for the industry due to its potential to reduce environmental impact, the relatively high cost of graphene and its derivatives should be considered. This study reinforces the feasibility of integrating nanomaterials into recycled polymers, promoting advances in materials science and contributing to applications in sectors that require materials with greater mechanical strength and thermal stability.