Incorporação de algodão pré-consumo em compósitos poliméricos para aplicações têxteis

Abstract

Considered one of the oldest and most profitable industries in the world, the textile industry is also one of the main generators of solid waste due to the environmentally unsustainable practices of fast fashion, which produce large volumes of textile waste. Among these wastes, cotton stands out as a widely used natural fiber. This research proposes the reuse of preconsumer cotton waste (RTCO) in the development of reinforced composites for fashion applications. Although there are studies on composites reinforced with lignocellulosic waste in other sectors, there is a lack of research on the use of RTCO in structural materials applied directly to clothing. Furthermore, the phase inversion technique, commonly used in membrane production, is rarely explored in composite manufacturing. This work seeks to fill this gap by proposing an innovative and sustainable reverse logistics and circular economy approach for the reuse of this waste in fashion. The composites are developed using a polysulfone (PSU) polymer matrix reinforced with RTCO through phase inversion techniques: precipitation by solvent evaporation and precipitation by immersion, to make structural trimmings, which are non-woven fabrics. The preparation began with 10 % PSU dissolved in 90 % N,ndimethylformamide DMF at room temperature (25°C) under stirring for 8 h. After this time, the processed textile waste was added in proportions of 6 %, 12 % and 18 % under continuous stirring for another hour. With the polymer solution spread in the mold, the formation of the PSU/RTCO-I materials occurred after its immersion in a non-solvent bath (distilled water). While for PSU/RTCO-E, the solvent was allowed to evaporate completely in a controlled manner. The SEM results indicated that the PSU/RTCO-I and PSU/RTCO-E composites presented good interfacial interaction between RTCO and PSU and good distribution of the fibers throughout. The PSU/RTCO-E composites presented greater porosity and hydrophilicity, with emphasis on the PSU/RTCO-E 12%, which presented greater elongation. The PSU/RTCOI composites demonstrated more homogeneous surfaces, lower wettability and lower water absorption. XRD analyses confirmed the preservation of type I cellulose and the intensification of peaks with increasing RTCO concentration. The best mechanical results were observed in PSU/RTCO-I 12 % and 18 % of load, therefore, this technique became the most suitable for application as structural trimmings. This research demonstrates the technical feasibility of composites with textile waste via phase inversion and expands the possibilities for waste reuse in the sector.