Effect of textile waste on thermal and mechanical properties of polymer composites

With the development of industry, the disposal and/or recovery of the large amounts of solid waste generated has become increasingly important, particularly with the growing awareness of environmental issues. Solid textile wastes (cotton, polyester, viscose, scraps, etc.) produced in the textile industry one of Turkey's leading sectors constitute a major component of this problem, as they cannot be effectively recycled. Due to the difficulty of recycling, most of these wastes are either discarded or incinerated. Although efforts have been made to reuse or valorize textile waste, such practices generally remain limited to low-value applications such as road fillers, cleaning cloths, or rags. In this study, the effects of textile waste additives and their types on plasticizer diffusion as well as on the thermal and mechanical stability of p-PVC/textile waste composite films during thermal treatment processes were investigated. For this purpose, plastisol pastes were first prepared, air bubbles were removed, and small portions of the plastisols were cast onto glass surfaces to form films with a thickness of 150 μm. These films were then gelled in an oven at 160 °C for 15 minutes to obtain plastigel films. The films were analyzed using UV spectroscopy to monitor polyene formation kinetics and calculate activation energies. Structural changes in the materials were examined via Fourier Transform Infrared (FT-IR) spectroscopy. Diffusion coefficients and activation energies related to plasticizer migration were calculated. Thermogravimetric analysis (TGA) was performed to determine the mass variation of the samples as a function of temperature over time. Dioctyl terephthalate (DOTP) was used as the plasticizer, calcium–zinc stearate (CaSt₂–ZnSt₂) mixtures and epoxidized soybean oil (EPSO) were employed as synergistic thermal stabilizers, and cotton, polyester, viscose, textile dust waste, and leather waste were incorporated as additives. The aim of this study was twofold: to valorize textile waste fibers such as cotton, polyester, viscose, textile dust, and leather waste—which pose significant disposal problems after production—and to enhance the performance of PVC-textile waste composites by mitigating structural degradation that occurs during the thermal degradation process of PVC, ultimately contributing to improved PVC applications.