Simulated degradation of differently manufactured polyester fibres released from laundry

The laundering of synthetic textiles is one of the main sources of microplastics (MPs) in the environment. The wide use of polyester (PES) in the textile industry contributes to its release and persistence since it cannot be easily degraded. The fate of these synthetic microfibers depends on different parameters, but their photodegradation, due to sunlight exposure is considered the most common and effective. Recreating this type of degradation in the lab can be time-consuming and, thus, accelerated protocols may be applied to speed up the degradation. The release and the degradation of PES fibres before and after washing were studied, using an accelerated hydrolytic degradation protocol proposed by Sarno et al (2021). Three different types of polyester textiles were selected, coming from different manufacturing steps: undyed polyester, dyed polyester, a polyester commercial garment. Fibres were prepared for the degradation experiments either by manually cutting the textiles or by washing the textiles in a household washing machine and collecting the released fibres from the drainpipe. Thus, the effect of laundering and manufacturing on PES fibres degradation could be investigated. The degradation progress was observed at three different time points. Analysis of the fibres before and after the degradation was performed by Scanning Electron Microscopy (SEM), micro- FTIR, Pyrolysis- Gas Chromatography-Mass Spectrometry (Py-GC/MS) and High Pressure Liquid Chromatography-High Resolution Mass Spectrometry (HPLC-HRMS). Degradation of the samples was evident, with color, fibre mass loss and PES degradation products levels increasing throughout the procedure. According to SEM, neither textile type nor washing affected the morphology of the degradation pattern. Py-GC-MS analyses showed differences in the pyrolyzates of the distinct types of fibres, while non-target analysis (HPLC-HRMS) revealed the presence of some dyes/ additives, such as 4-nitrophenol and disperse orange 3, only in G-PES and others, such as phenyldiethanolamine and acetoacetanilide, only in D-PES. Also see: https://micro2024.sciencesconf.org/548283/document