Accurate quantification of polyester in textiles through complete depolymerisation and HPLC

The bulk of textile waste is still landfilled or incinerated, despite its components being potentially recyclable. Textile waste, however, requires prior characterisation to produce homogenous feedstocks that can be recycled with current technologies. Available analytical pipelines are not accurate enough to meet the maximum threshold of contaminants tolerated by recycling processes. Complete depolymerisation of several synthetic fibres into their constituting monomers has already been achieved: the resulting mixtures could be characterised through chromatography, providing an accurate fingerprint of the composition of the fibres. The present work describes an analytical method based on this approach to selectively quantify poly(ethylene terephthalate), the most widely used synthetic fibre, through the quantification of its depolymerisation product, terephthalic acid, using high-performance liquid chromatography.