Recycled PET Chemistry (rPET)
topic
Chemical recycling of PET includes glycolysis (EG depolymerisation to BHET oligomers at 190–220°C), methanolysis (DMT recovery), and hydrolysis (TPA recovery). Mechanical recycling re-melts flake, reducing IV by 0.05–0.15 dL/g per cycle due to chain scission. Contaminants (PVC, coloured PET, adhesives) degrade quality. rPET for fibre requires IV ≥ 0.58 dL/g.
Role
rPET chemistry is central to circular economy design in polyester textiles. Understanding degradation mechanisms during recycling is essential for designing recyclable products and setting quality standards for recycled fibre.