Dechlorination of poly(vinyl chloride): thermal benchmarks and complementary non-thermal pathways toward sustainable recycling

Abstract

Poly(vinyl chloride) (PVC), one of the most widely produced synthetic polymers worldwide, is extensively used in construction, packaging, electrical insulation, and medical applications owing to its low cost, versatility, and durability. However, at the end-of-life stage, the high chlorine content of PVC poses significant challenges, including equipment corrosion, toxic gas emission, and environmental contamination during disposal and recycling processes. Consequently, dechlorination strategies have been intensively investigated as a key step toward PVC recycling and upcycling. While conventional thermal approaches are effective, they generally require the maintenance of high temperatures, often under high pressures that necessitate specially engineered reaction vessels, resulting in high energy input and frequently accompanied by undesirable byproducts. To address these limitations, non-thermal dechlorination methods—such as photocatalytic, catalytic, mechanochemical, and electrochemical processes—have recently attracted growing attention due to their operation under milder conditions, improved byproduct controllability, and potential for selective chlorine removal. In this review, recent advances in non-thermal dechlorination of PVC are systematically examined, with an emphasis on reaction mechanisms, process efficiency, and the properties of dechlorinated products. By comparing different non-thermal approaches, this work highlights their advantages, limitations, and future prospects, underscoring their potential as enabling technologies for sustainable PVC recycling and circular polymer economies.