Upcycling of polyvinyl chloride to porous carbon for high-performance electromagnetic wave absorption materials

The increasing accumulation of plastic waste, particularly polyvinyl chloride (PVC) plastics containing halogens, has led to severe environmental issues. To achieve environmentally friendly treatment and upcycling of PVC , this study presents a straightforward two-step method for converting PVC into porous carbon materials. First, PVC is subjected to ambient temperature ball milling in a KOH/polyethylene glycol (PEG) system to efficiently remove chlorine atoms (degree of dechlorination up to 93.88 %), yielding a crosslinking precursor. Subsequently, the precursor is carbonized via co-carbonization with K 2 CO 3 , resulting in a layered porous carbon material with a high surface area and abundant micropores and mesopores. This method significantly reduces the emission of the corrosive gas HCl during carbonization while improving the carbon yield. The prepared carbon material exhibits excellent electromagnetic wave (EMW) absorption performance, with a minimum reflection loss (RL) of −47.65 dB at a thickness of 3.5 mm and filler loading of 10 wt%, along with an effective absorption bandwidth (EAB) of 4.96 GHz. This method has the potential to be extended to practical PVC products and represents a new approach to the upcycling of waste PVC.