An overview on the recycling of waste poly(vinyl chloride)

Abstract

Polyvinyl chloride (PVC) is one of the most important plastics derived from petroleum, which have been extensively used almost in everyday life since last few decades due to its superior...

Recent Advancements in Pyrolysis of Halogen-Containing Plastics for Resource Recovery and Halogen Upcycling: A State-of-the-Art Review

“…The exploration of techniques for removing toxic chemicals from waste halogen-plastics has been particularly investigated in recent years. The specific discussion on the recycling of PVC by mechanical and chemical treatments have been proposed recently. ,− A substantial portion of the literature discusses the realm of e-waste recycling, with a particular emphasis on waste PCBs. − As depicted in Figure S4, our previous studies have specifically discussed the chemical recycling of PVC and brominated-thermoplastics, respectively. − However, there remains a scarcity of focus on the recovery of fuel and chemicals from specific halogen-plastics and the upcycling of halogens. The concept of “transforming pollutants into resources” has considerable significance in alleviating environmental burdens and realizing the valorization of halogen-plastics .…”

Precise activation of C–C bonds for recycling and upcycling of plastics

“…The challenges associated with plastic upcycling arise not only from the activation of C aliph –C aliph bonds but also from the poisoning and deactivation of active sites caused by the presence of unmanageable chlorine elements in the feedstock, such as polyvinyl chloride (PVC). 127–130 For instance, Pidko et al illustrated through a DFT study that the presence of Cl atoms in polyolefins significantly inhibits the performance of catalysts. The Cl atoms can form stable molecular complexes with the catalyst, thereby increasing the energy barrier for the activation of C–H bonds as the initial step.…”

“…These products can serve as precursors for multifunctional carbon materials or be degraded into small molecules. 127 (2) The Cl-transfer strategy involves converting the chlorine element in PVC into Cl-containing organic and inorganic salts. 128,129,132,133 The dechlorinated polyethylene (PE)-like polymer can then be further cleaved into value-added short-chain alkanes.…”

“…It is widely recognized that the degradation of waste plastic involves not only the activation of C aliph –C aliph and C aliph –C Cl bonds but also the significant role played by the activation of C aliph –C arom (sp 2 –sp 3 hybridization) bonds. 16,92,127,139,140 Aromatic polymers including polystyrene (PS), polycarbonate (PC), and phenol formaldehyde resin (PF) contain benzene ring groups and are widely used due to their colorlessness, stability, and hardness. 139 Therefore, the exploration of recycling or upcycling aromatic plastic waste into aromatic compounds through the activation of C aliph –C arom bonds has sparked widespread research interest.…”

Poly(ionic liquid)s: an emerging platform for green chemistry

“…Converting to carbon materials. Carbon materials usually feature a large surface area with open pore structures, excellent chemical stability, and abundant oxygen-containing surface functionalities, exhibiting great promise in many areas, such as gas adsorption, energy storage and conversion, 247,253,254 catalysis, and water treatment. In particular, the introduction of heteroatoms (such as N) to form doped carbon has been demonstrated to be a versatile tool for boosting the application performance of carbon materials.…”