State of the art in the photochemical degradation of (micro)plastics: from fundamental principles to catalysts and applications

Li, Wenxi; Zhao, Wei; Zhu, Haoyu; Li, Zhijun; Wang, Wanglei

doi:10.1039/d2ta09523h

“…Thus, developing new strategies to chemically deconstruct and repurpose polymers—especially those not previously known to degrade readily—is an area of significant research interest [5–18] . Photodegradation has emerged as a promising strategy for polymer upcycling [19–25] . For example, the Stache group and several others have recently reported the photooxidative degradation of polystyrene to benzoic acid through a hydrogen atom transfer (HAT) mechanism [26–33] .…”

Section: Figurementioning

confidence: 99%

“…[5][6][7][8][9][10][11][12][13][14][15][16][17][18] Photodegradation has emerged as a promising strategy for polymer upcycling. [19][20][21][22][23][24][25] For example, the Stache group and several others have recently reported the photooxidative degradation of polystyrene to benzoic acid through a hydrogen atom transfer (HAT) mechanism. [26][27][28][29][30][31][32][33] Knowles and coworkers have also developed light-driven depolymerizations of hydroxylated polymers through proton-coupled electron transfer (PCET).…”

mentioning

confidence: 99%

Selective Electrocatalytic Degradation of Ether‐Containing Polymers

Hsu,

Ball,

Oh

et al. 2023

Angew Chem Int Ed

2

0

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Leveraging electrochemistry to degrade robust polymeric materials has the potential to impact society's growing issue of plastic waste. Herein, we develop an electrocatalytic oxidative degradation of polyethers and poly(vinyl ethers) via electrochemically mediated hydrogen atom transfer (HAT) followed by oxidative polymer degradation promoted by molecular oxygen. We investigated the selectivity and efficiency of this method, finding our conditions to be highly selective for polymers with hydridic, electron‐rich C−H bonds. We leveraged this reactivity to degrade polyethers and poly(vinyl ethers) in the presence of polymethacrylates and polyacrylates with complete selectivity. Furthermore, this method made polyacrylates degradable by incorporation of ether units into the polymer backbone. We quantified degradation products, identifying up to 36 mol % of defined oxidation products, including acetic acid, formic acid, and acetaldehyde, and we extended this method to degrade a polyether‐based polyurethane in a green solvent. This work demonstrates a facile, electrochemically‐driven route to degrade polymers containing ether functionalities.

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“…Thus, developing new strategies to chemically deconstruct and repurpose polymers—especially those not previously known to degrade readily—is an area of significant research interest [5–18] . Photodegradation has emerged as a promising strategy for polymer upcycling [19–25] . For example, the Stache group and several others have recently reported the photooxidative degradation of polystyrene to benzoic acid through a hydrogen atom transfer (HAT) mechanism [26–33] .…”

Section: Figurementioning

confidence: 99%

Selective Electrocatalytic Degradation of Ether‐Containing Polymers

Hsu,

Ball,

Oh

et al. 2023

Angewandte Chemie

0

View full text Add to dashboard Cite

Leveraging electrochemistry to degrade robust polymeric materials has the potential to impact society's growing issue of plastic waste. Herein, we develop an electrocatalytic oxidative degradation of polyethers and poly(vinyl ethers) via electrochemically mediated hydrogen atom transfer (HAT) followed by oxidative polymer degradation promoted by molecular oxygen. We investigated the selectivity and efficiency of this method, finding our conditions to be highly selective for polymers with hydridic, electron‐rich C−H bonds. We leveraged this reactivity to degrade polyethers and poly(vinyl ethers) in the presence of polymethacrylates and polyacrylates with complete selectivity. Furthermore, this method made polyacrylates degradable by incorporation of ether units into the polymer backbone. We quantified degradation products, identifying up to 36 mol % of defined oxidation products, including acetic acid, formic acid, and acetaldehyde, and we extended this method to degrade a polyether‐based polyurethane in a green solvent. This work demonstrates a facile, electrochemically‐driven route to degrade polymers containing ether functionalities.

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“…1,2 Additionally, their prevalent treatment as “single-use” materials sees them constitute half of all plastic waste at 152 million tons, of which over 60% is discarded or incinerated, while less than 20% is recycled. 1 Not only does this increase pollution in oceans and forests in the form of microplastics, which refers to polymer fragments created by ultraviolet (UV) exposure, 3–5 but it also represents poor resource management in a world with increasingly depleting resources. In response, various coordinated efforts among governments and industry are in development to reduce plastics waste in accordance with sustainable development goals (SDGs).…”

Section: Introductionmentioning

confidence: 99%