Themed collection Polymer Upcycling

Blair Brettmann, Marco A. Fraga, Monika Gosecka and Natalie Stingelin introduce the cross journal themed collection on Polymer Upcycling.

Bridging the gap between academia and industry in plastic recycling will accelerate innovation and deployment toward solving the global challenge of plastic waste management and establishing net zero carbon society.

This minireview focuses on potential catalytic recycling processes for the production of styrene and other valuable aromatics from polystyrene (PS) waste, and it aims to lay the ground for PS recyclability and long-term sustainable PS production.

The strategies implemented for upcycling thermoset waste are first reviewed, followed by their strengths and weaknesses; lastly, future directions are highlighted.

Materials research relating to bio-based polymers and composites has become the order of the day and several types of research are being undertaken on these materials.

Plastics and microplastics are major environmental pollutants due to wide applications and difficult degradations. Herein, we summarize several studies on degradations of (micro)plastics to value-added products and intermediates via photocatalysis.

Highly adaptable upcycling of waste polyolefins was demonstrated to obtain high-value nitro-containing polycarboxylic acids in high carbon yields.

This work not only inspires environmentally friendly chemical synthesis strategy to fundamentally address fire hazards, additive risks, and plastic pollution, but also paves the way for sustainable lifecycle management of organic polymer materials.

This work presents an integrated approach to industrial decarbonization by converting mixed polyolefin waste into structured carbon with exceptional Joule heating properties, enabling efficient electrified hydrogen production via NH₃ decomposition.

Novel, fully bio-based, and performance-privileged multifunctional polyolefin-like polyester materials with inherent recyclability, exceptional mechanical and barrier properties and ultra-high machinability.

Circular economy and fire-safety of polymers have become the global consensus. A strategy for selectively self-recyclable, highly-transparent and fire-safe polycarbonate is proposed by thermally responsive phosphonium-phosphate.

Photocurable dynamic cross-linkers based on β-amino esters have been successfully synthesized. The direct restoration of such cross-linkers, enabled by a catalyst- and solvent-free protocol, is established for repeated DLP 3D printing.

Conductive materials obtained from blends of polyurethane, PEDOT:PSS and PEG show exceptional stretchability, toughness, and self-healing properties. Moreover, these materials can be recycled, retaining their mechanical and electrical properties.

A controllable catalytic cracking strategy was proposed for the self-evolving recycling of flame-retardant polyurethane.

A new facile and scalable interfacial locking engineering strategy is exploited to endow reversible microcages with infinite chemical recyclability to starting monomers, exceptional durability, high flame-retardant efficiency, and extensive applicability across diverse polymers.

Mechanically strong, self-healing and recyclable rubber-based ionic elastomers for soft robotics hand.

The developed highly efficient and versatile organocatalyst can deconstruct multiple condensation polymers selectively and sequentially into corresponding monomers, while keeping other polymers such as polyolefins or cotton intact.

Reactions of poly(vinyl chloride) (PVC) with a rhodium catalyst and H-donors reveal how reaction conditions can impact the selectivity for chloride removal, with sodium formate showing the highest selectivity for hydrodechlorination.

A simple, single stage process is reported for the creation of a recyclable thermoset material from readily available epoxy resins and aliphatic amines, crosslinked with diboronic esters.

Tandem hydrodechlorination/Friedel–Crafts alkylation of poly(vinyl chloride) (PVC) is achieved using silylium ion catalysts to prepare new styrenic copolymers of polyethylene.

The upcycling of waste polymers into novel materials with high added value is a vital task for modern chemical engineering.

The first working lithium-ion battery containing polymer electrolytes derived from waste poly(ethylene terephthalate) beverage bottles is demonstrated.

Chemical upcycling of plastic wastes into a new low-molecular-weight supramolecular adhesive with excellent performances.

Synergistic photo-driven plastic waste oxidation and CO₂ reduction on Bi₄V₂O₁₁ nanorods with abundant oxygen vacancies.

Bio-based degradable supramolecular plastics with a high fracture strength of 265 MPa and excellent water-resistance are fabricated through complexation of regenerated cellulose with tannic acid, and can be fully degraded under soil in ∼35 days.

Polymeric materials have become an integral part of our society, and their high demand has created a large quantity of polymers that end up in the waste stream.

Pt/SrTiO₃ nanoparticle catalysts have been synthesized by surface organometallic chemistry in solution on a 5 g scale. Pt/SrTiO₃ selectively and repeatedly upcycles isotactic polypropylene into uniform liquid products with M_n ∼ 200 Da.

A four-step method was applied to biomass and waste polysaccharides, obtaining char-based bifunctional catalysts active in CO₂ conversion into cyclic carbonates.

Block copolymers composed of poly(trimethylene carbonate) and polylactide can be processed at ambient temperature under pressure by a reversible pressure-induced phase transition between an ordered (solid) state and a disordered (melt/solid) state.

This study reports the synthesis and characterization of biobased CANs incorporating CF₃-activated aza-Michael bonds and ester groups showing remarkable reprocessing abilities and high activation energy.

For the first time, virgin and waste polyethylene (PE) was upcycled using exclusively free-radical methods into reprocessable, thermally stable, and creep-resistant PE covalent adaptable networks capable of dialkylamino disulfide dynamic chemistry.

Chemical and catalytic upcycling processes could help realize a circular plastics economy, but current models for testing mechanistic hypotheses and designing catalysts remain primitive.

Sustainable red light harvesting has been achieved in recyclable protein–surfactant–chromophores co-assembled bioplastics with high efficiency due to the efficient diffusion of triplet excited chromophores, and oxygen blockage by protein fibers.

Electronic waste (e-waste) recycling is one of the central frameworks of the circular economy.