Three types of seemingly unyielding trade-offs have continued to challenge the rational design for circular polymers with both high chemical recyclability and high-performance properties: depolymerizability/performance, crystallinity/ductility, stereo-disorder/crystallinity. Here, we introduce a monomer strategy based on bridged bicyclic thiolactone that produces stereo-disordered perfectly stereo-ordered polythiolactones, all exhibiting crystallinity full recyclability. These polythioesters...

Polyhydroxyalkanoates (PHAs) have attracted increasing interest as sustainable plastics because of their biorenewability and biodegradability in the ambient environment. However, current semicrystalline PHAs face three long-standing challenges to broad commercial implementation application: lack melt processability, mechanical brittleness, unrealized recyclability, last which is essential for achieving a circular economy. Here we report synthetic PHA platform that addresses origin thermal...

Two well-known low-ceiling-temperature (LCT) monomers, γ-butyrolactone (γ-BL) toward ring-opening polymerization (ROP) to polyester and cyclohexene metathesis (ROMP) poly(cyclic olefin), are notoriously "nonpolymerizable". Here we present a strategy render not only polymerizability of both the γ-BL sites, orthogonally, but also complete orthogonal depolymerization, through creating an LCT/LCT hybrid, bicyclic lactone/olefin (BiL=). This hybrid monomer undergoes between ROP ROMP, depending on...

The design and synthesis of closed-loop recyclable polymers is a promising solution to address the large negative effects plastic pollution problem massive economic loss associated with single-use plastics. We demonstrate that ring-opening polymerization (ROP) 6-alkyl-substituted morpholine-2,5-dione (MDs) leads aliphatic poly(ester-amide)s (PEAs) tunable mechanical properties. controlled ROP these MDs was achieved using benzyl alcohol as an initiator DBU/TU catalyst, affording various PEA...

Abstract Geminal ( gem −) disubstitution in heterocyclic monomers is an effective strategy to enhance polymer chemical recyclability by lowering their ceiling temperatures. However, the effects of specific substitution patterns on monomer's reactivity and resulting polymer's properties are largely unexplored. Here we show that, systematically installing ‐dimethyl groups onto ϵ‐caprolactam (monomer nylon 6) from α ϵ positions, both redesigned lactam ‐nylon 6’s highly sensitive position, with...

Chemical recycling to monomers (CRM) offers a promising closed-loop approach transition from current linear plastic economy toward more sustainable circular paradigm. Typically, this has focused on modulating the ceiling temperature (Tc) of monomers. Despite considerable advancements, polymers with low Tc often face challenges such as inadequate thermal stability, exemplified by poly(γ-butyrolactone) (PGBL) decomposition ∼200 °C. In contrast, floor (Tf)-regulated polymers, particularly those...

Despite considerable recent advances already made in developing chemically circular polymers (CPs), the current framework predominantly focuses on CPs with linear-chain structures of different monomer types. As polymer properties are determined by not only composition but also topology, manipulating topology single-monomer-based CP systems from to architecturally complex could potentially modulate resulting without changing chemical composition, thereby advancing concept monomaterial product...

Abstract Chemical recycling of polymers to monomers presents a promising solution the escalating crisis associated with plastic waste. Despite considerable progress made in this field, primary efforts have been focused on redesigning new produce readily recyclable polymers. In contrast, limited research into potential seemingly “non‐polymerizable” has conducted. Herein, we propose paradigm that leverages “chaperone”‐assisted strategy establish closed‐loop circularity for α, β‐conjugated...

Nanofiltration is widely used in various industries to separate solutes from solvents. To foster a circular plastic economy, establishing closed-loop lifecycle for the membrane materials highly important. In this study, we fabricated recyclable nanofiltration membranes chemically polymers —polyester P(BiL=)ROP and poly(cyclic olefin) P(BiL=)ROMP— using γ-butyrolactone as green solvent. These two distinct were obtained single monomer, which could be recycled back parent exhibiting unique "one...

Polydepsipeptides (PDPs) are strictly alternating copolymers of α-hydroxy acids and α-amino produced via the ring-opening polymerization (ROP) morpholino-2,5-dione derivatives (MDs). They have been used as promising biomaterials for their combined high thermal stability good mechanical properties polyamides well inherent degradability polyesters. ROP MDs is usually carried out at temperatures with metal catalysts or enzymes, less control over polymer molecular weights dispersities. In this...

Poly(3-hydroxyburtyrate) (P3HB) is the simplest but most important member of large biodegradable polyhydroxyalkanoate family. However, bacterial P3HB, a pure isotactic crystalline material, brittle, thus limiting its broad applications. Considering that poly(ε-caprolactone) (PCL) and poly(4-hydroxybutyrate) (P4HB) are much more ductile than here we utilize metal-catalyzed stereoselective copolymerization racemic eight-membered dimethyl diolide (rac-8DLMe) with ε-caprolactone (ε-CL)...

Activating inert sp3 -sp3 carbon-carbon (C-C) bonds remains a major bottleneck in the chemical upcycling of recalcitrant polyolefin waste. In this study, redox mediators are used to activate C-C bonds. Specifically, N-hydroxyphthalimide (NHPI) is as mediator, which oxidized phthalimide-N-oxyl (PINO) radical initiate hydrogen atom transfer (HAT) reactions with benzylic C-H The resulting carbon readily captured by molecular oxygen form peroxide that decomposes into oxygenated bond-scission...

Naturally produced, biodegradable polyhydroxyalkanoates (PHAs) promise more sustainable alternatives to nonrenewable/degradable plastics, but biological PHA's stereomicrostructures are strictly confined isotactic (R)-polymers or copolymers of random sequences. Chemical synthesis via catalyzed ring-opening polymerization (ROP) cyclic (di)esters offers expedient access diverse PHA microstructures, including those with defined comonomer sequences and tacticities. However, the alternating PHAs...

Technologically important thermosets face a long-standing end-of-life (EoL) problem of non-reprocessability, more sustainable solution which has resolved to nascent vitrimers that can merge the robust material properties and reprocessability thermoplastics. However, lifecycle is still finite, as they often suffer from significant deterioration mechanical performance following multiple reprocessing cycles, analogous recycling, show undesired creep under working conditions. To address these...

Abstract Physical blending is an effective strategy for tailoring polymeric materials to specific application requirements. However, physically blended mixed plastics waste adds additional barriers in mechanical or chemical recycling. This difficulty arises from the intricate requirement meticulous sorting and separation of various polymers inherent incompatibility during To overcome this impediment, work furthers emerging single‐monomer – multiple‐materials approach through design a...

Polystyrene (PS) is a widely used thermoplastic polymer, but its very low recycling rate has motivated consideration of chemical conversion strategies to convert waste PS into value-added products. Oxidation methods have been studied, they typically generate benzoic acid, product with relatively market demand. Phenol higher volume that would be an appealing target, no currently exist for the phenol. The repeat unit in closely resembles cumene, primary feedstock produce phenol through Hock...

Within the large poly(3-hydroxyalkanoate) (PHA) family, C3 propionates are much less studied than C4 butyrates, with exception of α,α-disubstituted propionate PHAs, particularly poly(3-hydroxy-2,2-dimethylpropionate), P3H(Me)2P, due to its high melting temperature (Tm ∼ 230 °C) and crystallinity (∼76%). However, inefficient synthetic routes monomer 2,2-dimethylpropiolactone [(Me)2PL] extreme brittleness P3H(Me)2P largely hinder broad applications. Here, we introduce simple, efficient...

Tetrahydropyran (THP) is a five-carbon heterocyclic ether that non-carcinogenic, non-peroxide forming, biodegradable, and economically competitive with tetrahydrofuran (THF) as solvent.