Thermally Robust yet Deconstructable and Chemically Recyclable High‐Density Polyethylene (HDPE)‐Like Materials Based on Si−O Bonds DOI Creative Commons
Alayna M. Johnson,

Jeremiah A. Johnson

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(51)

Опубликована: Окт. 30, 2023

Polyethylene (PE) is the most widely produced synthetic polymer. By installing chemically cleavable bonds into backbone of PE, it possible to produce deconstructable PE derivatives; date, however, such designs have primarily relied on carbonyl- and olefin-related functional groups. Bifunctional silyl ethers (BSEs; SiR2 (OR'2 )) could expand scope mimics as they possess strong Si-O facile chemical tunability. Here, we report BSE-containing high-density polyethylene (HDPE)-like materials synthesized through a one-pot catalytic ring-opening metathesis polymerization (ROMP) hydrogenation sequence. The crystallinity these can be adjusted by varying BSE concentration or steric bulk Si-substituents, providing handles control thermomechanical properties. Two methods for recycling HDPE are introduced, including circular approach that leverages acid-catalyzed bond exchange with 1-propanol. Additionally, despite fact starting were chain-growth (ROMP), show recover molar mass dispersity recycled products using step-growth formation exchange, generating high molecular weight mechanical properties similar commercial HDPE.

Язык: Английский

Cleavable Comonomers for Chemically Recyclable Polystyrene: A General Approach to Vinyl Polymer Circularity DOI

Gavin R. Kiel,

David Lundberg,

Elisabeth Prince

и другие.

Journal of the American Chemical Society, Год журнала: 2022, Номер 144(28), С. 12979 - 12988

Опубликована: Июнь 28, 2022

Many common polymers, especially vinyl are inherently difficult to chemically recycle and environmentally persistent. The introduction of low levels cleavable comonomer additives into existing polymerization processes could facilitate the production deconstructable recyclable variants with otherwise equivalent properties. Here, we report thionolactones that serve as for chemical deconstruction recycling polymers prepared through free radical polymerization, using polystyrene (PS) a model example. Deconstructable PS different molar masses (∼20-300 kDa) bearing varied amounts statistically incorporated thioester backbone linkages (2.5-55 mol %) can be selectively depolymerized yield well-defined thiol-terminated fragments (<10 suitable oxidative repolymerization generate recycled nearly identical mass parent material, in good yields (80-95%). A theoretical is provided generalize this memory effect. Notably, thermomechanical properties 2.5 % its product similar those virgin PS. were also shown effective cross-linked styrenic copolymer polyacrylate, suggesting comonomers may offer general approach toward circularity many (co)polymers.

Язык: Английский

Процитировано

98
Carbon-to-nitrogen single-atom transmutation of azaarenes DOI
Jisoo Woo, Colin Stein, Alec H. Christian

и другие.

Nature, Год журнала: 2023, Номер 623(7985), С. 77 - 82

Опубликована: Ноя. 1, 2023

Язык: Английский

Процитировано

83
Practical and General Alcohol Deoxygenation Protocol DOI Creative Commons
Oliver P. Williams, Alyah F. Chmiel, Myriam Mikhael

и другие.

Angewandte Chemie International Edition, Год журнала: 2023, Номер 62(18)

Опубликована: Фев. 25, 2023

Herein, we describe a practical protocol for the removal of alcohol functional groups through reductive cleavage their benzoate ester analogs. This transformation requires strong single electron transfer (SET) reductant and means to accelerate slow fragmentation following substrate reduction. To accomplish this, developed photocatalytic system that generates potent from formate salts alongside Brønsted or Lewis acids promote reduced intermediate. deoxygenation procedure is effective across structurally electronically diverse alcohols enables variety difficult net transformations. no precautions exclude air moisture remains efficient on multigram scale. Finally, can be adapted one-pot benzoylation-deoxygenation sequence enable direct deletion. Mechanistic studies validate role acidic additives key C(sp

Язык: Английский

Процитировано

41
Self-powered photocatalytic system fabricated by bifunctional coordination polymers DOI
Qiang Zhang, Chao Huang, Yue Zhang

и другие.

Chemical Engineering Journal, Год журнала: 2024, Номер 482, С. 148854 - 148854

Опубликована: Янв. 21, 2024

Язык: Английский

Процитировано

18
Progress in ATRP-derived materials for biomedical applications DOI Creative Commons
Mohsen Khodadadi Yazdi,

Payam Zarrintaj,

Mohammad Reza Saeb

и другие.

Progress in Materials Science, Год журнала: 2024, Номер 143, С. 101248 - 101248

Опубликована: Фев. 11, 2024

Язык: Английский

Процитировано

17
Mechanism-Guided Discovery of Cleavable Comonomers for Backbone Deconstructable Poly(methyl methacrylate) DOI
Kwangwook Ko,

David Lundberg,

Alayna M. Johnson

и другие.

Journal of the American Chemical Society, Год журнала: 2024, Номер 146(13), С. 9142 - 9154

Опубликована: Март 25, 2024

The development of cleavable comonomers (CCs) with suitable copolymerization reactivity paves the way for introduction backbone deconstructability into polymers. Recent advancements in thionolactone-based CCs, exemplified by dibenzo[c,e]-oxepine-5(7H)-thione (DOT), have opened promising avenues selective deconstruction multiple classes vinyl polymers, including polyacrylates, polyacrylamides, and polystyrenics. To date, however, no thionolactone CC has been shown to copolymerize methacrylates an appreciable extent enable polymer deconstruction. Here, we overcome this challenge through design a new class benzyl-functionalized thionolactones (bDOTs). Guided detailed mechanistic analyses, find that radical-stabilizing substituents bDOTs enables markedly increased tunable methyl methacrylate (MMA). Through iterative optimizations molecular structure, specific bDOT, F-p-CF3PhDOT, is discovered efficiently MMA. High molar mass deconstructable PMMA-based copolymers (dPMMA, Mn > 120 kDa) low percentages F-p-CF3PhDOT (1.8 3.8 mol%) are prepared using industrially relevant bulk free radical conditions. thermomechanical properties dPMMA similar PMMA; former degrade fragments (<6.5 under mild aminolysis This work presents first example ring-opening capable nearly random MMA without possibility cross-linking provides workflow mechanism-guided future.

Язык: Английский

Процитировано

16
A Photoinduced Dual‐Wavelength Approach for 3D Printing and Self‐Healing of Thermosetting Materials DOI
Zhiheng Zhang, Nathaniel Corrigan, Cyrille Boyer

и другие.

Angewandte Chemie International Edition, Год журнала: 2021, Номер 61(11)

Опубликована: Дек. 3, 2021

Vat photopolymerization-based 3D printing techniques have been widely used to produce high-resolution thermosetting materials. However, the lack of repairability these thermosets leads production waste. In this study, reversible addition fragmentation chain transfer (RAFT) agents are incorporated into resin formulations allow visible light (405 nm) mediated materials with self-healing capabilities. The process is based on reactivation RAFT agent embedded in under UV (365 nm), which enables reformation polymeric network. can be performed at room temperature without prior deoxygenation. impact type and concentration polymer network healing efficiency explored. Resins containing enable properties, broadening scope future applications for various fields.

Язык: Английский

Процитировано

63
Dynamic Sustainable Polyimide Film Combining Hardness with Softness via a “Mimosa‐Like” Bionic Strategy DOI
Baoquan Wan, Xing Yang,

Xiaodi Dong

и другие.

Advanced Materials, Год журнала: 2022, Номер 35(2)

Опубликована: Окт. 25, 2022

Dielectric polyimides (PIs) are ubiquitous as insulation in electrical power systems and electronic devices. Generally, dynamic polyimide is required to solve irreversible failure processes of or mechanical damage, for example, under high temperature, pressure, field strength. The challenge lies the design molecular structure rigid achieve reversibility. Herein, a low-molecular-weight gene unit designed crosslink with ligase prepare smart film. Interestingly, due variability combinations, films combining hardness softness into three forms via "Mimosa-like" bionic strategy adapt different application scenarios. Meanwhile, have good degradation efficiency, excellent recyclability, can be self-healable, which makes them reuse. Clearly, used preparation ultrafast sensors response time ≈0.15 s corona-resistant 100% recovery. Furthermore, construction carbon-fiber-reinforced composites (CFRCs) has been verified apply worse environment. Nicely, property multiple cycles non-destructive recycle rate carbon fiber (CF) 100%. idea preparing high-strength by crosslinking simple could provide foundation clear case sustainable development polyimides, from perspective Mimosa bionics.

Язык: Английский

Процитировано

62
Backbone-Photodegradable Polymers by Incorporating Acylsilane Monomers via Ring-Opening Metathesis Polymerization DOI
Banruo Huang,

Mufeng Wei,

Emma Vargo

и другие.

Journal of the American Chemical Society, Год журнала: 2021, Номер 143(43), С. 17920 - 17925

Опубликована: Окт. 22, 2021

Materials capable of degradation upon exposure to light hold promise in a diverse range applications including biomedical devices and smart coatings. Despite the rapid access macromolecules with compositions architectures enabled by ring-opening metathesis polymerization (ROMP), general strategy introduce facile photodegradability into these polymers is lacking. Here, we report copolymers synthesized via ROMP that can be degraded cleaving backbone both solution solid states under irradiation 52 W, 390 nm Kessil LED generate heterotelechelic low-molecular-weight fragments. To best our knowledge, this work represents first instance incorporation acylsilanes polymer backbone. Mechanistic investigation process supports intermediacy an α-siloxy carbene, formed 1,2-photo Brook rearrangement, which undergoes insertion water followed cleavage resulting hemiacetal.

Язык: Английский

Процитировано

61
Direct Deamination of Primary Amines via Isodiazene Intermediates DOI
Kathleen J. Berger, Julia L. Driscoll, Mingbin Yuan

и другие.

Journal of the American Chemical Society, Год журнала: 2021, Номер 143(42), С. 17366 - 17373

Опубликована: Окт. 12, 2021

We report here a reaction that selectively deaminates primary amines and anilines under mild conditions with remarkable functional group tolerance including range of pharmaceutical compounds, amino acids, sugars, natural products. An anomeric amide reagent is uniquely capable facilitating the through intermediacy an unprecedented monosubstituted isodiazene intermediate. In addition to dramatically simplifying deamination compared existing protocols, our approach enables strategic applications iminium amine-directed chemistries as traceless methods. Mechanistic computational studies support intermedicacy which exhibits unexpected divergence from previously studied secondary isodiazenes, leading cage-escaping, free radical species engage in chain, hydrogen-atom transfer process involving aliphatic diazenyl intermediates.

Язык: Английский

Процитировано

56