Closing the “One Monomer–Two Polymers–One Monomer” Loop via Orthogonal (De)polymerization of a Lactone/Olefin Hybrid

Journal of the American Chemical Society, Год журнала: 2022, Номер 144(5), С. 2264 - 2275

Опубликована: Янв. 27, 2022

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 catalyst employed, affording two totally different classes polymeric materials from this single monomer: P(BiL=)ROP via functionalized olefin) P(BiL=)ROMP ROMP. Intriguingly, thermally robust chemically recyclable under mild conditions (25–40 °C), in presence catalyst, recover cleanly same chain unzipping scission, respectively. In ROP, topological stereochemical controls have been achieved structures characterized. Furthermore, intact functional group during (i.e., double bond lactone ROMP) is utilized for postfunctionalization tuning materials' thermal mechanical performances. The impressive depolymerization orthogonality further endows selective ROP/ROMP copolymer physical blend composites into starting monomer.

Язык: Английский

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Covalent Mechanochemistry and Contemporary Polymer Network Chemistry: A Marriage in the Making

Journal of the American Chemical Society, Год журнала: 2023, Номер 145(2), С. 751 - 768

Опубликована: Янв. 4, 2023

Over the past 20 years, field of polymer mechanochemistry has amassed a toolbox mechanophores that translate mechanical energy into variety functional responses ranging from color change to small-molecule release. These productive chemical changes typically occur at length scale few covalent bonds (Å) but require large inputs and strains on micro-to-macro in order achieve even low levels mechanophore activation. The minimal activation hinders translation available materials device applications. challenge inspires core questions yet another control, namely: What are molecular-scale features polymeric material determine extent activation? Further, how do we marry advances chemistry networks with create stress-responsive well suited for an intended application? In this Perspective, speculate as potential match between recent network chemistry, specifically, topologically controlled hierarchical enabled by multi-network architectures mechanically interlocked polymers. Both fundamental applied opportunities unique union these two fields discussed.

Язык: Английский

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Mechanically triggered on-demand degradation of polymers synthesized by radical polymerizations

Nature Chemistry, Год журнала: 2024, Номер 16(7), С. 1184 - 1192

Опубликована: Апрель 12, 2024

Abstract Polymers that degrade on demand have the potential to facilitate chemical recycling, reduce environmental pollution and are useful in implant immolation, drug delivery or as adhesives debond demand. However, polymers made by radical polymerization, which feature all carbon-bond backbones constitute most important class of polymers, proven difficult render degradable. Here we report cyclobutene-based monomers can be co-polymerized with conventional impart resulting mechanically triggered degradability. The cyclobutene residues act mechanophores undergo a ring-opening reaction, causes rearrangement renders polymer chains cleavable hydrolysis under basic conditions. These broadly applicable free controlled polymerizations, introduce functional groups into backbone allow gated degradation high-molecular-weight materials cross-linked networks low-molecular-weight species.

Язык: Английский

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Oxygen, Light, and Mechanical Force Mediated Radical Polymerization Toward Precision Polymer Synthesis

Chemical Communications, Год журнала: 2025, Номер unknown

Опубликована: Янв. 1, 2025

This article highlights the advancements in controlled radical polymerization facilitated by three external regulations of oxygen, light, and mechanical force, outlines future directions polymerization.

Язык: Английский

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Organic Ring-Opening Polymerization Catalysts: Reactivity Control by Balancing Acidity

Macromolecules, Год журнала: 2018, Номер 51(8), С. 2932 - 2938

Опубликована: Апрель 4, 2018

Organocatalysts derived from thioureas and amines exhibit high functional group tolerance extraordinary selectivities for ring-opening relative to chain transesterification. The modest activities of the thiourea/amine catalysts prompted a detailed investigation ureas thiourea with organic bases polymerization lactones. An array or were evaluated assess effect acidity urea (thiourea) basicity base cocatalyst on activity polymerization. These studies reveal that given stronger lead faster rates. For base, observed catalytic is highest when (thio)urea closely matched B–H+. comparable acidity, urea/base catalyst systems are considerably more active than corresponding thiourea/base systems. results consistent two mechanisms: one mediated by deprotonated anions (thio)ureas combined sufficient neutral incapable deprotonating (thio)urea. Opposing trends in reactivity as function maximal acidities protonated (B–H+). findings provide basis understanding cocatalysts well guidelines rational design other acid/base pairs.

Язык: Английский

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Supramolecular Block Copolymers by Seeded Living Polymerization of Perylene Bisimides

Journal of the American Chemical Society, Год журнала: 2019, Номер 141(30), С. 12044 - 12054

Опубликована: Июль 13, 2019

Living covalent polymerization has been a subject of intense research for many decades and culminated in the synthesis large variety block copolymers (BCPs) with structural functional diversity. In contrast, on supramolecular BCPs is still its infancy their generation by living processes remains challenge. Here we report formation two-component seeded properly designed perylene bisimides (PBIs) under precise kinetic control. Our detailed studies thermodynamically kinetically controlled three investigated PBIs, which contain hydrogen-bonding amide side groups imide position chlorine, methoxy, or methylthio substituents 1,7 bay-positions, revealed that these PBIs form metastable H-aggregates, can be transformed into favored J-aggregates seed-induced polymerization. We show here copolymerization trapped states one PBI seeds another leads to chain-growth process from seed termini as confirmed UV/vis spectroscopy atomic force microscopy (AFM). This work demonstrates first time triblock polymer architectures A-B-A B-A-B pattern alternate manner.

Язык: Английский

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Branched and Dendritic Polymer Architectures: Functional Nanomaterials for Therapeutic Delivery

Advanced Functional Materials, Год журнала: 2019, Номер 30(2)

Опубликована: Апрель 10, 2019

Abstract Barriers to therapeutic transport in biological systems can prevent accumulation of drugs at the intended site, thus limiting effect against various diseases. Advances synthetic chemistry techniques have recently increased accessibility complex polymer architectures for drug delivery systems, including branched architectures. This article first outlines concepts, and then defines illustrates all forms polymers highly polymers, hyperbranched dendrimers, branched–linear hybrid polymers. Many new types dendritic continue be reported; however, there is often confusion about how accurately describe these architectures, particularly interdisciplinary field nanomedicine where not researchers in‐depth backgrounds. In this context, present review describes compares different their application a simple easy‐to‐understand way, with aim appealing multidisciplinary audience.

Язык: Английский

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Exploiting Molecular Weight Distribution Shape to Tune Domain Spacing in Block Copolymer Thin Films

Journal of the American Chemical Society, Год журнала: 2018, Номер 140(13), С. 4639 - 4648

Опубликована: Март 9, 2018

We report a method for tuning the domain spacing (Dsp) of self-assembled block copolymer thin films poly(styrene-block-methyl methacrylate) (PS-b-PMMA) over large range lamellar periods. By modifying molecular weight distribution (MWD) shape (including both breadth and skew) PS via temporal control polymer chain initiation in anionic polymerization, we observe increases up to 41% Dsp polymers with same overall (Mn ≈ 125 kg mol–1) without significantly changing morphology or chemical composition final material. In conjunction our experimental efforts, have utilized concepts from population statistics least-squares analysis develop model predicting based on first three moments MWDs. This statistical reproduces values high fidelity (with mean absolute errors 1.2 nm 1.8%) provides novel physical insight into individual collective roles played by MWD determining this property interest. work demonstrates that skew profound influence Dsp, thereby providing an conceptual platform exploiting as simple modular handle fine-tuning films.

Язык: Английский

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General route to design polymer molecular weight distributions through flow chemistry

Nature Communications, Год журнала: 2020, Номер 11(1)

Опубликована: Июнь 18, 2020

Abstract The properties of a polymer are known to be intrinsically related its molecular weight distribution (MWD); however, previous methodologies MWD control do not use design and result in arbitrary shaped MWDs. Here we report precise synthesis protocol for producing targeted with simple use, chemistry agnostic computer-controlled tubular flow reactor. To support the development this protocol, constructed general reactor rules by combining fluid mechanical principles, polymerization kinetics, experiments. ring opening lactide, anionic styrene, metathesis used as model polymerizations develop synthesize profiles. derivation mathematical enables quantitative prediction experimental results, provides tool explore limits any protocol.

Язык: Английский

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Rational Synthesis of Metallo-Cations Toward Redox- and Alkaline-Stable Metallo-Polyelectrolytes

Journal of the American Chemical Society, Год журнала: 2019, Номер 142(2), С. 1083 - 1089

Опубликована: Дек. 17, 2019

Cations are crucial components in emerging functional polyelectrolytes for a myriad of applications. Rapid development this area necessitates the exploration new cations with advanced properties. Herein we describe combination computational and experimental design cobaltocene metallo-cations that have distinct electronic redox One direct outcomes on first synthesis complete set cation derivatives is to discover highly stable cations, which further integrated construct metallo-polyelectrolytes as anion-exchange membranes solid-state alkaline fuel cells. The device performance these under basic oxidative environments competitive many organo-polyelectrolytes.

Язык: Английский

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