Self-healing by Diels-Alder cycloaddition in advanced functional polymers: A review

Progress in Materials Science, Год журнала: 2022, Номер 131, С. 101001 - 101001

Опубликована: Авг. 23, 2022

The ability of artificial materials to be healed efficiently, mimicking the living organisms, exhibits a great deal potential advantages that can revolutionise operation and maintenance used in various applications. Such self-healable smart have been extensively researched last few decades, leading development different physical chemical synthesis approaches. Among these methods, techniques based on reversible cycloadditions or disulfide bonding provide obvious terms repeatability, which holds prime importance determining commerciality healing approach. This review compiles recent advances field self-healing polymers where is introduced by cycloaddition reactions while focusing mainly Diels-Alder (DA) reaction. DA [4 + 2] reaction diene dienophile pairs are fabricate thermally crosslinked networks. These covalent bonds necessary reversibility matrix impart desired strength polymeric material. There considerable body literature has employed either its own along with other mechanisms polymers. However, lack systematic discussing works makes it difficult for beginner cope advancements this field. Most early studies focused stimuli efficiency but review, we would like explore thermodynamics governing rupture–repair process use advanced spectroscopic study them their applicability thermosets, epoxy resins, biopolymers, polymer nanocomposites. Novel applications such functional polymers, multifunctional healable outlook future research, opportunities challenges area also discussed.

Язык: Английский

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Dynamic Bonds: Adaptable Timescales for Responsive Materials

Angewandte Chemie International Edition, Год журнала: 2022, Номер 61(50)

Опубликована: Сен. 28, 2022

Dynamic bonds introduce unique properties such as self-healing, recyclability, shape memory, and malleability to polymers. Significant efforts have been made synthesize a variety of dynamic linkers, creating diverse library materials. In addition the development new chemistries, fine-tuning has emerged technique modulate properties. This Review highlights approaches for controlling timescales in Particularly, eight are considered, including urea/urethanes, boronic esters, Thiol-Michael exchange, Diels-Alder adducts, transesterification, imine bonds, coordination hydrogen bonding. emphasizes how structural modifications external factors used tools tune character Finally, this proposes strategies tailoring polymer materials through both kinetic effects modulating bond thermodynamics.

Язык: Английский

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Simple upcycling of virgin and waste polyethylene into covalent adaptable networks: catalyst-free, radical-based reactive processing with dialkylamino disulfide bonds

Journal of Materials Chemistry A, Год журнала: 2022, Номер 10(46), С. 24726 - 24745

Опубликована: Янв. 1, 2022

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

Язык: Английский

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Combining Associative and Dissociative Dynamic Linkages in Covalent Adaptable Networks from Biobased 2,5-Furandicarboxaldehyde

ACS Sustainable Chemistry & Engineering, Год журнала: 2023, Номер 11(6), С. 2334 - 2344

Опубликована: Фев. 2, 2023

Covalent adaptable networks (CAN) emerged as a recent class of polymers that combine the most interesting advantages thermosets and thermoplastics. In this frame, combining different dynamic linkages within polymer network could be an approach to finely tune material properties determine extent their behaviors. Here, we report synthesis novel dually crosslinked CAN in which associative imine dissociative Diels–Alder adducts were both obtained by exploiting chemistry single biobased building block, 2,5-furandicarboxaldehyde (FDC). Thanks favorable chemical environment furan ring linear polyimine based on FDC, very fast coupling with maleimides reactions was reported, leading formation remarkably short times. The sustainable systems shown have behavior in-between those vitrimers CANs, tunable mechanical excellent reprocessability.

Язык: Английский

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Covalent Adaptable Networks Made by Reactive Processing of Highly Entangled Polymer: Synthesis-Structure-Thermomechanical Property-Reprocessing Relationship in Covalent Adaptable Networks

Macromolecules, Год журнала: 2024, Номер 57(6), С. 2756 - 2772

Опубликована: Март 6, 2024

Reactive processing provides a simple approach for grafting dynamic covalent cross-linkers onto linear or branched polymers, resulting in adaptable networks (CANs). We synthesized poly(n-hexyl methacrylate) (PHMA) CANs from neat, entangled PHMA using radical-based reactive to graft the cross-linker called BiTEMPS methacrylate (BTMA) between side chains. By tuning BTMA loading, we achieved range of cross-link densities and characterized how stress relaxation, elevated-temperature creep, reprocessability are affected by density. The cross-links chains allowed novel comparison our reversible, polymers described sticky reptation theory, which long-time relaxation occurs unraveling backbone entanglements, process enabled dissociation subsequent exchange side-chain "stickers." observed two regimes that required their fitting combination stretched exponential decay functions extract pertinent parameters. apparent activation energies creep viscosity same within experimental uncertainty these CANs, verifying shared mechanisms governing temperature dependence viscoelastic responses, independent CAN Notably, made linking ∼50–60% those reported previously with chain backbones. These outcomes demonstrate importance synthesis-structure-property-reprocessing relationships may be various methods varying position incorporation structure.

Язык: Английский

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Catalyst‐Free α‐Acetyl Cinnamate/Acetoacetate Exchange to Enable High Creep‐Resistant Vitrimers

Angewandte Chemie International Edition, Год журнала: 2024, Номер 63(20)

Опубликована: Март 16, 2024

Vitrimers represent an emerging class of polymeric materials that combine the desirable characteristics both thermoplastics and thermosets achieved through design dynamic covalent bonds within polymer networks. However, these are prone to creep due inherent instability bonds. Consequently, there pressing demands for development robust stable chemistries. Here, we report a catalyst-free α-acetyl cinnamate/acetoacetate (α-AC/A) exchange reaction develop vitrimers with remarkable resistance. Small-molecule model studies revealed α-AC/A occurred at temperatures above 140 °C in bulk, whereas 120 °C, this was absent. For demonstration case polymers, copolymers derived from common vinyl monomers were crosslinked terephthalaldehyde produce tunable thermal mechanical performance. All resulting exhibited high stability, especially terms resistance while retaining commendable reprocessability when subjected temperatures. This work showcases as novel chemistry capable imparting stability cross-linked

Язык: Английский

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Novel covalent adaptable networks (CANs) of ethylene/1-octene copolymers (EOCs) made by free-radical processing: comparison of structure–property relationships of EOC CANs with EOC thermosets

Polymer Chemistry, Год журнала: 2023, Номер 14(31), С. 3621 - 3637

Опубликована: Янв. 1, 2023

Various ethylene/1-octene copolymers were upcycled into reprocessable covalent adaptable networks to study structure–property relationships relative their thermoset counterparts.

Язык: Английский

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Reprocessable Covalent Adaptable Networks via Free-Radical Polymerization with an Aromatic Disulfide Cross-Linker

ACS Applied Polymer Materials, Год журнала: 2024, Номер 6(15), С. 9209 - 9218

Опубликована: Июль 22, 2024

Aromatic disulfides have seen widespread use in covalent adaptable networks (CANs), though previous studies exclusively used step-growth methods to integrate them into CANs. Here, we describe a case which an aromatic disulfide-based cross-linker, bis(4-methacryloyloxyphenyl) disulfide, also called BiPheS methacrylate or BPMA, is incorporated CAN by nonstep-growth polymerization. Free-radical copolymerization of n-hexyl with 5 mol % BPMA results exhibits full recovery cross-link density and thermomechanical properties across multiple reprocessing cycles. The rubbery-plateau storage modulus directly proportional absolute temperature, characteristic constant density, even at temperatures where the reprocessable. Indeed, BPMA-based thus associative dynamic character, up least 200 °C, enabling it be elevated-temperature applications without risk loss network character. Under 3.0 kPa shear stress, almost total arrest creep 180 °C major suppression its temperature overcoming potential Achilles' heel associated Thus, integration CANs free-radical polymerization provides facile route produce recyclable that maintain character very high contributing polymer sustainability. Finally, determined Arrhenius apparent activation energy ∼100 kJ/mol for stress relaxation viscosity. This value differs substantially from bond dissociation but agrees alpha-relaxation poly(n-hexyl methacrylate) (PHMA). indicates dependence these viscoelastic responses our associative-type defined cooperative segmental mobility PHMA, makes 95 CAN.

Язык: Английский

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Extrudable, robust and recyclable bio-based epoxy vitrimer via tailoring the topology of a dual dynamic-covalent-bond network

Polymer, Год журнала: 2023, Номер 289, С. 126487 - 126487

Опубликована: Ноя. 15, 2023

Язык: Английский

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BiTEMPS methacrylate dynamic covalent cross-linker providing rapid reprocessability and extrudability of covalent adaptable networks: high-yield synthesis with strong selectivity for disulfide linkages

Polymer Chemistry, Год журнала: 2024, Номер 15(21), С. 2167 - 2176

Опубликована: Янв. 1, 2024

A dialkylamino disulfide-based dynamic covalent cross-linker (BTMA) was synthesized with high purity and selectivity for disulfides used to produce rapidly reprocessable extrudable adaptable networks n -hexyl methacrylate.

Язык: Английский

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