Polymer Chemistry, Journal Year: 2023, Volume and Issue: 15(4), P. 321 - 331
Published: Dec. 16, 2023
Herein, we exploit chemical amplification to release –OH groups in dynamic covalent photopolymers on-demand. Via a single photon event, cascade of reactions occurs, which allows the polymers flow through thermo-activated transesterification.
Language: Английский
European Polymer Journal, Journal Year: 2024, Volume and Issue: 205, P. 112718 - 112718
Published: Jan. 2, 2024
In the contemporary era, novel manufacturing technologies like additive (AM) have revolutionized different engineering sectors including biomedical, aerospace, electronics, etc. Four-dimensional (4D) printing aka AM of smart materials is gaining popularity among scientific community, which has excellent ability to make soft structures such as robots, actuators, and grippers. These are developed by applying various stimuli pH, temperature, magnetic field, many combinations onto materials. Stimuli in 3D permit shape-morphing behaviors bending, twisting, folding, swelling, rolling, shrinking, origami, or locomotion. A wide variety can be fabricated through incorporation hard particles into resulting magneto-active (MASMs). With this integration, magneto-thermal coupling actuation allows diverse magneto-deformations, facilitating development personalized devices that capable enhanced deformation. review, guidelines provided on for MASMs polymers (MAPs), composites, hydrogels (MAHs) booming flexible wearable biomimetic devices. Moreover, 3D-printed robotics an outstanding capacity adapt complicated situations advanced actuating applications. Finally, some current challenges emerging areas exciting technology been proposed. Lastly, it anticipated technological advancements developing intelligent will a significant impact design real-world
Language: Английский
Citations
74
Advanced Functional Materials, Journal Year: 2024, Volume and Issue: unknown
Published: June 29, 2024
Abstract Epoxy resins‐based engineering plastics are indispensable in the global economy, but they have created a serious waste crisis caused by their chemical cross‐linked networks. To solve this problem, current strategies often require assistance of catalysts or solvents at expense thermal and mechanical performance. In work, high‐performance epoxy resin featuring dynamic ester disulfide bonds (TDS) is reported, which exhibits higher properties than common plastics, i.e., tensile strength modulus 66.6 MPa 2.63 GPa, flexural 103.2 3.52 glass transition temperature ( T g ) 133 °C. Moreover, reversible transformation between aromatic thiyl radicals endows TDS with autonomous visualization damage healing. addition, harmonious interplay bonds‐promoted tertiary amine accelerated topological network rearrangements, enabling to easily reshape weld. Specifically, can be completely degraded pure water 200 °C without any catalyst, products directly re‐polymerized achieve green closed‐loop recycling. This work proposes simple economical strategy for development resin‐based cutting‐edge that both functional sustainable.
Language: Английский
Citations
16
Angewandte Chemie International Edition, Journal Year: 2024, Volume and Issue: 63(20)
Published: March 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
Language: Английский
Citations
11
Journal of the American Chemical Society, Journal Year: 2024, Volume and Issue: 146(19), P. 13367 - 13376
Published: May 2, 2024
The use of internal catalysts has emerged as a pivotal design principle to facilitate dynamic exchanges within covalent adaptable networks (CANs). Polybenzoxazines, specifically, have shown considerable potential in generating vitrimers through thermally induced transesterification reactions catalyzed internally by tertiary amines. This study aims investigate the chemical complexities benzoxazine vitrimers. To achieve this, model molecules using various phenolic acids and amino-alcohol derivatives were synthesized precursors. structure these was fully elucidated nuclear magnetic resonance (NMR). Differential scanning calorimetry (DSC) rheology experiments evidenced accelerated network formation precursors due presence aliphatic −OH groups. Thermogravimetric analysis coupled with microcomputed gas chromatography (TGA-μGC) used provide evidence reactions. results showed that spatial proximity between amine hydroxyl groups significantly enhances rate exchange, attributed neighboring group participation (NGP) effect. Interestingly, kinetic complementary NMR techniques revealed thermal latency toward its opening is needed trigger exchange. highlights crucial role steric hindrance basicity promoting exchange an system.
Language: Английский
Citations
10
Progress in Polymer Science, Journal Year: 2024, Volume and Issue: unknown, P. 101890 - 101890
Published: Sept. 1, 2024
Language: Английский
Citations
10
Nano Energy, Journal Year: 2024, Volume and Issue: 122, P. 109288 - 109288
Published: Jan. 21, 2024
Language: Английский
Citations
8
Advanced Materials, Journal Year: 2024, Volume and Issue: 36(21)
Published: April 5, 2024
Abstract Dynamically crosslinked polymers (DCPs) have gained significant attention owing to their applications in fabricating (re)processable, recyclable, and self‐healable thermosets, which hold great promise addressing ecological issues, such as plastic pollution resource scarcity. However, the current research predominantly focuses on redefining and/or manipulating geometries while replicating bulk properties. Given inherent design flexibility of dynamic covalent networks, DCPs also exhibit a remarkable potential for various novel through postsynthesis reprogramming In this review, recent advancements strategies that enable transform properties after synthesis are presented. The underlying mechanisms associated material overviewed mainly three distinct strategies, namely latent catalysts, material‐growth, topology isomerizable networks. Furthermore, mutual relationship impact these when integrated within one system discussed. Finally, application prospects relevant issues necessitating further investigation, along with solutions analyzed.
Language: Английский
Citations
6
Advanced Functional Materials, Journal Year: 2023, Volume and Issue: 34(2)
Published: Sept. 28, 2023
Abstract The utilization of dynamic cross‐linking represents a highly promising approach in addressing the escalating issues plastic pollution and fossil resource consumption. Despite being extensively investigated over past decade, various dynamically cross‐linked polymers (DCPs) predominantly remain confined to realm academic research. To serve as valuable material for practical application, advanced processing is always essential all kinds materials. 3D printing (3DP) enables creation intricate shapes layer‐by‐layer without relying on molds, thus integration 3DP techniques with DCPs holds significant potential enhance expand applicability DCPs. Here, an overview fundamental principles underlying compatible are provided, namely photocuring 3DP, extrusion‐based laser sintering‐based 3DP. Additionally, comprehensive summary representative research works that specifically focus application each respective technique presented. performance mechanism involved corresponding process thoroughly discussed comprehensively reviewed. Finally, existing challenges pertaining further enhancing printability, performance, efficiency, etc., deliberated upon, while proposing directions address these concerns.
Language: Английский
Citations
16
Advanced Materials, Journal Year: 2024, Volume and Issue: unknown
Published: Aug. 3, 2024
Supramolecular adhesion material systems based on small molecules have shown great potential to unite the contradiction between strong and reversibility. However, these suffer from low strength/narrow span, limited designability, single interaction due fewer covalent bond content action sites in molecules. Herein, an ultrahigh-strength large-span reversible adhesive enabled by a branched oligomer controllable self-aggregation strategy is developed. The dense bonds present oligomers greatly enhance strength without compromising resulting exhibits of ≈140 times, switching ultra-strong tough (5.58 MPa 5093.92 N m
Language: Английский
Citations
5
ACS Macro Letters, Journal Year: 2023, Volume and Issue: 12(11), P. 1536 - 1542
Published: Nov. 1, 2023
The industrial implementation of covalent adaptable networks hinges on the delicate task achieving rapid bond exchange activation at specific temperatures while ensuring a sufficiently slow working to avoid irreversible deformation. In this pursuit, latent catalysts offer potential solution, allowing for spatiotemporal control dynamic in vitrimer networks. However, nature their has led undesired creep deformation after multiple cycles reprocessing. work, we demonstrate that tetraphenylborate tetramethyl guanidinium salt (TPB:TMG) undergoes reversible thermal dissociation, releasing free TMG. This thermally organocatalyst can be readily introduced as an additive industrially relevant materials such disulfide-containing polyurethane (PU) undergo disulfide presence base catalyst. contrast with free-base-catalyzed process, dual benefit adding TPB:TMG preventing lower and also enabling reprocessability PU elevated temperatures. remarkable reversibility activated catalyst allows reprocessing effectively maintaining creep-free state service temperature.
Language: Английский
Citations
11