Rearrangement Of Network Research Articles

Readily Recyclable, Auto-Catalyzed Tung Oil-Derived Vitrimers and Carbon Fiber-Reinforced Composites

The high strength and durability of carbon fiber-reinforced composites (CFRCs) have made them a popular choice in aerospace, civil engineering, and sports equipment. However, the non-degradable resin matrix and non-destructive recycling of carbon fibers present a challenge for their sustainability. To address this issue, we have developed a new type of CFRCs that are readily recyclable and high-performing, using an auto-catalyzed tung oil-derived vitrimer and acid curing agents (TTMA) in combination with bisphenol A epoxy resin (DGEBA) or 4,4′-methylene bis (N,N-di glycidylaniline) (TGDOM). The DGEBA/TGDOM-TTMA networks contain abundant ester bonds, hydroxyl groups, and tertiary amine, which can undergo dynamic transesterification reactions (DTER) at high temperatures, leading to topological rearrangement of cross-linked networks. This results in an epoxy resin matrix with excellent mechanical properties, thermostability, and easy reprocessing, self-healing, and degradation at elevated temperatures. Moreover, the TGDOM-TTMA exhibits good stress relaxation properties due to the high concentrations of hydroxyl and tertiary amine. Additionally, we have found that carbon fibers can be completely recycled from CFRCs using ethanolamine via amidation reaction, with the recycled carbon fibers maintaining nearly 100% of the mechanical properties of the virgin samples. This study offers a sustainable and convenient strategy for designing readily recyclable and high-performance CFRCs, with important implications for the future of composite materials.

Drainage network rearrangement during the formation and segmentation of a Paleogene intraplate half-graben: Insights from fluvial captures records and longitudinal profiles

Rivers play an important role in modifying landscapes through denudation processes, which can be influenced by changes in tectonics, climate and eustasy, causing erosive pulses and river capture events that alter the geometry and topology of the drainage network. Therefore, drainage networks are not static features over time and are modified and rearranged by shifts in their boundary conditions until a state of dynamic equilibrium is reached in the landscape. The region of the Paraíba do Sul Middle Valley (PSMV), in Southeastern Brazil, has important records of captures and recent drainage rearrangements, which show a state of transition in the landscape and, consequently, the reorganization of drainage networks. This region is in the central segment of the Continental Rift of Southeastern Brazil (CRSB), a prominent tectonic feature that can be described as an intraplate half-graben. While fluvial profiles and fluvial gradient indices are valuable tools for studying the landscape evolution, their application to investigate the erosive power of rivers and how the topography of a half-graben affects the rearrangement of the drainage network over geological time is still limited. Specifically, there is a need to explore how the topography of the active border of a half-graben differs from that of the flexural border in terms of river network organization and fluvial erosion patterns. This study aims to characterize the different stages of rearrangements of the drainage network and their relation with the events of formation and segmentation of a half-graben. A total of 21 basins were analyzed in both Fault and Flexural Border sectors, extracting geomorphic parameters, such as slope, drainage area, concavity, χ and ksn. A more specific study was carried out in areas where river captures were recognized as been related to the half-graben formation and segmentation events. The ksn calculated for the main rivers demonstrates that the formation of the rift and its consequent configuration in half-graben granted a greater erosive power for the basins that drained the active fault of the rift, represented by the basins of the Fault Border Sector of the study area. The tectonic events registers in the fluvial system were analyzed using the χ method and the main migration tendency of the dividers was extracted from the difference in the values of this parameter in areas close to the interfluves. With this, it becomes evident that the geometric configuration imposed in the half-graben establishes, from the beginning of the rift phase, an important control on the erosion potential of the rivers located in the active and flexural borders. This control resulted in ancient river captures, currently exposed as inflections in the main river channels towards the local depocenters, thus demonstrating that this type of tectonic event can generate disturbances in the river system that can be observed even today, tens of millions of years after it happened.

Introducing Dynamic Bonds in Light‐based 3D Printing

AbstractLight‐based 3D printing has received significant attention due to several advantages including high printing speed and resolution. Along with the development of new technologies, material design is key for the next generation of light‐based 3D printing. Conventional printable polymeric materials, also known as photopolymers or photoresins, often lead to thermosets–polymer networks cross‐linked by permanent covalent bonds which bring limited adaptability and restricted reprocessability. Dynamic bonds that can reversibly break and reform enable network rearrangement, thereby offering unprecedented properties to the materials such as adaptability, self‐healing, and recycling capabilities. Hence, introducing dynamic bonds into materials for light‐based 3D printing is a promising strategy to further expand and meet the diverse application scenarios of 3D printed multi‐functional materials and moreover meet more demanding sustainable and nature‐inspired design considerations (e.g., adaptability and self‐healing). Herein, an overview of recent advances in dynamic photopolymers for light‐based 3D printing, aiming to bridge these two promising research fields is presented. Importantly, the current challenges are also analyzed and perspectives for further developing dynamic photopolymers for light‐based 3D printing and their potential applications are provided.

Recyclable flame retardant phosphonated epoxy based thermosets enabled via a reactive approach

The development of reusable fire-safe polymers with a prolonged lifetime heralds the switch for a transition towards circular economy. In this framework, we report a novel phosphonated thermoset which is composed of networked phosphonate esters containing both PC and PO bonds. Employing a simple one-pot, two-step synthetic methodology, oxirane groups of the epoxy resin were partially reacted with various amounts of reactive bis H-phosphonate monomer, and cured with a cycloaliphatic hardener to obtain multifunctional thermosets with up to 8% phosphorus (P) content. Though 2.5% P was adequate to achieve good flame retardancy, a concentration > 5% P was necessary for accomplishing material reprocessability and recyclability. These phosphonated thermosets exhibited high Tg (94 °C – 140 °C) and good thermal stability. Fire performance of the thermoset with 2.5% P via cone calorimetry showed effective reduction in the peak heat release rate (pHRR, 75%) and significant inhibition of total smoke production (TSP, 72.5%), which was attributed to the gas and condense phase actions of the phosphonate moieties. This thermoset was explored as a transparent fire-safe coating on wood where an intumescent flame retardant mechanism was observed. The phosphonated thermoset with higher P content (6%) demonstrated excellent damage reparability and thermomechanical reprocessability driven by transesterification induced network rearrangement. This thermoset was used for manufacturing flax fiber reinforced composite, to demonstrate its future application as a polymer matrix for composite materials.

Unconventional floppy network structures in titanate glasses

Annealed titanate glasses are important candidate materials for high-performance electronic components, but their structural response to temperature-induced properties upon thermal annealing remains elusive. Here, using high-energy synchrotron X-ray scattering, high-temperature Raman spectroscopy, and empirical potential structure refinement simulation, we track the structural evolution in situ of a barium dititanate (BaTi2O5) glass upon annealing around and below the glass transition temperature. We find that the network structure is intrinsically floppy, as the network units ([TiOm] polyhedra) themselves and their topological packing can be easily modulated by annealing temperature. The floppy nature of the glassy titanate network challenges the currently well-cognized Rigid-Unit Mode model explaining temperature-driven structural reorganization of prototypical network glasses (e.g., silicate/borate glasses). As temperature increases, the floppy network of BaTi2O5 glass undergoes a non-monotonic, two-stage network rearrangement. After cooling back to room temperature, the distortion of network units is found recoverable whereas the change of network connectivity in the intermedium-range order is irreversible. Simulation ensembles further show the irreversible connectivity change can be ascribed to the local development of crystal-like cationic motifs, which in turn induce excess enthalpy relaxation. Our findings provide an atomic-scale perspective on temperature-dependent structural and enthalpy relaxation of a model titanate glass upon annealing, which are crucial for understanding thermal-related changes in the properties of titanate glasses.

Dual dynamic crosslinking of rubber for enhanced mechanical properties and reconfigurable shape memory behavior

AbstractConstructing dynamic covalent bonds (DCBs) in rubbers provides a promising avenue to resolve the trade‐offs between chemical crosslinking and recyclability. The reinforcement of dynamic covalent networks by nanofilling is widely adopted, which, however, inevitably hinders the exchange reaction of DCBs and network rearrangement due to the restrictions on chain mobility imposed by fillers. To date, the reinforcement of dynamic covalent networks without affecting the dynamic properties remains challenging. In this work, we report a dual dynamic crosslinking strategy by engineering reversible noncovalent bonds into dynamic covalent rubbers to improve mechanical performance and simultaneously maintain desirable malleability and reprocessability. Specifically, dynamic boronic ester‐crosslinked styrene–butadiene rubber is firstly prepared and then modified through triazolinedione (TAD) click reaction. The grafted urazole groups can form hydrogen bond interactions that further aggregate to form clusters and phase‐separation structure in the networks. Due to the reversible nature of hydrogen bonds, they can act in a sacrificial manner to dissipate mechanical energy, leading to a combination of improved strength, modulus and toughness of the networks. More importantly, the hydrogen‐bonded clusters are dissociated at elevated temperatures, enabling the network dynamic properties to be largely preserved. In addition, the dynamic features of the dual crosslinks (hydrogen bonds and boronic esters) endow the TAD‐modified networks with reconfigurable shape memory effect. © 2023 Society of Industrial Chemistry.

Rearrangeability and repackability of a multicast wavelength-space-wavelength elastic optical network

Elastic optical networks (EONs) have been introduced to meet the demands of the rapidly growing Internet. These networks can efficiently keep up with the emerging bandwidth-hungry and highly dynamic services, and can support multicast services using techniques like the path, tree or subtree methods. A multicast wavelength-space-wavelength (M-WSW) network is a switching node architecture for EONs, which adopts the subtree method to support multicast connections. An M-WSW network consists of three node stages in which wavelength, space and wavelength switches are used, respectively. A nonblocking M-WSW network guarantees that any connection between a free input and a free output can always be realized, and studying the nonblockingness of a network has attracted much attention from researchers. Sufficient conditions, in terms of the number of middle space switches, for an M-WSW network to be strict-sense nonblocking (SNB) or wide-sense nonblocking (WSNB) were examined in an earlier study. It is known that SNB networks usually incur a higher hardware cost, for instance, the number of middle space switches, compared to WSNB, rearrangeably nonblocking (RNB), or repackably nonblocking (RPNB) networks. This paper studies the rearrangeability and repackability of M-WSW networks, and derives the sufficient and necessary conditions for an M-WSW network to be RNB (or RPNB). The results show that the derived sufficient conditions for being RNB (or RPNB) require significantly fewer middle switches for SNB and WSNB networks, and the RPNB results require fewer middle switches than those for RNB in most cases.

Microhydration of the Pyrrole Cation (Py+) Revealed by IR Spectroscopy: Ionization-Induced Rearrangement of the Hydrogen-Bonded Network of Py+(H2O)2

Microhydration of heterocyclic aromatic molecules can be an appropriate fundamental model to shed light on intermolecular interactions and functions of macromolecules and biomolecules. We characterize herein the microhydration process of the pyrrole cation (Py+) by infrared photodissociation (IRPD) spectroscopy and dispersion-corrected density functional theory calculations (B3LYP-D3/aug-cc-pVTZ). Analysis of IRPD spectra of mass-selected Py+(H2O)2 and its cold Ar-tagged cluster in the NH and OH stretch range combined with geometric parameters of intermolecular structures, binding energies, and natural atomic charge distribution provides a clear picture of the growth of the hydration shell and cooperativity effects. Py+(H2O)2 is formed by stepwise hydration of the acidic NH group of Py+ by a hydrogen-bonded (H2O)2 chain with NH···OH···OH configuration. In this linear H-bonded hydration chain, strong cooperativity, mainly arising from the positive charge, strengthens both the NH···O and OH···O H-bonds with respect to those of Py+H2O and (H2O)2, respectively. The linear chain structure of the Py+(H2O)2 cation is discussed in terms of the ionization-induced rearrangement of the hydration shell of the neutral Py(H2O)2 global minimum characterized by the so-called "σ-π bridge structure" featuring a cyclic NH···OH···OH···π H-bonded network. Emission of the π electron from Py by ionization generates a repulsive interaction between the positive π site of Py+ and the π-bonded OH hydrogen of (H2O)2, thereby breaking this OH···π hydrogen bond and driving the hydration structure toward the linear chain motif of the global minimum on the cation potential.

Assessment of impaired consciousness using EEG-based connectivity features and convolutional neural networks.

Growing electroencephalogram (EEG) studies have linked the abnormities of functional brain networks with disorders of consciousness (DOC). However, due to network data's high-dimensional and non-Euclidean properties, it is difficult to exploit the brain connectivity information that can effectively detect the consciousness levels of DOC patients via deep learning. To take maximum advantage of network information in assessing impaired consciousness, we utilized the functional connectivity with convolutional neural network (CNN) and employed three rearrangement schemes to improve the evaluation performance of brain networks. In addition, the gradient-weighted class activation mapping (Grad-CAM) was adopted to visualize the classification contributions of connections among different areas. We demonstrated that the classification performance was significantly enhanced by applying network rearrangement techniques compared to those obtained by the original connectivity matrix (with an accuracy of 75.0%). The highest classification accuracy (87.2%) was achieved by rearranging the alpha network based on the anatomical regions. The inter-region connections (i.e., frontal-parietal and frontal-occipital connectivity) played dominant roles in the classification of patients with different consciousness states. The effectiveness of functional connectivity in revealing individual differences in brain activity was further validated by the correlation between behavioral performance and connections among specific regions. These findings suggest that our proposed assessment model could detect the residual consciousness of patients.

Sustainable Bio-Based UV-Cured Epoxy Vitrimer from Castor Oil.

Vitrimers brought new properties in thermosets by allowing their reshaping, self-healing, reprocessing, and network rearrangement without changing structural integrity. In this study, epoxidized castor oil (ECO) was successfully used for the straightforward synthesis of a bio-based solvent-free vitrimer. The synthesis was based on a UV-curing process, which proceeded at low temperatures in the absence of any solvents, and within a short time. Real time Fourier-transformed infrared spectroscopy and photo-DSC were exploited to monitor the cationic photocurable process. The UV-cured polymer networks were able to efficiently undergo thermo-activated bond exchange reactions due to the presence of dibutyl phosphate as a transesterification catalyst. Mechanical properties, thermal resistance, glass transition temperature, and stress relaxation were investigated as a function of the amount of transesterification catalyst. Mechanical properties were determined by both DMTA and tensile tests. Glass transition temperature (Tg) was evaluated by DMTA. Thermal stability was assessed by thermogravimetric analysis, whilst vitrimeric properties were studied by stress relaxation experiments. Overall, the ECO-based vitrimer showed high thermal resistance (up to 200 °C) and good mechanical properties (elastic modulus of about 10 MPa) and can therefore be considered as a promising starting point for obtaining more sustainable vitrimers.

Rearrangement of GUV-confined actin networks in response to micropipette aspiration.

Studies have shown that actin networks to be force sensing, force generating and endowing the mechanical property of cells. Actin networks are capable of these specialized tasks due to their ability to rearrange and assemble into diverse networks via numerous actin binding proteins. However, how different actin networks reorganize under applied forces is not entirely understood. Recently, bottom-up reconstitution has enabled studies where dynamic and phenotypical characteristics of various actin networks can be recreated in an isolated cell-like environment. Here, by creating a giant unilamellar vesicle (GUV)-based cell model encapsulating actin networks, we aim to understand how actin networks rearrange in response to stresses in confined spaces. We reconstitute actin cortex and actin bundles separately and use micropipette aspiration to mechanically perturb and induce stress. Interestingly, we find that, when aspirated, protrusive actin bundles that are otherwise randomly oriented in the GUV lumen collapse and align along the axis of pipette. Furthermore, when uniform cortex-GUVs are aspirated, bleb-like cortex-free membrane is aspirated in the micropipette. These results reveal diverse responses in the rearrangement of actin networks subject to physical forces.

Landscape dynamics and diversification of the megadiverse South American freshwater fish fauna

Landscape dynamics are widely thought to govern the tempo and mode of continental radiations, yet the effects of river network rearrangements on dispersal and lineage diversification remain poorly understood. We integrated an unprecedented occurrence dataset of 4,967 species with a newly compiled, time-calibrated phylogeny of South American freshwater fishes-the most species-rich continental vertebrate fauna on Earth-to track the evolutionary processes associated with hydrogeographic events over 100 Ma. Net lineage diversification was heterogeneous through time, across space, and among clades. Five abrupt shifts in net diversification rates occurred during the Paleogene and Miocene (between 30 and 7 Ma) in association with major landscape evolution events. Net diversification accelerated from the Miocene to the Recent (c. 20 to 0 Ma), with Western Amazonia having the highest rates of insitu diversification, which led to it being an important source of species dispersing to other regions. All regional biotic interchanges were associated with documented hydrogeographic events and the formation of biogeographic corridors, including the Early Miocene (c. 23 to 16 Ma) uplift of the Serra do Mar and Serra da Mantiqueira and the Late Miocene (c. 10 Ma) uplift of the Northern Andes and associated formation of the modern transcontinental Amazon River. The combination of high diversification rates and extensive biotic interchange associated with Western Amazonia yielded its extraordinary contemporary richness and phylogenetic endemism. Our results support the hypothesis that landscape dynamics, which shaped the history of drainage basin connections, strongly affected the assembly and diversification of basin-wide fish faunas.

Characterizing rheological properties and microstructure of thioester networks during degradation.

Covalent adaptable networks are designed for applications including cell and drug delivery and tissue regeneration. These applications require network degradation at physiological conditions and on a physiological timescale with microstructures that can: (1) support, protect and deliver encapsulated cells or molecules and (2) provide structure to surrounding tissue. Due to this, the evolving microstructure and rheological properties during scaffold degradation must be characterized. In this work, we characterize degradation of covalent adaptable poly(ethylene glycol) (PEG)-thioester networks with different amounts of excess thiol. Networks are formed between PEG-thiol and PEG-thioester norbornene using photopolymerization. These networks are adaptable because of a thioester exchange reaction that takes place in the presence of excess thiol. We measure degradation of PEG-thioester networks with L-cysteine using multiple particle tracking microrheology (MPT). MPT measures the Brownian motion of fluorescent probe particles embedded in a material and relates this motion to rheological properties. Using time-cure superposition (TCS), we characterize the microstructure of these networks at the gel-sol phase transition by calculating the critical relaxation exponent, n, for each network with different amounts of excess thiol. Based on the measured n values, networks formed with 0% and 50% excess thiol are tightly cross-linked and elastic in nature. While networks formed with 100% excess are similar to ideal, percolated networks, which have equal viscous and elastic components. MPT measurements during degradation of these networks also measure a non-monotonic increase in probe motility. We hypothesize that this is network rearrangement near the phase transition. We then measure macroscopic material properties including the equilibrium modulus and stress relaxation. We measure a trend in bulk network properties that agrees with the values of n. Elastic modulus and stress relaxation measurements show that networks with 50% excess thiol are more elastic compared to the other two networks. As the amount of excess thiol is increased from 0% to 50%, the networks become more elastic. Further increasing excess thiol to 100% reduces the elastically effective cross-links. We hypothesize that these properties are due to network non-idealities, resulting in networks with 50% excess thiol that are more elastic. This work characterizes dynamic rheological properties during degradation, which mimics processes that could occur during implantation. This work provides information that can be used in the future design of implantable materials enabling both the rheological properties and timescale of degradation to be specified.

Creating glassy states of dicarboxylate-bridged coordination polymers.

We report the direct formation of dicarboxylate-based coordination polymer glasses through thermal dehydration. The rearrangement of the coordination networks caused by dehydration was monitored by in situ powder X-ray diffraction, infrared spectroscopy, and synchrotron X-ray characterizations. The microporosity and mechanical properties of these glasses were investigated.

Impoverishment, hunger, and pandemic: Emergency Aid, the end of the Bolsa Família Benefit, and its replacement, Auxílio Brasil, 2019-2022

This article addresses the political choices made by the Brazilian government concerning conditional cash transfer programs during the covid-19 pandemic. The aim is to analyze how the covid-related Emergency Aid (Auxílio Emergencial), the extinction of the Bolsa Família Program, and the implementation of its replacement, Auxílio Brasil, interacted in the rearrangement and dismantling of Brazil's social protection network in a broader context of a generalized impoverishment of Brazilian workers. The article not only presents a record of these actions, but also offers an interpretative approach that, historically contextualized, can shed light on these actions, which ran parallel to the deepening entrenchment of neoliberal policies in the country.

First-principles study on unidirectional proton transfer on anatase TiO2 (101) surface induced by external electric fields.

The electric field (EF) effect on hydrogen or proton transfer (PT) via hydroxyl groups on an anatase TiO2 (101) surface is examined using first-principles density functional theory and the modern theory of polarization. This study focuses on unidirectional surface PT caused by external EFs at various orientations toward the surface. The preferred PT pathway can change depending on the magnitude and direction of the EF. Detailed analysis reveals that the variation in the energy profile with the EF is significantly different from that determined by the classical electric work of an EF carrying a point charge. The EF effect on the energy profile of the PT is governed by the rearrangement of the chemical bond network at the interface between the water molecules and the surface.

Large-scale assessment of pros and cons of autopsy-derived or tumor-matched tissues as the norms for gene expression analysis in cancers

Normal tissues are essential for studying disease-specific differential gene expression. However, healthy human controls are typically available only in postmortal/autopsy settings. In cancer research, fragments of pathologically normal tissue adjacent to tumor site are frequently used as the controls. However, it is largely underexplored how cancers can systematically influence gene expression of the neighboring tissues. Here we performed a comprehensive pan-cancer comparison of molecular profiles of solid tumor-adjacent and autopsy-derived “healthy” normal tissues. We found a number of systemic molecular differences related to activation of the immune cells, intracellular transport and autophagy, cellular respiration, telomerase activation, p38 signaling, cytoskeleton remodeling, and reorganization of the extracellular matrix. The tumor-adjacent tissues were deficient in apoptotic signaling and negative regulation of cell growth including G2/M cell cycle transition checkpoint. We also detected an extensive rearrangement of the chemical perception network. Molecular targets of 32 and 37 cancer drugs were over- or underexpressed, respectively, in the tumor-adjacent norms. These processes may be driven by molecular events that are correlated between the paired cancer and adjacent normal tissues, that mostly relate to inflammation and regulation of intracellular molecular pathways such as the p38, MAPK, Notch, and IGF1 signaling. However, using a model of macaque postmortal tissues we showed that for the 30 min – 24-hour time frame at 4ºC, an RNA degradation pattern in lung biosamples resulted in an artifact “differential” expression profile for 1140 genes, although no differences could be detected in liver. Thus, such concerns should be addressed in practice.

Retraction Notice: Rearrangement of Electrical Distribution Networks With Optimal Coordination of Grid-Connected Hybrid Electric Vehicles and Wind Power Generation Sources

Retraction Notice: Rearrangement of Electrical Distribution Networks With Optimal Coordination of Grid-Connected Hybrid Electric Vehicles and Wind Power Generation Sources

Sequential flipping: the donor-acceptor exchange mechanism in water trimers.

The donor-acceptor exchange (DAE) is a significant hydrogen bond network rearrangement (HBNR) mechanism because it can lead to the change of the hydrogen bond direction. In this work, we report a new DAE mechanism found in water trimers that is realized by sequential flipping (SF) of all molecules rather than the well-known proton transfer (PT) process. Meanwhile, the SF process has a much smaller potential barrier (0.262 eV) than the previously predicted collective rotation process (about 1.7 eV), implying that the SF process is the main flipping process that can lead to DAE. Importantly, high-precision ab initio calculations show that SF-DAE can make the water ring to show a clear chiral difference from PT-DAE, which brings the prospect of distinguishing the two confusing processes based on circular dichroism spectra. The reaction rate analysis including quantum tunneling indicates an obvious temperature-dependent competitive relationship between the SF and PT processes; specifically, the SF process dominates above 65 K, while the PT process dominates below 65 K. Therefore, in most cases, the contribution for DAE mainly comes from the flipping process, rather than the PT process as previously thought. Our work enriches the understanding of the DAE mechanism in water trimers and provides a piece of the jigsaw that has been sought for the HBNR mechanism.

Circularity in polymers: addressing performance and sustainability challenges using dynamic covalent chemistries.

The circularity of current and future polymeric materials is a major focus of fundamental and applied research, as undesirable end-of-life outcomes and waste accumulation are global problems that impact our society. The recycling or repurposing of thermoplastics and thermosets is an attractive solution to these issues, yet both options are encumbered by poor property retention upon reuse, along with heterogeneities in common waste streams that limit property optimization. Dynamic covalent chemistry, when applied to polymeric materials, enables the targeted design of reversible bonds that can be tailored to specific reprocessing conditions to help address conventional recycling challenges. In this review, we highlight the key features of several dynamic covalent chemistries that can promote closed-loop recyclability and we discuss recent synthetic progress towards incorporating these chemistries into new polymers and existing commodity plastics. Next, we outline how dynamic covalent bonds and polymer network structure influence thermomechanical properties related to application and recyclability, with a focus on predictive physical models that describe network rearrangement. Finally, we examine the potential economic and environmental impacts of dynamic covalent polymeric materials in closed-loop processing using elements derived from techno-economic analysis and life-cycle assessment, including minimum selling prices and greenhouse gas emissions. Throughout each section, we discuss interdisciplinary obstacles that hinder the widespread adoption of dynamic polymers and present opportunities and new directions toward the realization of circularity in polymeric materials.