High Fracture Strength Research Articles

Enhanced mechanical properties of epoxy composites using cellulose micro‐ and nano‐crystals

AbstractEpoxy polymers are commonly utilized in structural applications due to their high bearing capacity and excellent chemical resistance. However, their inherent brittleness poses a significant challenge for their use in high shock and fracture strength products. To address this shortcoming, fillers can be incorporated into the polymer during preparation. In this study, we aimed to investigate the effect of incorporating cellulose‐based fillers, namely cellulose nanocrystals (CNCs) and microcrystalline cellulose (MCC), on the mechanical properties of epoxy polymer composites. The study evaluated the impact of various factors, including filler concentration, particle size, and moisture content, on the mechanical properties of the composites. The results demonstrated that the incorporation of CNC or MCC powders at concentrations below 5% could enhance the mechanical properties of the resulting epoxy composites without adversely affecting their surface and thermal properties. The maximum tensile strength and fracture toughness of the filler‐based epoxy composites were achieved at 2 and 4 wt% for CNCs and MCC, respectively. CNCs with a smaller particle size distribution were found to be much more effective than MCC in improving the mechanical properties of the epoxy composites. Furthermore, utilizing dried fillers resulted in a higher improvement in tensile strength, which was achieved at lower filler concentrations.

Enhancement of strength-plasticity synergy in a graphene metallic glass composite

Metallic glass (MG) shows great potential for a wide range of functional and structural applications. However, it remains a challenge to enhance the ductility of metallic glasses without compromising their strength during development. A composite of bulk metallic glass/graphene (BMG/C(n)) was prepared using the suction casting method in argon atmosphere, with a nominal composition of (Zr60Ni20Al20)100-x(C(n))x (x = 5,10,15). The results indicate that the graphene well dispersed in the BMG matrix without any other intermetallic compounds present. Mechanical property testing reveals a significant increase in both plasticity and hardness with increasing graphene content, while maintaining high fracture strength of the BMG matrix.

Development and characterization of nano-magnesia-based refractories filled with graphite nanosheets

Thermo-mechanical and mechanical properties of Magnesia-Carbon (MgO–C) refractories are of great importance in industrial furnace applications and are greatly influenced by the amount of carbon in the MgO Matrix. In this research work, the effect of exfoliated graphite nanosheets (EGS) content on mechanical behavior and thermal shock resistance of MgO-based refractories was examined. MgO nanoparticles were synthesized by the co-precipitation method and micro-MgO particles were used as received. EGS was added in both micro and nano-MgO in variable amounts ranging from 0.5 to 2.5 wt % to study its effect on fracture strength and thermal shock resistance. The morphology of synthesized MgO nanoparticles and the fractured surfaces of the resultant composites were analyzed by field emission scanning electron microscopy (FESEM) coupled with energy dispersive x-ray (EDX) spectroscopy, transmission electron microscopy (TEM), X-ray diffraction analysis (XRD), and compression testing. The synthesized nano-MgO and as received micro-MgO particles were found to be of spherical morphology with no impurity elements as observed by FESEM and EDX mapping. XRD analysis did not show any phase change after the sintering of the composites. The FESEM and TEM images of the fractured surfaces of MgO-EGS refractory samples displayed the fine distribution of EGS. EGS were embedded in MgO particles, enhancing the composite-refractory samples' fractured strength. Fracture strength and thermal shock resistance were increased with the increasing amount of EGS in MgO. However, the highest fracture strength and thermal shock resistance values were achieved for nano-MgO with 2.5 wt% EGS. The resulting refractory samples can be used as furnace linings having a lower carbon content and enhanced thermo-mechanical properties.

Two-dimensional multifunctional metal-organic frameworks with large in-plane negative Poisson ratios and photocatalytic water splitting properties.

Auxetic materials with multifunctional properties are highly sought after for application in modern nano-devices. However, the majority of reported inorganic auxetic materials exhibit low negative Poisson's ratios (NPR), poor flexibility, and limited functionality. In this study, we employ density-functional-theory (DFT) first-principles simulations to design a series of two-dimensional (2D) metal-organic frameworks (MOFs) M2C4X4 (M = Cu, Ag, Au; X = O, S, NCN) that display intriguing auxetic behavior, superior flexibility and appropriate photocatalytic water-splitting properties. These M2C4X4 MOFs are assembled from carbon tetragon motifs and exist in both cis- and trans-isomer forms, with the NPR ranging from -0.17 to -0.90. Notably, trans-Cu2C4(NCN)4 exhibits a high NPR of -0.90, while cis-Cu2C4(NCN)4 achieves an NPR of -0.67. Both isomers demonstrate excellent flexibility, characterized by ultra-low Young's modulus and high fracture strengths. Furthermore, their direct band gaps, strong light-harvesting capabilities, and long excited-state lifetimes make them promising candidates for the photocatalytic oxygen evolution reaction in water. These results provide a viable strategy for the design and synthesis of novel optoelectronic multifunctional materials.

Restorative Modalities for Structurally Compromised Teeth with Thin-walled Roots: A Literature Review

AbstractProper restoration and maintenance of endodontically treated teeth with thin-walled roots and immature apices is of a great concern due to the high prevalence of such cases. The aim of this study was to review the efficiency of different materials used for post–core systems in order to restore endodontically treated teeth. A literature review was conducted using electronic databases including PubMed, Scopus, Web of Science, and Google Scholar to find relevant articles. Randomized controlled trials that were related to different post–core techniques for restoring endodontically treated teeth and were in the English language were included from 2000 until 2022. Most articles concluded that cast posts have higher fracture resistance than fiber posts. All articles comparing stainless steel posts with other materials found that it had higher fracture strength. No particular difference between various types of fiber posts was identified, and all can reinforce the immature roots with thin dentinal walls.

2Y-TZP ceramics with high strength and toughness by optimizing the microstructure

Low-yttria doped zirconia polycrystals (Y-TZP) have recently emerged as new fine-grained zirconia ceramics exhibiting a promising combination of high fracture toughness and strength. In this investigation, we optimized the strength and fracture toughness of 2Y-TZP ceramics prepared by gelcasting and pressureless sintering. The 2Y-TZP ceramics with optimized processing reached a mean biaxial strength of 1070MPa, similar to the strength obtained for the standard 3Y-TZP ceramics. However, a higher transformability of tetragonal grains in 2Y-TZP ceramics resulted in a stronger transformation toughening effect compared with 3Y-TZP ceramics. The fracture toughness obtained for 2Y-TZP exceeded that of 3Y-TZP (7.7 vs. 5.2MPa m0.5). The differences in the microstructure and toughening mechanism between 2Y-TZP and 3Y-TZP were described, and the potential benefits of the 2Y-TZP were discussed.

Mechanical properties and thermal shock resistance of anorthite ceramics obtained by slip casting

Anorthite ceramics (CaAl2Si2O8) was obtained by slip casting of water suspension of kaolin (Al2O3·2SiO2·2H2O) and CaCO3 as a source of CaO. A relative density of 87 % of the theoretical density was achieved after a 3-h-long sintering of green samples at 1200 °C. It was found that slip casting allows the fabrication of anorthite with relatively small pores (<8 μm) which was beneficial for achieving a high fracture strength of 129 MPa and good thermal shock resistance. For a quantitative measurement of thermal shock resistance, a critical temperature interval (ΔTc) was determined by a reduction in the mean fracture strength of at least 30 %. The experimentally determined ΔTc of 300 °C was higher than the value calculated by the equation assuming that the thermal stress created during quenching causes the fracture. It was found that the discrepancy between experimental and calculated values of ΔTc could be explained by an introduction of cracks of various sizes by indentation method and careful observation of crack growth initiation after quenching from various temperatures. It is believed that the reason for the discrepancy lies in the different nature of stress that was used in the theoretical calculation and the stress that acts during sample quenching.

High molecular weight bimodal polyethylene elastomers using N,N'-nickel catalysts appended with methoxy and trifluoromethoxy functionality

Polyolefinic materials displaying bimodal molecular weight distributions are of interest since they can potentially provide mechanical toughness from the high molecular weight component without losing processability on account of the low molecular weight component. With this in mind, a series of nickel(II) complexes, [1-[2,6-{(4-MeOC6H4)2CH}2–4-(F3CO)C6H2N]-2-(ArN)C2C10H6]NiBr2 (Ar = 2,4-Me2C6H3Ni1, 2,6-Et2C6H3Ni2, 2,6-iPr2C6H3Ni3, 2,4,6-Me3C6H2, Ni4, 2,6-Et2-4-MeC6H2Ni5, 2,6-Me2C6H3Ni6) have been synthesized and have shown, following treatment with MMAO or Et2AlCl, excellent activity for the polymerization of ethylene (up to 19.87 × 106 g (PE) mol−1 for Ni4/Et2AlCl) generating high molecular weight branched polyethylene. More importantly, the elastomeric material produced using Et2AlCl as activator displays bimodal characteristics as well as low crystallinity and a medium to high branching density. By contrast, the material prepared using MMAO was more unimodal and showed higher crystallinity and lower branching density. Stress–strain and stress–strain recovery tests performed on the bimodal PE’s revealed a range of tensile properties with a sample prepared using Ni5/Et2AlCl combining both high tensile strength and high fracture strength (σ = 20.3 MPa, ε = 892.0 %). Conversely, a PE sample prepared using Ni4/Et2AlCl showed the highest elastic recovery with a stress relaxation (SR) value of 67.6 %. Besides branching analysis, molecular weight determinations and mechanical tests on the polymers, all nickel complexes and precursor 1,2-bis(arylimino)acenaphthenes, have been characterized by a combination of spectroscopic techniques, elemental analysis and in the cases of Ni1(OH2) and Ni4 by single crystal X-ray diffraction. A theory is also proposed to explain the observed bimodality.

Influence of interstitial carbon content on the microstructure, mechanical and electrochemical corrosion properties of CoFeNiMn multi-principal component alloys

In this study, the effects of carbon content on the microstructural evolution as well as compression and electrochemical corrosion properties of CoFeNiMn multi-principal component alloys (MPCAs) were investigated. A series of (Co25Fe25Ni25Mn25)100−xCx (x = 4, 5, 6, 7, 8) alloys were prepared by vacuum arc melting. Increasing carbon content, the structure transits from a single face-centered-cubic (FCC) phase into a mixed structure containing FCC phase and M23C6 carbides. The yield strength and hardness of the (Co25Fe25Ni25Mn25)100−xCx alloys were enhanced by increasing carbon content, which in turn decreases the ductility. The alloys containing eutectic carbides had a good combination of high yield strength (880 MPa), high fracture strength (2773 MPa), and large fracture strain (47%). Electrochemical measurements indicated that carbon content evidently affects the corrosion resistance of (Co25Fe25Ni25Mn25)100−xCx alloys in 3.5 wt% NaCl solution. Their corrosion resistance initially increases and then decreases with increasing carbon content. The increase in M23C6 carbides can accelerate pitting corrosion and degenerate their corrosion resistance. These findings not only provide comprehensive understanding of the carbon-alloyed behavior in FCC-type MPCAs but also show their potential engineering application as high-performance structural materials.

New biocompatible low modulus and high strength β Ti-Fe-Nb-Sn ultrafine eutectic composites

High strength β Ti–Fe–Nb–Sn ultrafine eutectic composites are promising in structural and functional applications exhibiting high fracture strength with large plasticity. The present work aims to develop new biocompatible β Ti–Fe-based ultrafine eutectic composites using biocompatible elements (Ti, Fe, Sn and Nb) and avoiding and/or controlling the formation of metastable ω phase also known as Laves phase. Five new compositions (Ti64Fe22Nb14, Ti66Nb18Fe16, Ti63Fe23Nb8Sn6, Ti60Fe23Nb8Sn9 and Ti44Fe34Nb16Sn6 (at.%) were produced using Cu-mold suction casting and the evolution of phases and microstructure with the cooling rate and their mechanical properties were investigated. In this sense, was observed a decreasing in the melting point by the addition of eutectoid β-stabilizing elements (Fe and Sn), which leads to values down to Tl = 1215 °C. The samples were characterized by X-ray diffraction, differential scanning calorimetry, scanning and transmission electron microscopy, Young's modulus measurements by the ultrasonic method, microhardness and compression tests. Thus, in this paper are shown promising results on new biocompatible metallic alloys of the TiFeNbSn system with high strength and low Young's modulus due to the adequate combination of a microstructure formed by micrometer-sized β-Ti dendrites with ultrafine eutectics between soft β-Ti phase and hard Ti–Fe and Ti3Sn intermetallics, highlighting alloys Ti64Fe22Nb14 and Ti63Fe23Nb8Sn6. Their yield and fracture strength measured by compression and Young's Modulus measured by ultrasound were 1810 MPa, 2160 MPa and 45 GPa for alloy Ti64Fe22Nb14 and 1915 MPa, 2240 MPa and 59 GPa for alloy Ti63Fe23Nb8Sn6 (at.%)

Realization of dual crosslinked network robust, high toughness self-healing polyurethane elastomers for electronics applications

Currently, research into self-healing polyurethane materials has progressed significantly; however, ensuring that the materials exhibit excellent mechanical properties and good healing efficiency is an urgent problem. In this study, a self-healing polyurethane elastomer exhibiting the synergistic enhancement effect of a double-crosslinked network is prepared by introducing a hydrogen-bond functional monomer and the Diels-Alder reaction. Consequently, the resulting elastomer shows a high fracture strength of 72.5 MPa, an elongation at break of 1241.0 %, an ultrahigh toughness of 235.7 MJ/m3, and a fracture energy of 219.4 KJ/m2. Dynamic covalent crosslinking and reversible hydrogen bonding dual networks endow the elastomers with good self-healing properties and multiple repair capabilities, thus allowing them to achieve up to 86 % self-healing efficiency. In addition, we prepare self-healing capacitive electronic devices using a liquid metal blended and compounded with a dual dynamic bonded polymer system, which exhibit stable electrochemical properties, excellent mechanical properties, excellent self-healing properties, and two-component recyclable properties after mechanical training. The self-repairing device can be reused, thus significantly reducing material waste and pollution, and benefits environmental and resource conservation.

An experimental study on ballistic limit: the effect of hole drilling on the mechanical properties of a polymeric composite plate produced by the resin transfer molding method

The high fracture strength and exceptional impact resistance of polymer-based composites are of paramount importance to various industries like aerospace, automotive, and construction. The resin transfer molding (RTM) process is used to produce composite samples of superior quality, minimal porosity, and reduced lamination defects. In the present study, the RTM method was employed to fabricate glass fiber-reinforced composites, aiming to investigate their specific mechanical properties and structural performance. The study initially determined the ballistic limit of the produced samples. Subsequently, experimental investigations were carried out to examine the impact of hole drilling on the tensile strength, flexural strength, and impact resistance of the samples. The results revealed that the produced polymer plate demonstrated a ballistic limit with a pressure of 11 bar and a speed of 104 m/s, leading to ball restriction in the plate. The sample without holes showed the highest fracture force, while samples with three and five holes exhibited reduced fracture forces. Additionally, bending force and impact resistance were lower in samples with multiple holes compared to the sample without holes. The impact resistance of the sample with five holes was the lowest among all configurations. The study revealed that the presence of three holes arranged in a row has a lesser impact on reducing the ultimate tensile force compared to the effect of five holes. Moreover, the bending test results indicated that sample failure occurred on the side under tension, resulting in higher bending forces than tensile forces.

Inferring mechanical properties of the SARS-CoV-2 virus particle with nano-indentation tests and numerical simulations

The pandemic caused by the SARS-CoV-2 virus has claimed more than 6.5 million lives worldwide. This global challenge has led to accelerated development of highly effective vaccines tied to their ability to elicit a sustained immune response. While numerous studies have focused primarily on the spike (S) protein, less is known about the interior of the virus. Here we propose a methodology that combines several experimental and simulation techniques to elucidate the internal structure and mechanical properties of the SARS-CoV-2 virus. The mechanical response of the virus was analyzed by nanoindentation tests using a novel flat indenter and evaluated in comparison to a conventional sharp tip indentation. The elastic properties of the viral membrane were estimated by analytical solutions, molecular dynamics (MD) simulations on a membrane patch and by a 3D Finite Element (FE)-beam model of the virion's spike protein and membrane molecular structure. The FE-based inverse engineering approach provided a reasonable reproduction of the mechanical response of the virus from the sharp tip indentation and was successfully verified against the flat tip indentation results. The elastic modulus of the viral membrane was estimated in the range of 7–20 MPa. MD simulations showed that the presence of proteins significantly reduces the fracture strength of the membrane patch. However, FE simulations revealed an overall high fracture strength of the virus, with a mechanical behavior similar to the highly ductile behavior of engineering metallic materials. The failure mechanics of the membrane during sharp tip indentation includes progressive damage combined with localized collapse of the membrane due to severe bending. Furthermore, the results support the hypothesis of a close association of the long membrane proteins (M) with membrane-bound hexagonally packed ribonucleoproteins (RNPs). Beyond improved understanding of coronavirus structure, the present findings offer a knowledge base for the development of novel prevention and treatment methods that are independent of the immune system.

An analytical model for the high temperature fracture strength of SiC fiber reinforced ceramic matrix composites considering oxidation and residual thermal stresses

An analytical model for the high temperature fracture strength of SiC fiber reinforced ceramic matrix composites considering oxidation and residual thermal stresses

Predicting fatigue damage growth in cement-treated base layer built with construction and demolition waste

Fatigue damages of cement-treated construction and demolition waste (CDW) aggregate base materials were predicted using a nonlinear elastic-damage model coupled with a finite element (FE) program. CDW with two different gradations (BC1 and BC2) and one control cement-treated base material using quarried aggregate (N1) were tested. Three-point bending strength and fatigue tests were conducted to obtain the fracture property of the three base materials and inputs of the proposed nonlinear elastic-damage model. Pavement structures with the three base layers were modelled by FE simulations, to evaluate the mechanical and cracking performance under three different vehicle load levels of 700 kPa, 840 kPa and 1050 kPa, respectively. The result of experiments shows that the BC1 with a skeleton-dense gradation has the highest fracture strength, which was followed by the N1, and is much higher than the BC2. In the FE simulations, the proposed nonlinear elastic-damage model can well reflect the damage evolution and modulus distribution of cement-treated base layers under vehicle loading. With the accumulation of vehicle loading cycles, the damage of base layers increases, and pavement structure with the BC2 base layer shows the fastest damage evolution. Besides, the stress-dependent modulus shows a non-uniform distribution in the base layers, presenting very high values at the surface and bottom of the base layer due to the high compressive stress and tensile stresses.

Analysis of implant-supported cantilever fixed partial denture: An in vitro comparative study on vertical misfit, stress distribution, and cantilever fracture strength.

To evaluate the vertical misfit, stress distribution around dental implants, and cantilever fracture strength of 3-unit implant-supported cantilever fixed partial dentures (FPDs) using frameworks made from different materials and manufacturing techniques. Forty FPDs were fabricated and divided into 5 groups (n = 8) based on the framework material used: LAS Co-Cr (Conventional casting-laser welding); TIG Co-Cr (Conventional casting -TIG welding); OP Co-Cr (Conventional casting-one-piece); CAD Co-Cr (CAD-CAM); and CAD Zr (CAD-CAM ZrO2). The vertical misfit was evaluated before porcelain application (T1) and before (T2), and after thermomechanical cycling (T3) by stereomicroscopy. Cantilever fracture strength was tested with a 50 kN (5000 kgf) load cell at a crosshead speed of 0.5mm/min. Qualitative and quantitative photoelastic analysis was performed to evaluate stress distribution at seven specific points in five FPDs (n = 1/group) subjected to occlusal loading. Only the molar showed interaction among the three factors (G × S × T; F(20.932) = 1.630; p = 0.044). Thermomechanical cycling (T2 vs. T3) had a significant effect on intra-group vertical misfit in molar, especially in LAS Co-Cr (Δ = 5.87; p = 0.018) and OP Co-Cr (Δ = 5.39; p = 0.007), with no significant effect in premolar (p > 0.05). Ceramic application combined with thermomechanical cycling (T1 vs. T3) caused a significant intra-group increase in vertical misfit in all groups, both in the molar and premolar (p < 0.05). OP Co-Cr was associated with greater vertical misfit and stress concentration. Frameworks manufactured by the CAD-CAM system exhibited lower vertical misfit and better stress distribution. FPDs with metal frameworks (>410.83 ± 72.26 N) showed significantly higher fracture strength (p < 0.05) than zirconia (277.47 ± 39.10 N), and the first signs of ceramic veneering fracture were observed around 900 N. FPDs with frameworks manufactured using a CAD-CAM system appear to be associated with lower vertical misfit and better stress distribution, although the section of the frameworks followed by welding may be a viable alternative. In addition, metal frameworks exhibit high fracture strength.

Transient Translational–Rotational Motion of an Ocean Current Converter Mooring System with Initial Conditions

Systems of ocean current power generation are generally moored deep in the seabed. The mooring system is like ropes. The ropes are very long and can provide tension but not compression, and their dynamic displacement is large and unstable, which is different from traditional structures. To generate high-efficiency ocean current power generation, it is necessary to design a stable mooring system. Maintaining the stability and small dynamic displacement of the ocean current invertor is significantly helpful for the high efficiency of the invertor. In addition, the stability of the mooring system and a small dynamic tension, high safety factor, and long life of the mooring ropes are essential. In this study, we investigate the transient behavior of a mooring system composed of an inverter platform, pontoon, and ropes under initial conditions. An analytical method is proposed. The transient translational and rotational displacements are composed of 36 independent normalized fundamental solutions. The composition depends on the initial conditions. Each fundamental solution is derived by using the Frobenius method. This study proposes the replacement of the traditional single-rope mode with the double-rope parallel mode, which can maintain a high fracture strength and low effective spring constant in the rope. It is verified that this design can decrease instantaneous tension and increase the safety factor of the rope. Additionally, high hydrodynamic damping coefficients can significantly increase the stability of the mooring system.

“Bungee” ionic gel fiber:strength, strain, and multifunctional properties

To adapt to rapid economic and technical development, multifunctional fibers are an active area of research. However, most multifunctional fiber materials exhibit low strength, stretching ability, and elastic recovery. To improve the mechanical properties of multifunctional fibers, an ionic gel fiber was synthesized in this work with high strength, and stretching ability- by random ultraviolet (UV) copolymerization between methacrylic acid and N-isopropylacrylamide in 1-ethyl-3-methylimidazolium ethyl sulfate. The copolymerized ionic gel fibers exhibit high fracture strength and high elastic recovery, they also exhibit anti-freezing capacity, high-temperature resistance, and self-healing. This UV copolymerization method can be applied to other monomers, offering a means of preparing multifunctional fibers.

Mono-dispersion decorated ultra-long single-walled carbon nanotube/aramid nanofiber for high-strength electromagnetic interference shielding film with Joule heating properties

High-strength, flexible, and multifunctional characteristics are highly desirable for electromagnetic interference (EMI) shielding materials to meet lightweight applications in the electric industry. Herein, we report a sustainable bioinspired double-network structural material connected by a hydrogen-bonded interface, that enables the creation of hybrid dual-networks benefiting from the mono-dispersion of aramid nanofibers (ANFs) and single-walled carbon nanotubes (SWCNTs). By directional filtration, the dual networks of the ANF/SWCNT composite films can be constructed into a laminated structure with preferential orientation during the stretching process, resulting in high fracture strength (113.45 MPa) and low breaking strain (<2%). Simultaneously, the as-prepared film delivers an adjustable electrical conductivity (131.9–798.57 S/cm), a remarkable EMI SE (43.01–75.28 dB), and high specific shielding effectiveness (SSE/t) of 1.281 × 104 dB cm2 g−1, which shows outstanding performance among the reported state-of-the-art SWCNT-based materials. More importantly, the films show excellent Joule heating performance with a fast thermal response (<15 s), a low driving voltage (0.5–5 V), and a wide temperature response range (89–445 °C). As such, the multifunctional composite films are considered as promising alternatives to a wide range of lightweight applications in electromagnetic shielding and thermal management.

Ultra-strong, ultra-tough, and transparent polymer composite with excellent dynamic and biodegradable properties enabled by bicontinuous structure

Developing plastics that can integrate mechanical (strength and toughness) and dynamic properties (recyclability, repairability, and biodegradability) is commonly challenging. In this work, inspired by the reinforced concrete structure, an ultra-strong and ultra-tough sustainable polymer composite was constructed through uniformly dispersing cellulose nanofiber in a poly(vinyl alcohol) matrix to form a bicontinuous interwoven network structure based on strong yet dynamic hydrogen bonding crosslink sites. The obtained composite showed an ultra-high toughness, a high tensile fracture strength, good Young's modulus and transparency, as well as excellent dynamic properties including good healing ability, recyclability, and biodegradability. Besides, with excellent gas barrier ability and good water vapor permeability, the composite showed great promise to replace traditional polymers for food packaging and preservation. At last, the mechanism behind the good performances is expected to inspire the design of other healable and green polymers in the future.