Journal of Materials Chemistry A
·
2025
·
IF 9.5
Lin Wang,Manman Jia,Hui Jiao,Shukang Ti,Dongmei Yue
Nitrile Butadiene Rubber (NBR) is widely used in aerospace, petroleum exploration, auto parts, and other fields because of its excellent performance. Nevertheless, NBR usually needs to be crosslinked with sulfur or peroxide, which restricts the tensile performance and recyclability of NBR. Herein, a novel strategy was developed to address these issues by introducing dynamic urea bonds into the main chain using a simple, catalyst-free one-pot method. The presence of urea bonds not only provides a large number of hydrogen bonding sites between the molecular chains but also exhibits the remarkable microphase separation properties of thermoplastic elastomers. This approach endows NBR with enhanced dynamic characteristics and significant recyclability. As a result, the as-synthesized multifunctional NBR elastomer (I–A0.5–P0.5) exhibits excellent tensile strength (19.9 MPa), toughness (93.7 MJ m−3), low glass transition temperature (−52 °C), and low compression cold resistance coefficient (0.15 at −55 °C), which are comparable to those of conventionally covalently crosslinked NBR. Importantly, the elastomer can retain its mechanical robustness, chemical structure, and thermal stability after multiple rounds of recycling (after five times of recycling, with a recovery of more than 81%). To broaden the application of NBR products, I–A0.5–P0.5 was crosslinked with sulfur, and its performance was compared with NBR vulcanizates of different acrylonitrile contents. It shows excellent oil resistance and low temperature resistance. Surprisingly, it can also possess the ability to be reprocessed multiple times. This new multifunctional thermoplastic NBR elastomer is of great significance in solving the problem of difficult recycling of traditional NBR and is expected to replace traditional covalently cross-linked NBR.
研究领域:
材料科学
·
化学工程
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DOI
高影响因子
PROGRESS IN ORGANIC COATINGS
·
2021
·
IF 5.161
Zhongqun Zhou,Shenye Chen,Xinmeng Xu,Yang Chen,Lanpin Xu,Yanning Zeng,Faai Zhang
Designing a crosslinked polymer with autonomous self-healing at room temperature (RT) remains an arduous challenge because the topological network reconstructions are governed by crosslinking. Herein, a flexible strategy is described to develop intrinsically dynamic crosslinked elastomers with RT self-healing via a photo-initiated copolymerization to address these issues. The key is to incorporate a urea–urethane structure with dynamic urea bond into the polymer network as a flexible crosslinking unit. This strategy endows the crosslinked elastomer with superior properties, including autonomously rapid self-healing at RT, extreme stretchability of up to 1726%, high toughness (∼24.45 MJ m –3 ), extended stability, and recyclability. Upon damaged, the resultant elastomers instantly self-heal at RT and completely self-heal within 10 min without the assistance of external triggers. These amazing properties of the dynamic elastomer are attributed to the synergistic effect of the robustly dynamic urea bonds and inter- and intrachain hydrogen bond interactions. Notably, the self-healing and mechanical properties of the network can be optimized by tuning the dynamic crosslinker content. Dynamic reversibility occurs at RT evidenced by rheological tests. The facile fabrication method and multifunctional properties of the self-healable and stretchable crosslinked elastomer demonstrate that it shows great potential in smart protective coating and wearable electronics industry.
研究领域:
材料科学
·
高分子化学
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DOI
高影响因子
MACROMOLECULES
·
2024
·
IF 5.1
Dongfei Zhang,Ao Wang,Wenkai Liu,Ao Zhen,Jiehua Li,Feng Luo,Xianglong Han,Zhen Li,Hong Tan
The reported dynamic covalent bonds (DCBs) exhibit certain drawbacks, including sluggish reaction rates and high dissociation temperatures, which impede the reusability of DCBs cross-linked polymers. Herein, we develop a kind of imidazole-urea bond (IUBs) through the rapid self-catalytic reaction between imidazole and isocyanate without additional catalysts. The IUBs are found to be highly reversible via a thermally dissociative mechanism while also demonstrating an irreversible exchange with amines. Then, histamine (1H-imidazole-4-ethanamine) is first employed as a chain extender to construct IUBs in the synthesis of novel imidazole-based cross-linked polyurethane-ureas (IMCPU). The IMCPU can undergo multiple recyclings of melt processing and be aminolyzed even at room temperature. Given the wide availability of the commodity histamine, IMCPU exhibits great potential for broad applications in the fields of dynamic materials.
研究领域:
材料科学
·
化学
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产品关联
DOI
高影响因子
PROGRESS IN ORGANIC COATINGS
·
2023
·
IF 6.6
Biru Shi,Yinglu Sun,Xinxin Tian,Jiahui Zhong,Zhenyu Zhang,Xiangdong Liu,Dekun Sheng,Yuming Yang,Wenhua Zhang
Adhesives are widely used to bond various materials and surfaces, hot melt adhesives (HMAs) have conquered almost every industry area due to their solvent-free volatilization and ease of use. However, preparing reusable HMAs with high shear strength is still extremely challenging. Here, we show a simple way to prepare a reusable HMA, OPU (oxime-based polyurethane), with high lap shear strength based on oxime-urethane bonds. Cu(II) ions were introduced to further enhance the bulk strength to form ligand bonds. The relationship between the ligand bond content and the material properties was also investigated. Increasing ligand bond content limited the degree of crystallinity and shear strength. And the breaking stress and toughness of the coordinated material were significantly increased. The initial shear strengths of OPU for 304 stainless steel (after this referred to as “steel”) and aluminum reached 12.6 MPa and 9.3 MPa, respectively, which is the highest shear strength available for oxime-urethane-based polyurethane HMAs. After 10 repetitions, the OPU still retains its high shear performance. By analyzing the relationship between shear strength and the amount of Cu(II), it is found that the shear strength is strongly related to chain mobility and Young's modulus . This work demonstrates a useful way of synthesizing reusable HMAs with high lap shear strength.
研究领域:
材料科学
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化学工程
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DOI
高影响因子
Journal of Materials Chemistry C
·
2021
·Vol. 9
·期 27
·8579-8588
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IF 7.393
Wenjie Sun,Lei Zhang,Shuang Wang,Jiale Mao,Jiaming Luo,Yu Chen,Yonghong Cheng
A silicone-containing dynamic hindered urea bond is demonstrated in this study for application in flexible electronics. Generated from isocyanate and piperazine, these dynamic hindered urea bonds endow silicone with high healing and recycling ability under mild conditions, together with an enhancement of more than 50% in tensile strength. By adjusting the piperazine and glycerol amount, the influences of the dynamic bond concentration and crosslinking density were also investigated. It was found that a higher piperazine amount improves the healing ability and recyclability, while increasing the glycerol fraction can enhance the tensile strength and elongation, but deteriorates the healing and recycling. Flexible conductive materials were prepared by filling the developed silicone with graphene. Admirable flexibility, healing ability and a sensitive response to resistance changes were prototyped by a flexible circuit with the light signal.
研究领域:
材料科学
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化学工程
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2024
·
IF 4.9
Rong Huang,Aoshuang Yang,Ziyu Liu,Fangxing Liu,Tian Fang,Fangfang He,Yongsheng Li,Zhuoni Jiang,He Lan,Kai Zhang,Wenbin Yang
Traditional poly(ethylene glycol)-based polyurethane phase change materials (PUPCMs) are difficult to reprocess and non-recyclable because of their permanently cross-linking structure, leading to issues of resource waste. To overcome this problem, this study introduces dynamic bonds in PUPCMs to develop dynamic cross-linking networks. A series of polyurethane phase change materials containing dynamic oxime-urethane bonds (DOU-PUPCMs) are prepared using poly(ethylene glycol) (PEG), dimethylglyoxime (DMG) and hexamethylene diisocyanate (HDI) as raw materials. It has been shown that the obtained DOU-PUPCMs exhibit good heat storage capability and outstanding thermal stability. Importantly, the introduction of oxime-urethane groups provided DOU-PUPCMs with processibility. After multiple reprocessing cycles, the chemical structure and energy storage capacity of the DOU-PUPCMs essentially remain consistent with the original samples. The breaking and restructuring of oxime-urethane bonds and hydrogen bonds in DOU-PUPCMs makes them recyclable. This is not only significant for the development of recyclable and sustainable energy storage materials , but also complements studies such as the application of oxime-urethane bonds to PCMs.
研究领域:
材料科学
·
能源工程
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产品关联
DOI
高影响因子
ACS Applied Polymer Materials
·
2021
·
IF 4.089
Wenjie Sun,Jiaming Luo,Lei Zhang,Yue Chen,Pengxin Li,Yiting Zheng,Yonghong Cheng
Silicone-containing dynamically hindered urea bonds are developed as a smart insulating material for power equipment and electronic devices. In this work, silicones are constructed by isocyanate–piperazine-based dynamic bonds with cross-linking degree adjusted by glycerol. Healing and recycling based on dielectric and insulating properties are mainly emphasized in this study. We find that dynamic bonds not only heal the cut-damaged feature of the silicone but also enable dielectric property recovery. A healing efficiency above 95% and a recycling efficiency above 90% based on insulation performance are achieved. After recycling, cross-linked silicone exhibits only a slight variation in permittivity and tan δ, while linear silicone shows an apparent increase. Insulation performance of materials with different cross-linking agent concentrations is also investigated. A higher cross-linking degree was found to further improve insulation properties but reduces the recycling efficiency. Importantly, the developed silicones exhibit high intrinsic insulation properties, comparable to commercial silicone materials, which are very attractive for electrical applications.
研究领域:
材料科学
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电气工程
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DOI
高影响因子
Nature Communications
·
2025
·Vol. 16
·期 1
·1-11
·
IF 15.7
Gao Haoyu,Huang Xianmei,Arockiyasamy Abilash Rosario,Zhou Xuan,Ding Xiaohong,Zheng Longhui,Liu Yilong,Ye Fuquan,Weng Zixiang,Wu Lixin
Vat photopolymerization 3D printed flexible polymer foams, characterized by their porosity and lightweight nature, are in high demand for applications in thermal insulation, sound absorption, noise reduction, and biomedicine. The vat photopolymerization used UV-curable resin composed of oligomer can provide excellent fabrication accuracy, however the high cross-linking density after curing prevents the green part from expanding and further being processed into foam parts. In this work, a facile additive manufacturing polyurethane foam preparation method that successfully balances fabrication accuracy and expansion ratio is presented. The oligomer containing difunctional dynamic polyurea bonds in the resin system ensures the printing accuracy. Additionally, the dynamic urea bonds disassociate under a heating condition, reducing the cross-linking density and providing free space for expansion. Moreover, heat stimulated chain extension and crosslinking enhance the stretchability of the foams, demonstrating a strain of up to 650% at a density of 0.25 g/cm 3 . This work addresses the challenge associated with fabricating free foaming parts via vat photopolymerization by delivering favourable surface quality and high expansion ratio without compromising mechanical properties.
研究领域:
材料科学
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化学工程
·
生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
POLYMER DEGRADATION AND STABILITY
·
2025
·
IF 7.4
Jingjing Qin,Dingsong Wang,Wanyan Li,Liyan Liang,Chaolong Yang
Compared with a single dynamic covalent network, the introduction of dual dynamic bonds can significantly improve the comprehensive properties of materials. In this study, we introduced dynamic hindered urea bonds and low-bond-energy dynamic disulfide bonds into the epoxy dynamic network and synthesized epoxy polymers based on dual dynamic covalent bonds. Among them, the existence of curing agent containing disulfide bond can improve the rigidity of the crosslinked network and greatly improve the tensile strength of epoxy resin. However, epoxy resin cured exclusively with disulfide-based agents exhibit elevated glass transition temperature, and the exchange reaction of disulfide bond is frozen. It usually takes a very high temperature (above 180 °C) to repair the damage by disulfide bond rearrangement. While the flexible urea bond curing agent can improve the movement ability of the chain segment of epoxy resin from the molecular structure, thus reduce the glass transition temperature, and greatly reduce the processing difficulty of epoxy resin while toughening. The experimental results show that the dual dynamic network demonstrates accelerated stress relaxation behavior at high temperatures, which can be completely relaxed within 1 min at 130 °C, the activation energy is only 58.19 kJ/mol, and the resin scratch can be completely repaired by heating at 130 °C for 5 min. What’s more, the mechanical properties of the dynamic network have been significantly improved due to the existence of disulfide cross-linking network with high strength and high cross-linking density, with the tensile strength reaching 92 MPa and the elongation at break reaching 11.9 %. In addition, in the mixed solution of N, N-dimethylformamide/DL-dithiothreitol (DMF/DTT), the resin can be completely degraded to a transparent solution. The construction of dual dynamic crosslinked networks successfully addresses the long-standing dilemma between dynamic performance and mechanical properties in conventional dynamic bond resins, while simultaneously overcoming the recycling and degradation challenges inherent to thermosetting epoxy resins, endowing epoxy dynamic network with more excellent comprehensive performance. The research results can also provide an effective solution for the waste treatment of epoxy resin/carbon fiber composites and has good application potential.
研究领域:
材料科学
·
高分子化学
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产品关联
DOI
高影响因子
ACS Applied Polymer Materials
·
2024
·
IF 4.4
Fenglong Li,Xiaolin Wang,Jiyang Zuo,Chao Chen,Jing Chen,Jin Zhu,Wu Bin Ying
3D printing has emerged as a highly accurate, highly customizable, and low-cost fabrication method to realize structures with designed geometry. However, the integral printing of complex structures, such as suspended structures, still poses significant challenges in the most commonly used 3D printing technology-fused filament fabrication (FFF). Therefore, designing a self-healing material, segmenting the printing of complex structures, and finally assembling them into a whole by the self-healing capability are expected to resolve this issue. In this research, we successfully synthesized a self-healing polyurethane (LNPU-3) with the introduction of dynamic oxime-urethane bonds. Specifically, we employed polycaprolactone diol as the soft segment, 2,4-pentanedione dioxime as the chain extender, and 4,4′-methylenebis(phenyl isocyanate) as the hard segment. LNPU-3 exhibited outstanding mechanical properties, with a tensile stress of 8.5 MPa and a fracture toughness of 20.1 MJ/m3. Even after cyclic stretching five times at a strain of 30%, the specimen could still recover 95% of its original value. Furthermore, LNPU-3 could be fully self-healed at room temperature (25 °C) within 8 h, with a healing efficiency of 92.9%. Finally, LNPU-3 was successfully printed by using FFF and the self-healing capability of the printed samples was tested. The printing components were then assembled into a complex structure that was difficult to print as a whole. In summary, LNPU-3 is an ideal self-healing 3D printing material, demonstrating significant potential for the application of self-healing materials and the advancement of 3D printing technology.
研究领域:
材料科学
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化学工程
·
3D打印技术
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产品关联
DOI
高影响因子
REACTIVE & FUNCTIONAL POLYMERS
·
2019
·
IF 3.074
Lei Zhang,Haiqing Wang,Zenghui Dai,Zhongxiang Zhao,Feiya Fu,Xiangdong Liu
Dynamic covalent chains that composed of three or five dynamic polyurea bonds are introduced into cross-linked polyurethane to overcome the classical dilemma between healing rate and thermo-mechanical properties. Comparing with dynamic urea bond, the incorporation of the dynamic polyurea chains with multiple leads to significantly improved thermo-mechanical performance and healing rate/efficiency on the network. Remarkably, several folds' increases in tensile and adhesion shear strength as well as 53 °C enhancement in glass transition temperature are achieved without sacrificing the material properties of the polyurethane network. We attribute the improvements to the decomposed polyurea chain segments, which have higher diffusivity and larger quantity than the dynamic urea bond that tied in the control network. This study provides a concept of dynamic covalent chain to address the classical dilemma between healing performances and thermo-mechanical properties among healable thermosets .
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS CHEMISTRY AND PHYSICS
·
2021
·
IF 4.094
Zhongqun Zhou,Yanning Zeng,Caili Yu,Quanyang Li,Faai Zhang
The development of self-healing elastomers with superior physical properties is a challenging task. Herein, we present a design concept for a self-healing, highly stretchable, and robust poly(urethane–urea) elastomer prepared via a thiol-ene click reaction by a facile one-pot in situ photopolymerization method. The objective of the utilized approach is to incorporate weak noncovalent H-bonds, dynamic covalent urea bonds, and products of a thiol-ene click reaction into a polymeric backbone. This study also applies polytetramethylene ether glycol domains as soft segments to facilitate the polymeric chain diffusion and dynamic exchange reaction. Owing to these unique molecular characteristics, the resultant elastomer possesses a uniform structure and versatile properties, such as high stretchability corresponding to a maximum strain of 464%, ultimate tensile strength of 10.9 MPa, self-recoverability, high self-healing efficiency of 99%, high recyclability, and good weldability . Upon rupture, the as-prepared elastomer completely restores its original mechanical properties after heating to 80 °C for 5 h. The dynamic reversibility of the elastomer is evidenced by stress relaxation analysis and rheological testing. In addition, it can be effectively encapsulated and potentially used for fabricating self-healing stretchable conductive devices.
研究领域:
材料科学
·
高分子化学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）