REACTIVE & FUNCTIONAL POLYMERS
·
2023
·
IF 5.1
Liwei Lu,Xia Sun,Aohuan Guo,Hancheng Yu,Caili Yu,Zhongqun Zhou,Faai Zhang
Employment of noncovalent bonds as reversible crosslinks have been applied in weldable and self-healing crosslinked polymer networks but result in limited mechanical properties . Herein, a robust, tunable, and fast healable poly(urethane-urea)-GMA (PG) elastomer with a combination of multiple hydrogen bonds and dynamic covalent urea bonds was designed via a photo-induced copolymerization . The resultant PG60 exhibited a tensile strength of 12.3 MPa, an elongation at break of 229%, a toughness of 16.08 MJ m −3 , and a self-healing efficiency of 100.0%. By adjusting the content of dynamic crosslinkers, the mechanical strength and self-healability of the resulting elastomers can be optimized. The exceptional properties of the networks, including self-healing capability and remarkable robust mechanical behavior, are attributed to the presence of reversibly noncovalent hydrogen bonds and dynamically covalent urea bonds, which have been confirmed through stress relaxation tests. More importantly, this study not only presents a facile fabrication method for designing mechanically robust and fast self-healing crosslinked elastomers, but also shows great potential in smart humidity sensor .
研究领域:
材料科学
·
智能传感
✓ 已验证
产品关联
DOI
高影响因子
MACROMOLECULAR MATERIALS AND ENGINEERING
·
2020
·Vol. 306
·期 1
·2000527
·
IF 3.853
Zhongqun Zhou,Shenye Chen,Weichen Li,Junjie He,Caili Yu,Faai Zhang
Polymer networks crosslinked by reversible noncovalent crosslinks have been applied in self-healing and recyclable sustainable materials but result in limited mechanical strength. Herein, a crosslinked polymer blend that is based on a urethane–arcylate system with a combination of reversibly noncovalent intrachain and interchain hydrogen bonds and dynamically covalent urea bonds is developed through facile in situ photo-induced copolymerization. An essential step is the introduction of a flexibly dynamic crosslinker bearing robustly hindered urea bonds and urethane–urea structures into the network, which endows the dynamic network with a synergy of mechanical robustness and desirable self-healing ability. The dynamic networks exhibit rapid self-healing at mild conditions (70 °C, 30 min), extreme toughness (≈34.76 MJ m −3 ), high tensile strength (≈7.78 MPa), superior stretchability (≈932%), long-term stability, recyclability, and weldability. More importantly, the mechanical and self-healing properties of the resultant materials can be fine-tuned by adjusting the dynamic crosslinker content. These superior properties are attributed to the dynamic reversibility of hydrogen bonds and urea bonds as monitored by rheological tests. The extremely facile fabrication approach and superior properties of the resulting self-healing polymers can find applications in sustainable smart materials and self-healing conductive sensors.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
Smart Materials and Structures
·
2020
·Vol. 29
·期 11
·115041
·
IF 3.613
Zhongqun Zhou,Yanning Zeng,Caili Yu,Haibo Chen,Faai Zhang
Designing a crosslinked polymer with self-healing, recyclable, and mechanical properties is a significant challenge in the field of self-healing chemistry. Herein, robust, intrinsically self-healing, crosslinked polyureas (C-PUs) are prepared via a facile one-pot photo-induced copolymerization to address the aforementioned limitation. The key strategy involves the introduction of a synthetic monomer with reversible urea bonds into the polymer network as a versatile dynamic crosslinker. The resultant C-PUs are a class of resource-saving materials with a combination of excellent intrinsic self-healing capability with outstanding mechanical robustness. Notably, the properties of the materials can be easily tuned by simply adjusting the dynamic crosslinker content. In addition, an environmentally friendly polymer reprocessing is achieved and the potential of the materials in the smart anticorrosion application is investigated. These desirable properties are attributed to the underlying topological network rearrangement enabled by the dynamic urea bond exchange reaction, which is confirmed by stress relaxation tests. Therefore, the resulting self-healing C-PUs can serve as models to extend the scope of applications in smart protective materials or ocean engineering.
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
POLYMER DEGRADATION AND STABILITY
·
2020
·
IF 4.032
Hui Zhang,Xiaojing Cui,Hongliang Wang,Yuqi Wang,Yuhua Zhao,Hui Ma,Lin Chai,Yingxiong Wang,Xianglin Hou,Tiansheng Deng
Deep eutectic solvents (DESs) have attracted broad attention due to their low cost and toxicity, easy preparation, good biological compatibility and similar characteristics to those of ionic liquids. In this study, a DES system composed of choline chloride and urea has been applied for the controllable degradation of polyurethane (PU). By the combination of Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance spectroscopy (NMR) and matrix-assisted laser analytical ionization time-of-flight mass spectrometer (MALDI-TOF-MS), the selective cleavage of carbamate and urea bonds with little damage on carbonate bonds was achieved in the DES system by the regulation of reaction conditions, which favored the recovery of both valuable polycarbonate diol (PCDL) and 3,3′-Dimethyl-[1,1′-biphenyl]-4,4′-Diamine (o-toluidine). The degradation rate of PU and the yield of PCDL reached 100% and 57.4% respectively under mild conditions (1 atm, 170 °C, 8 h). A possible degradation mechanism was proposed based on the experimental results, in which the synergistic effect of choline chloride and urea activated largely the carbamate bond and thus led to a controlled degradation of PU.
研究领域:
材料科学
·
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL CROPS AND PRODUCTS
·
2022
·
IF 6.449
Dong-Mei Xie,Xiao-Li Zhao,Yi-Dong Li,Yunxuan Weng,Jian-Bing Zeng
The development of castor oil-based polyurethanes has been restricted significantly because they have poor mechanical properties and cannot be reprocessed or recycled owing to their soft backbone combined with irreversible crosslinked structures. Herein, we synthesized novel castor oil derived dynamic polymer networks (DPNs) based on reversible piperazine-urea bonds, which were obtained by reacting isocyanate group with inexpensive anhydrous piperazine . The six-membered heterocyclic bifunctional piperazine acted as structural modifier to adjust the network stiffness and crosslink density and thus the mechanical properties of the DPNs. Soft, tough and even hard DPNs could be obtained easily by changing the feed content of piperazine. The reversible piperazine-urea bonds imparted DPNs with excellent malleability, reprocessability, and recyclability. In addition, the DPNs showed excellent solvent resistance, thermal stability, and durability. This study provides an important guidance for the synthesis of vegetable oil derived polymer networks that integrate tunable mechanical properties, reprocessability, and recyclability.
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
REACTIVE & FUNCTIONAL POLYMERS
·
2024
·
IF 4.5
Jingjing Qin,Jiaming Liu,Dingsong Wang,Wanyan Li,Youwei Zhu,Liyan Liang,Chaolong Yang
In order to address the relative brittleness and non-recyclability defects of traditional cross-linked epoxy resins, a novel self-healing and reprocessable epoxy resin based on dynamic piperazine-hindered urea bonds (PA-HUBs) was synthesized. Piperazine is a cheap cyclic diamine, which can regulate the skeleton stiffness of epoxy network and control the mechanical properties of epoxy materials. The tensile strength of cured epoxy resin reaches 103 MPa. In addition, the piperazine monomer contains two methyl substituents and an asymmetric aliphatic ring structure, which provides sufficient chain mobility to activate dynamic exchange reactions, and imparts highly dynamic properties to the conventional urea bond, allowing the urea bonds to possess both stability and dynamic properties. Consequently, the synthesized epoxy resin exhibits not only the excellent mechanical performance but also the remarkable self-healing, reprocessable, shape memory and shape reconfiguration capabilities. The epoxy samples with scratches can basically achieve self-healing within 10 min, and the mechanical properties recovery rate of welded splines is as high as 80 %. Furthermore, we also regulated the content of dynamic PA-HUBs and the cross-linking density of the resin network to examine their impact on the dynamic properties and mechanical performance. Further analysis showed that the higher dynamic bond content and lower cross-linking density increase the free volume of dynamic bond exchange and the stress relaxation rate, which further improves the exchange efficiency of dynamic bonds and endows the resin with better self-healing ability. This kind of piperazine-hindered urea bond, which is dynamically adjustable and has both mechanical stability and dynamic properties, introduces a novel approach for solving the balance problem between the mechanical and dynamic performance of thermosets and preparing dynamic polymer materials with excellent performance.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
Smart Materials and Structures
·
2023
·Vol. 32
·期 6
·065021
·
IF 4.1
Liwei Lu,Caili Yu,Zhongqun Zhou,Faai Zhang
In recent years, the use of renewable biomass resources to prepare self-healing polymers has become a hot research topic because of the shortage of fossil resources. Herein, a novel type of rosin-based cross-linked polymer (PR) with dynamic urea and multiple hydrogen bonds is fabricated by copolymerizing a rosin ester with a dynamic crosslinking agent poly(urethane-urea) through a simple UV-initiated reaction. Owing to its robustly dynamic bonds, the resulting PR has both good mechanical properties and ideal self-healing ability. Specifically, the PR with 25.4% biomass rosin reaches a tensile strength of up to 4.1 MPa, an elongation at break of 112%, and stress self-healing efficiency of 91.3% at 80 °C for 24 h. Remarkably, the PR with a glass transition temperature above room temperature exhibits good shape memory behavior and excellent weldability (afford 2500 g after healing at 80 °C for 5 h). Finally, by surface platinum spraying and pre-stretching treatment, strain sensors based on microcracking mechanisms are realized.
研究领域:
材料科学
·
可再生资源化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Shuqiang Peng,Naveen Thirunavukkarasu,Jie Chen,Xinxin Zheng,Chuanzhou Long,Xianmei Huang,Zixiang Weng,Longhui Zheng,Haopeng Wang,Xiangfang Peng,Lixin Wu
As flexible sensors are soft and prone to damage in practical applications, stretchable conductors with self-healing capacity can extend their service life. However, existing vat photopolymerization (VP) 3D-printed self-healing elastomers generally have a tensile strength of less than 1 MPa, which limits the load-bearing capacity and application range of the flexible sensors. Herein, a photocurable oligomer comprising dynamic hindered urea bonds (HUBs) was synthesized to prepare self-healing elastomers. By using a surface-functionalized spherical nano-silica (Nano-SiO 2 ) for reinforcement modification, the tensile strength and elongation at break of the 3D-printed elastomer were enhanced by 73.7% and 111.3%, respectively, without compromising the transparency and photopolymerization rate. The fractured elastomer exhibited a high tensile strength of 5.44 MPa and a stretchability of 372% after self-healing. Subsequently, a stretchable ionic conductive elastomer (SICE) with high transparency and self-healing properties was developed by incorporating ionic liquids into the 3D-printed elastomer. The high resolution of VP-based 3D printing allowed the construction of pyramid-Kelvin lattice microstructures in the pressure sensor, which enhanced the pressure sensitivity of the sensor several times compared to the pyramid structure. In addition, combining Voronoi tessellation and kirigami art to fabricate tailored wearable sensors with smart structures, broadens the application range and improves the wearing comfort of the sensors.
研究领域:
材料科学
·
生物医学工程
·
3D 打印技术
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2022
·
IF 10.383
Xingyuan Lu,Lun Zhang,Jihai Zhang,Chao Wang,Aimin Zhang
With the advancement of material science and electronic technology, wearable devices have been integrated into daily lives, no longer just a stirring idea in science fiction. In the future, robust multifunctionalized wearable devices with low cost and long-term service life are urgently required. However, preparing multifunctional wearable devices robust enough to resist harsh conditions using a commercially available raw material through a simple process still remains challenging. In this work, reprocessable polyurea (HUBTPU) with a hard segment of hindered urea bonds (HUBs) and a soft segment of polyether is synthesized via a facile one-pot method. The robust dual functional wearable devices were obtained by simply spray-coating silver nanowires (AgNWs) on HUBTPU elastomer substrates. Due to the dynamic combination and decomposition of the HUBs and hydrogen bonds at 130 °C, the robust elastomer demonstrates favorable adhesion to various substrates. Especially, the partially embedded AgNW structure is also achieved by using ethanol as a spray solvent. The adhesion of HUBTPU substrates and embedded structure leads to stronger interfacial adhesion and stability compared to non-adhesive substrates. The as-obtained HUBTPU electrodes are able to be heated to 115 °C by applying a low voltage and sensing the strain deformation caused by human movement, which means that the electrodes are endowed with both electrical heating capability and strain sensing functionality. Therefore, this strategy reveals a potential way to prepare multifunctional wearable devices using other conductive particles and adhesive functional polymer substrates.
研究领域:
材料科学
·
电子技术
·
可穿戴技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ADVANCED MATERIALS
·
2023
·Vol. 35
·期 20
·2211731
·
IF 29.4
Yu Wang,Jinbo Li,Lingyu Sun,Hanxu Chen,Fangfu Ye,Yuanjin Zhao,Luoran Shang
Liquid metal (LM)-based elastomers have a demonstrated value in flexible electronics. Attempts in this area include the development of multifunctional LM-based elastomers with controllable morphology, superior mechanical performances, and great stability. Herein, inspired by the working principle of electric toothbrushes, a revolving microfluidic system is presented for the generation of LM droplets and construction of desired elastomers. The system involves revolving modules assembled by a needles array and 3D microfluidic channels. LM droplets can be generated with controllable size in a high-throughput manner due to the revolving motion-derived drag force. It is demonstrated that by employing a poly(dimethylsiloxane) (PDMS) matrix as the collection phase, the generated LM droplets can act as conductive fillers for the construction of flexible electronics directly. The resultant LM droplets-based elastomers exhibit high mechanical strength, stable electrical performance, as well as superior self-healing property benefiting from the dynamic exchangeable urea bond of the polymer matrix. Notably, due to the flexible programmable feature of the LM droplets embedded within the elastomers, various patterned LM droplets-based elastomers can be easily achieved. These results indicate that the proposed microfluidic LM droplets-based elastomers have a great potential for promoting the development of flexible electronics.
研究领域:
材料科学
·
微流控技术
·
柔性电子
·
高分子科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）