Journal of Materials Chemistry C
·
2019
·Vol. 8
·期 7
·2326-2335
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IF 6.641
Tianyu Yang,Mian Wang,Fei Jia,Xiuyan Ren,Guanghui Gao
Recently, hydrogel-based sensors have been rapidly developed due to their excellent flexibility, stretchability and toughness. However, it is still necessary to develop a hydrogel sensor with shape memory and remolding performance for multi-field applications. Here, a dual physically cross-linked shape memory hydrogel sensor was fabricated via blending poly vinyl alcohol (PVA), cationic chitosan and graphene oxide in water and glycerol. The introduction of cationic chitosan endows the hydrogels with excellent electrical conductivity. Therefore, the hydrogel can be integrated as a strain sensor to repeatedly monitor human motions. Meanwhile, the hydrogel can be used as a thermo-responsive shape memory sensor by virtue of orientation of PVA molecular chains under force and disorientation after heating. Besides, the hydrogel possesses anti-freezing properties with mechanical flexibility at −20 °C. Due to the dual physical cross-linking, the hydrogels can effectively dissipate energy and reconstruct the network; thus, the hydrogels gain excellent strength and remolding properties. In a word, this strategy provides a feasible method to prepare multifunctional shape memory hydrogels applied as wearable strain sensors and shape memory sensors.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
DOI
高影响因子
MACROMOLECULES
·
2018
·
IF 5.914
Sheng Wang,Songqi Ma,Qiong Li,Wangchao Yuan,Binbo Wang,Jin Zhu
Conventional thermosets are built by nonrenewable fossil resources and are arduous to be reprocessed, recycled, and reshaped due to their permanent covalent cross-linking, and their flammability makes them unsafe during use. Here, for the first time, we synthesized a novel Schiff base precursor from abundant and renewable lignin derivative vanillin and produced malleable thermosets (Schiff base covalent adaptable networks (CANs)) combining high performance, super-rapid reprocessability, excellent monomer recovery, and arbitrary permanent shape changeability as well as outstanding fire resistance. The Schiff base CANs exhibited high glass transition temperatures of ∼178 °C, tensile strength of ∼69 MPa, tensile modulus of ∼1925 MPa, excellent flame retardancy with UL-94 V0 rating and V1 rating, and high LOI of ∼30%. Meanwhile, three Schiff base CANs showed high malleability with the activation energy of the bond exchange of 49–81 kJ mol–1 and could be reprocessed in 2–10 min at 180 °C. These Schiff base CANs provide a prime example to foster the development of advanced thermosetting materials from renewable bioresources.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
Materials Today Communications
·
2019
·
IF 1.859
Hui Liu,Wei Zhao,Guanghui Gao,Xiuyan Ren
Herein, a novel double network polyvinyl alcohol/gelatin/glycerol (PVA/GEL/GL) organohydrogel is reported and fabricated. The existence of GEL improves the high mechanical strength based on the strong hydrogen bonds from PVA and GL, endowing the organohydrogels with excellent flexibility and biocompatibility. Especially, PVA/GEL/GL organohydrogels can maintain excellent mechanical flexibility at −25 °C, and possess remarkable non-drying even at 85 °C. It also exhibits good mildewproof property after 15 days. Meanwhile, remoldability endows organohydrogels to be recycled and reused, even as substitute materials for soil to cultivate plants. Thus, PVA/GEL/GL organohydrogels as a biological material have great potential great potential in fields of biomedicine, and even industry and agriculture.
研究领域:
生物医学
·
材料科学
·
农业
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2024
·
IF 2.7
Fansen Meng,Yiyin Yang,Kaiwen Shen,Donglin Tang
In this study, flame retarded polyurethane vitrimers, namely vitrimeric poly(isocyanurate urethane)s (VPICUs), were synthesized successfully by melting polycondensation simply from tris(2-hydroxyethyl)isocyanurate and dicarbamates. By increasing the methylene number in dicarbamates from 4 to 10, the VPICUs exhibit superior mechanical performance with elongation at break increases from 20% to 350% while the tensile strength decreases from 80 to 32 MPa, and the toughness can be significantly enhanced from 9 to 90 J/cm 3 . With a mass fraction of isocyanurate ring at 26.6%, for VPICU10-2.5/2, the flame retardancy is found to be the most excellent, with a UL-94 rating at V-0 and a LOI value at 25.9%. VPICU10 samples exhibit substantial relaxation behavior at higher temperature, and the network rearrangement activated by transesterification and transurethanization reactions offers the reprocessability without losing the properties. This work provides new insights into the construction of sustainable and high-performance flame retarded polymer materials.
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
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2020
·
IF 3.573
Danyi Li,Li Yuan,Guozheng Liang,Aijuan Gu
The rapid development of new-generation flexible touch display panels puts forward more requirements on the overlays, not only including colorlessness and transparency but also having self-healing and remolding abilities as well as high dielectric constant. Herein, new self-healable and remoldable polyurethane films (PULEx) with high dielectric constant have been developed through building of reversible cross-linked networks with special synergistic effect between lithium salt and ionic liquid. The integrated performance of PULEx was systematically investigated. Results show that as the loadings of lithium salt and ionic salt increase, films show increased dielectric constant and self-healing ability. The film with suitable composition (PULE7.5) has the best comprehensive performance; its dielectric constants (104–106 Hz) range from 9.6 to 6.1, which are comparable to those of glass (commonly used overlay for rigid capacitive touchscreen panels). The construction of reversible covalent cross-linking endows PULE7.5 with good mechanical strength, high self-healing efficiency after complete fracture (92.7%), and high recovery of mechanical properties after remolding (91.8%). In addition, the colorless PULE7.5 has high transparency (90.7% transmittance at 550 nm) and can freely convert among three shapes of bending, scrolling, and S-shape, showing great prospects in fabricating flexible display devices. The mechanism behind these outstanding integrated performances of PULE films is investigated through correlation with structures.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2021
·
IF 8.198
Kuan Liang,Ganggang Zhang,Jingbo Zhao,Ling Shi,Jue Cheng,Junying Zhang
The introduction of dynamic covalent bonds into chemically cross-linked networks is an effective strategy to solve intrinsic problems of inability to be reprocessed or recycled for thermosetting polymers. Imine bonds (also known as Schiff bases) are promising candidates for constructing covalent adaptable networks (CANs) because of their easily triggered exchange reactions. However, it remains a challenge for polyimine vitrimers to improve the creep resistance and thermal stability due to their unstable imine-based networks. In this work, we report a green strategy to prepare a series of partially bio-based, malleable, recyclable, and robust poly(amide–imine) vitrimers by bulk polymerization for the first time. The amide bonds are introduced into polyimine vitrimers for the improvement of mechanical property, thermal stability, and creep resistance. A series of H2N-terminated prepolymers with tunable structures were first synthesized, which combined the amide and imine groups together. Then, a bio-based trimethyl citrate was selected as the curing agent to react with H2N-terminated prepolymers for the construction of CANs with amide bonds as cross-linking points. The imine groups accompanied by a dynamic exchange nature endowed the poly(amide–imine) vitrimers with reprocessability, self-healing property, and degradability. Meanwhile, the amide groups with inherent intermolecular hydrogen bonding enhanced the mechanical properties, thermal stability, and creep resistance of poly(amide–imine) thermosets.
研究领域:
材料科学
·
绿色化学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2019
·Vol. 7
·期 30
·18039-18049
·
IF 10.733
Qiong Li,Songqi Ma,Sheng Wang,Wangchao Yuan,Xiwei Xu,Binbo Wang,Kaifeng Huang,Jin Zhu
Dynamic covalent networks offer the favorable features of cross-linked polymers as well as the functions of reprocessing, recycling, self-healing, reshaping, and welding; however, it is a challenge to design readily monomer-recovery, highly malleable, catalyst-free, dynamic materials. Here we report the first design of acetal dynamic networks to address this challenge. Acetal dynamic networks were built via the catalyst-free “click” addition of polyol and a commercial divinyl ether without releasing small molecules. Small-molecule model compounds demonstrated thermally-induced acetal exchange without a catalyst. There are two mechanisms for the dynamic exchange of acetal: one is the metathesis of acetal, another is transacetalization. Acetal dynamic covalent networks exhibited excellent malleability and recyclability. They presented rapid stress relaxation at high temperatures. Hot press recovery can be achieved in 10 min at 150 °C. Meanwhile, the starting material was recovered with 92% recovery in 1 h under hot water treatment at 100 °C, and could be recross-linked with a commercial divinyl ether to obtain an acetal network. The acetal networks recovered by the two methods maintained the original structure and performance. An acetal dynamic linkage will open up a new way for the development of catalyst-free dynamic covalent networks and enrich acetal chemistry.
研究领域:
材料科学
·
有机化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Polymer Materials
·
2022
·
IF 4.855
Yun Tan,Yuyuan Zhang,Ziye Ge,Jun Zheng,Sihe Liang,Yinyi Ma,Mei Wen,Jianghua Li,Zhifang Sun,Chuntai Liu,Shimei Xu,Yi Zhang
To balance the comprehensive requirements of toughness, mechanical strength, rapid self-healing, and high conductivity in supramolecular hydrogels toward wearable devices still remain a tough challenge. This paper presents a simple one-step method to construct supramolecular conductive hydrogels (SCHs) through multilevel electrostatic and coordination interactions between amphoteric polymers and metal ions, which are revealed by the density functional theory (DFT) and noncovalent interaction (NCI) analysis. The SCHs integrate stretchability (more than 1500% and 110 kPa), self-healing, remoldability, large strain sensor (0–500%), and long-term monitoring of motion and electrocardiogram (ECG) with decent conductivity (∼2.5 S/m). The self-healing and remolding of SCHs suffer from temperature dependence. Meanwhile, it is worth noting that the remolded SCHs (R-SCHs) retained all of the properties of the original SCHs (O-SCHs), such as conductivity, intelligent sensing, health monitoring, and so on, indicating that the SCHs constructed in physical cross-linking could achieve sustainable recycling in flexible electronics and smart soft materials.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2020
·Vol. 56
·期 4
·3623-3637
·
IF 3.553
Ning Lijian,Yuan Li,Liang Guozheng,Gu Aijuan
It is still a great challenge to endow remoldable triple-shape memory thermosets (Rtri-SMTs) with high glass transition temperature ( T g ) and high mechanical properties. Herein, two Rtri-SMTs with high T g and high tensile properties, coded as BA1 and BA2, were developed through building unique dynamic crosslinked networks based on bismaleimide and novel bisallyl compounds with dynamic ester bonds (AEG1 and AEG2). The T g values of BA1 and BA2 resins are 143 °C and 203 °C, respectively, much higher than those of Rtri-SMTs reported so far (10–110 °C); meanwhile, BA resins exhibit high tensile strengths (BA1: 81 MPa; BA2: 84 MPa) and moduli (BA1: 2165 MPa; BA2: 3233 MPa), which are severally at least about 1.3–1.4 and 3.2–4.7 times of those Rtri-SMTs in the literature, respectively. Besides the superiorly high thermal and tensile properties, both BA resins are able to be remolded and reconfigured through the re-arrangement of crosslinked networks induced by dynamic exchange reaction of ester bonds. The mechanism behind these attractive properties of BA1 and BA2 resins is discussed. Graphical abstract Remoldable triple-shape memory thermosets with high glass transition temperature, high mechanical properties and good reconfigurability were developed.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
高影响因子
POLYMER
·
2020
·
IF 4.231
Xiaohong Liu,Liyan Liang,Maoping Lu,Xuan Song,Hehua Liu,Guoyang Chen
Vitrimers with dynamic imine bonds generally show low mechanical properties and water resistance. Here, we report a bio-based vitrimers with dynamic imine bonds synthesized from vanillin, m -xylylenediamine and DGEBA. Among them, the imine metathesis reaction of the dynamic imine bond makes the bio-based vitrimers have rapid stress relaxation behavior, self-healing, remoldability and weldability . In addition, the materials also exhibited high mechanical properties (79.1 MPa) and excellent water insensitivity. Even after being immersed in water for 15 days, the materials still showed a tensile strength of 70.5 MPa and a Young's modulus of 2.32 GPa at a breaking elongation of 6.67%. Importantly, due to the hydrolysis of dynamic imine bonds, the materials also exhibited degradation and ecofriendly recycling capabilities under mildly acidic conditions. We envision that this vitrimers with simple process, excellent comprehensive properties and ecofriendly recyclability will make it a potential candidate for applications in sustainable structural materials.
研究领域:
材料科学
·
化学工程
·
环境科学
✓ 已验证
DOI
高影响因子
MACROMOLECULES
·
2025
·
IF 5.2
Yanlin Liu,Zhen Yu,Yajin Fang,Jinping Ni,Junping Zhang,Zhaobin Tang
Although the development of covalent adaptive networks has opened up the possibility of recycling thermosets, the relentless pursuit of such materials must still reconcile the contradiction between comprehensive performance, particularly the contradiction between ultrahigh mechanical strength and malleability or recyclability. To address this issue, a molecular design strategy utilizing synergistic steric and electronic effects in the cyanoguanidine urea (CGUA) network was developed in this work. The dipole–dipole interaction enhances the cohesive energy density and mechanical enhancement, whereas tailored steric hindrance modulates the dynamic bond activation barrier. This yields CGUA networks exhibiting unprecedented mechanical properties, including as tensile strength of up to 150.6 MPa, modulus exceeding 1821 MPa, and toughness surpassing 2996 J m–2, while retaining malleability at 160 and 180 °C. By varying the steric and electronic properties of substituents within the guanidine urea structure, tunable control over polymerization, network dynamics, and mechanical properties can be achieved. This work provides a novel strategy to decouple mechanical robustness from dynamic functionality in recyclable polymers.
研究领域:
高分子化学
·
材料科学
·
物理化学
·
可持续材料
·
功能高分子
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL CROPS AND PRODUCTS
·
2025
·
IF 6.2
Huanbo Wang,Wanting Wang,Jiaxi Kuang,Hongfen Li,Suyong Huang,Lianpeng Zhang,Xijuan Chai,Kaimeng Xu,Linkun Xie,Tian Liu
Preparation of composites that can fully utilize each component's strengths is challenging, especially in the realm of the plant biomass/polymer composites. Here, wood powders with static microstructured and nanostructured networks were combined with a dynamic polyurethane containing dynamic networks to fabricate integral static-dynamic hybrid networks (SDNs) connected through covalent and noncovalent bonds. Hot press-induced wood powder orientation and compression in the SDNs increase the contact area between the wood powder particles and the frictional force between the microfibrils of the wood powder cell walls. These chemical and physical interactions contribute to the high interfacial adhesion in the SDNs, enabling the wood powders and the dynamic polyurethane to achieve their full performance. Thus, the SDNs exhibit high mechanical properties and good thermostability, with tensile strength and flexural strength of 55.37 ± 4.49 MPa and 88.22 ± 3.67 MPa for the SDNs with a wood powder content of 70 wt%. The SDNs (with wood powder contents of 50, 60, and 80 wt%) failed to fully utilize the strength of both the dynamic polyurethane and the wood powder, resulting in lower tensile strengths. Additionally, benefiting from the reversible networks of dynamic polyurethane, the SDNs demonstrate satisfactory reprocessability, with a mechanical properties recovery ratio higher than 70 % even after being reprocessed three times, and they have the potential to be used as a carbon storage reservoir when made into products. Furthermore, the simple preparation process of SDNs is scalable and can be adopted to other waste plant biomass.
研究领域:
材料科学
·
高分子科学
·
复合材料
·
生物质利用
·
可持续化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）