JOURNAL OF APPLIED POLYMER SCIENCE
·
2020
·Vol. 137
·期 48
·49575
·
IF 2.52
Zichong Xu,Xiaoyan Wang,He Huang
High-performance thermoplastic polyurethane (TPU) elastomers have long been the objective of numerous studies. In this work, thermoplastic polyurethane–urea (TPUU) elastomers with balanced superior mechanical and thermal properties, in comparison with the rare cases of high-performance TPU/TPUU elastomers with super-high tensile strength, were synthesized by the reaction of polycarbonate diols with excess alicyclic isophorone diisocyanate, followed by the chain extension of alicyclic isophorone diamine. When the content of hard segment was around 47%, the TPUU elastomer had super-high tensile strength of 51.7 MPa, initial elastic modulus of 698 MPa and elongation at break of 480%. The temperature range of this TPUU elastomer's rubbery state was up to 120°C with storage modulus above 200 MPa, and its rubbery flow state reached 200°C where the storage modulus was still as high as 100 MPa. Fourier transform infrared spectroscopy analysis indicated the presence of strongly hydrogen bonded urethane and urea groups in these TPUU elastomers. Atomic force microscopy and differential scanning calorimetry studies demonstrated significant and nearly perfect microphase separation in these TPUU elastomers when the hard segment content was around or below 47%. These noncrystalline TPUU elastomers could be thermally processed or processed in the form of a solution.
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
Nature Communications
·
2023
·Vol. 14
·期 1
·1-10
·
IF 16.6
Wang Xiaoyue,Xu Jing,Zhang Yaoming,Wang Tingmei,Wang Qihua,Li Song,Yang Zenghui,Zhang Xinrui
Self-healing and recyclable polymer materials are being developed through extensive investigations on noncovalent bond interactions. However, they typically exhibit inferior mechanical properties. Therefore, the present study is aimed at synthesizing a polyurethane–urea elastomer with excellent mechanical properties and shape-memory-assisted self-healing behavior. In particular, the introduction of coordination and hydrogen bonds into elastomer leads to the optimal elastomer exhibiting good mechanical properties (strength, 76.37 MPa; elongation at break, 839.10%; toughness, 308.63 MJ m −3 ) owing to the phased energy dissipation mechanism involving various supramolecular interactions. The elastomer also demonstrates shape-memory properties, whereby the shape recovery force that brings damaged surfaces closer and facilitates self-healing. Surprisingly, all specimens exhibite clustering-triggered emission, with cyan fluorescence is observed under ultraviolet light. The strategy reported herein for developing multifunctional materials with good mechanical properties can be leveraged to yield stimulus-responsive polymers and smart seals.
研究领域:
材料科学
·
化学
✓ 已验证
DOI
PubMed
高影响因子
MACROMOLECULES
·
2022
·
IF 6.057
Jialiang Chen,Chichao Li,Huan Jia,Zhihua Shen,Rong Zhao,Tao Su,Bo Xiang,Xiujuan Wang,Danil W. Boukhvalov,Zhenyang Luo,Yanlong Luo
A larger number of studies successfully prepared various polymer materials with excellent self-healing properties, but the study on the underlying self-healing mechanism remains comparably backward and still unclear. In this study, we prepared a self-healing polyurethane-urea (PUU) elastomer based on noncovalent bonds. Then, a coarse-grained model of PUU was successfully constructed using the iteration Boltzmann inversion (IBI) method. Microphase separation and mechanical properties of PUU were reproduced using this model by coarse-grained molecular dynamics (MD) simulation. The three-stage healing mechanism comprised the following: (1) movement of the material to close the gap, (2) interdiffusion of the polymer, and (3) bond exchange. The mechanism was revealed by determining the effects of hard segment content on the microstructure (chain entanglement, interactions of soft and hard segments, chain motility) and healing capacity over healing time. In the initial stage of healing, the polymer chains were disentangled, and the degree of entanglement of the healed samples decreased. A novel experimental strategy confirmed the transition of hydrogen bonds from disorder to order during the healing process. The motility of the cut polymer chains (low molecular weight), especially the cut soft segment, and the disordered hydrogen bonds played a key role in the healing capacity. The increased content of the ordered hydrogen bonds led to the formation of a hard segment network, which was not conducive to healing. Finally, the promoting mechanism of external factors, such as heating and trace amount of solvent, on the healing of PUU was explained. Our work systematically and profoundly reveals the self-healing behavior and mechanism of microphase-separated PUU at the molecular level.
研究领域:
材料科学
·
分子生物学
·
计算化学
✓ 已验证
产品关联
DOI
高影响因子
Materials Today Chemistry
·
2022
·
IF 7.613
S.J. Ding,G.C. Zhu,S. Zhao,L. Zhou,Y.J. Luo
For self-healing polymers, obtaining excellent healing ability and mechanical properties usually need complex chemical structure , external healing conditions, and high manufacturing difficulty. Therefore, self-healing efficiency and rate, mechanical strength , and simple structure design as well as no additional healing conditions of the material are contradictory properties and are difficult to optimize simultaneously. Herein, self-healable thermoplastic poly (urethane urea) elastomers driven by surface energy were fabricated by the introduction of asymmetric alicyclic structures and the healing properties in polymers were optimized by regulating surface energy. The results showed that with the increasing of isophorone diamine contents, the surface energy driving force increased from 36 kPa to 149 kPa, the healing time decreased from 30d to 5d, and healing efficiency, and tensile strength reached 100.9% and 4.04 MPa at room temperature. At the same time, polymers also obtained a high healing efficiency under high-temperature healing conditions. The healing mechanism is that asymmetric alicyclic structures with steric hindrance and ring flip promote the dissociation of hydrogen bonds , provide sufficient chain mobility, decrease the junction density, and improve the surface energy as well as the dissociation and reconstruction of hydrogen bonds. Energetic polymer composites using thermoplastic poly (urethane urea) elastomers as matrix obtained excellent healing properties. This study will offer a novel healing approach for developing advanced self-healing polymer materials.
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
ACS Applied Materials & Interfaces
·
2025
·
IF 8.2
Run-Pan Nie,Hua-Dong Huang,Ding-Xiang Yan,Li-Chuan Jia,Jun Lei,Zhong-Ming Li
The ongoing soft actuation has accentuated the demand for dielectric elastomers (DEs) capable of large deformation to replace the traditional rigid mechanical apparatus. However, the low actuation strain of DEs considerably limits their practical applications. This work developed high-performance polyurethane–urea (PUU) elastomers featuring large actuation strains utilizing an approach of kinetic control over the microphase separation structure during the fabrication process. Additionally, disulfide (DS) bonds were incorporated as dynamic chemical linkages to effectively heal the mechanical damage in the resulting elastomer (PUUDS). Alteration in processing conditions creates notable differences in the rate of phase separation among the multiphase materials. A faster phase separation rate is associated with a reduced degree of microphase separation, increased spacing within hard domains, a higher proportion of disordered hydrogen bonds, and hydrogen bonding index. These changes synergistically improved the electromechanical properties of the PUUDS elastomers, thereby enhancing their actuation performance. The sample processed under the fastest phase separation condition showed the lowest Young’s modulus and a pronounced dielectric response at low frequencies. The electrostriction effect accounts for 89% of the total electromechanical coupling, achieving a significant reduction in the driving voltage during actuation. The maximum actuation strain recorded was 21.6% at an electric field of 45 MV/m. Benefiting from the fully reversible dynamic network, the damaged PUUDS elastomer can be healed and restored to its original elongation at break after 3 h at room temperature. Practical application was demonstrated through the development of a miniature butterfly model constructed from a single-layer PUUDS elastomer, showcasing potential applications in soft robotics. These findings highlight the critical role of kinetic control in optimizing the performance of advanced DEs.
研究领域:
材料科学
·
软体机器人
·
高分子化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MACROMOLECULAR CHEMISTRY AND PHYSICS
·
2020
·Vol. 221
·期 13
·2000145
·
IF 2.335
Bo Zhang,Xiaoxiao Li,Yumeng Tian,Jie Wang,Xiaoli Zhao,Xiaoniu Yang
The use of low molecular weight (LMw) aliphatic diamines for the synthesis of polyurethane-urea elastomers (PUUEs) is an effective method for introducing abundant, strong hydrogen bonds with the aim of improving the thermal and mechanical properties of PUUEs. However, the reaction between isocyanates and LMw aliphatic diamines is too rapid to produce PUUEs. In this study, PUUEs incorporating LMw aliphatic diamines as chain extenders are prepared via the reversible reaction of CO 2 with diamines. The phase separation, thermal properties, and thermomechanical and mechanical properties of polyurethane materials are investigated as the chain extender changed from diol to diamine. Replacing the diol chain extenders with diamine results in the formation of more abundant and stronger hydrogen bonds in PUUEs, which enables the assembly of long range ordered structures and improved microphase separation. The tensile strengths of PUUEs, from 8.4 to 13 MPa, are much higher than their corresponding polyurethanes, owing to the physical crosslinks formed by the more and stronger hydrogen bonds in the PUUEs.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2020
·Vol. 138
·期 8
·49898
·
IF 2.52
Shuxiao Wang,Xiaoyan Wang,He Huang
The efficient surface modification of titanium dioxide (TiO 2 ) particles with different sizes was first carried out with “water only method” (Appl. Surf. Sci. 2018, 447, 664–672) developed in our group using 12-hydroxy stearic acid (12-HSA) as the modifier. The 12-HSA-modified TiO 2 particles with different sizes were then used to explore their effect on the mechanical and thermal properties of a thermoplastic polyurethane urea (TPUU) elastomer with superior mechanical and thermal properties produced newly in our lab using nonsymmetric alicyclic diisocyanate and diamine. Orthogonal experimental results showed that the order of impact of each factor on the modification efficiency of TiO 2 particles was: Temperature > time > modifier content. It was found that, in the nanometer (≤100 nm) range, smaller particles were more helpful to enhance the tensile strength of the TPUU elastomer, while larger ones to increase more significantly the elongation at break. Besides, the TiO 2 /polyurethane urea nanocomposites exhibited much better thermomechanical performance than the pristine TPUU elastomer, and the thermomechanical performance of the nanocomposites increased with decreasing particle size.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2024
·
IF 3.8
Yujia Hao,Guangming Zhu,Ben Li
Developing polymers with high self-healing rates as well as robust mechanical properties remains a significant challenge. Herein, a series of novel self-healing polyurethane-urea (PUU) elastomers with high strength and toughness were prepared using 4,4′-diaminodicyclohexyl methane (HMDA) and N,N′-ditert-butylethylenediamine (DBDA). The HMDA amino groups react with the alicyclic isocyanates to form strong hard segments composed of multiple alicyclic structures and strong urea hydrogen bonds. The strong hard segments play a crucial role in generating strain-induced crystallization (SIC), resulting in improved mechanical properties. The weak hard segments contain dynamic hindered urea bonds and weak hydrogen bonds, which ensures the dynamics of the system and provides the possibility for self-healing. The optimized sample (PUU-2) not only exhibits outstanding tensile strength (49.6 MPa), toughness (385.6 MJ/m3), etc. but also has a healing efficiency of up to 90.5% (at 120 °C for 6 h). This study presents a facile strategy for the design and fabrication of self-healable polyurethane-urea elastomers with high performance.
研究领域:
材料科学
·
高分子化学
·
机械工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2025
·
IF 7.3
Hongliang Ding,Lu Liu,Xiaohua Liu,Hongfei He,Lini Wu,Na Sun,Keqing Zhou,Wei Wang,Chao Ding,Bin Yu
Designing multifunctional polyurethane or polyurea elastomers that are simultaneously strong, recyclable, flame-retardant, and sustainable remains a major challenge in advanced elastomer research. Herein, a phosphorus-containing biobased diol (HMF–DOPO) was synthesized by the reaction between 5-hydroxymethylfurfural (HMF) and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO). Then, the tough, repairable, recyclable, and flame-retardant poly(urethane–urea) (PUA) elastomers cross-linked via reversible Diels–Alder (DA) bonds were developed. The synthesized elastomers exhibited excellent mechanical properties, while PUA–HMF-20% showed the best performance with a high tensile strength of 51.9 MPa and notable toughness of 167.6 MJ m–3. The thermally reversible DA reaction endowed PUA materials with excellent repair and recycling properties. The cut pieces can be reformed into a complete film during hot pressing and solvent reprocessing. Due to the existence of the phosphorus-containing structure, PUA–HMF elastomers also exhibited excellent self-extinguishing capability, while PUA–HMF-40% showed the highest limiting oxygen index (LOI) value of 27% and reached a V-0 rating in the UL-94 vertical burning test. In the cone test, both the peak heat release rate (PHRR) and total heat release (THR) values of the PUA–HMF samples were significantly reduced. This work provides a promising strategy to expedite high-performance sustainable advanced elastomers and expand the industrial application.
研究领域:
高分子材料科学
·
功能高分子
·
可持续材料
·
阻燃材料
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再生化学
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智能材料
·
绿色化学
✓ 已验证
产品关联
DOI
高影响因子
Smart Materials and Structures
·
2022
·Vol. 32
·期 1
·015017
·
IF 4.131
Haibing Zeng,Silian Fu,Yongri Liang,Li Liu
Polyurethane elastomers as a type of electroactive polymers have wide applications in soft actuators, soft sensors and energy harvesting due to their high dielectric constant, high electrostriction coefficients, easy processing and structure adjustability, and superior biocompatibility etc. However, the relationship between microstructure and electromechanical properties of EAEs has not been fully understood. In this work, we fabricated the branch structured poly(urethane–urea) elastomers (PUUs) using hydroxy-terminated polybutadiene as soft segment, isophorone diisocyanate and 4,4-diaminodicyclohexylmethane as hard segment, and hydroxyl-terminated four-armed polycaprolactone (PCL410) as branch structured chain extender for improving bending actuation performances, and understanding the relationship between structure and electromechanical properties. The degree of branched structure of PUUs were adjusted by the content of PCL410. The microphase separation kinetics of PUUs was enhanced as increase of PCL410 content, whereas the degree of microphase separation and hard domain size of PUUs were reduced. The mechanical loss and bending actuation stress of PUUs were significantly improved by incorporation of small amount of branched structure into PUU chains. The PUU with 2.60 mol.% of PCL410 showed 5.16 mm of bending displacement and 5.16 Pa of bending actuation stress at 7.2 kV (corresponding to 180 V mm−1 of the nominal electric field), which were 76.3, and 79 times higher than that of PUU without PCL410, respectively. The electric field induced bending actuation mechanism of branch structured PUUs was suggested that the bending actuation mechanism of branch structured PUUs is caused by electrostrictive effect from dipole orientation induced bending deformation of constrained segments and asymmetric charge density distribution on both anode and cathode sides of PUU films. Our results can provide new insight on design novel electroactive polyurethane elastomers.
研究领域:
材料科学
·
聚合物科学
·
电活性聚合物
·
软驱动器
·
机械工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）