COLLOID AND POLYMER SCIENCE
·
2025
·
IF 2.3
Yan Zhixiang,Yang Peiqi,Yang Huiting,Zheng Shuo,Tan Zhiyong
With the development of flexible electronics and smart devices, the performance of high-dielectric polyurethane materials is more demanding, and an in-depth understanding of the relationship between their structure and dielectric properties is crucial for material design. In this work, a series of polyurethane materials with different hard segment content were synthesized, using poly(tetramethylene ether)glycol (PTMG) and poly(carbonate diol) (PCDL) as the soft segments, and 4,4′-diphenylmethane diisocyanate (MDI) and 1,4-butanediol (BDO) as the hard segments. The effects of hard segment content on the microphase separation, mechanical properties, and dielectric properties of the polyurethane were systematically investigated. The results revealed that with increasing hard segment content, the degree of microphase separation, tensile strength, and dielectric constant of the polyurethane all increased. Among them, the sample with a hard segment content of 55% (PU-55%) exhibited the best overall performance and exhibited the most pronounced microphase separation, with a dielectric constant of 10.50 at 10 2 Hz and a tensile strength of 18.33 MPa. In addition, it was found that N,N-dimethylformamide (DMF) produces dipole–dipole interactions with precursor molecules (MDI, PTMG, and PCDL) during the synthesis process, thereby modulating the polarity of the reaction environment. This work provides meaningful guidance for structure modulation and performance optimization of polyurethane materials. Graphical abstract
研究领域:
高分子材料科学
·
介电材料
·
弹性体性能研究
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Research and Technology-JMR&T
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2025
·
IF 6.6
Guangzhi Jin,Peng Li,Yuzhen Gong,Yu Wang,Runguo Wang,Fanzhu Li,Yonglai Lu
The microstructure of casting polyurethane (CPU) affects its performance under high dynamic loads, which is critical for developing high-performance materials. Herein, NDI-based casting polyurethane materials with varying hard segment contents (20%, 30%, 40%) were synthesized, and their behaviors under tensile fatigue (a strain amplitude of 100%, a frequency of 10 Hz, and up to 50,000 cycles) was investigated. As the number of fatigue cycles increased, the applied load required to achieve the same strain decreased, primarily due to stress softening and plastic deformation in the CPU. Microstructural analysis revealed a reduction in hydrogen bonding degree, leading to a decrease in structural regularity and an increase in defects. Atomic force microscopy (AFM) images revealed that the hard segments gradually integrated into the soft segment matrix, which reduced the content of high- and medium-modulus phase regions and correspondingly increased the low- modulus phase region. Transmission electron microscopy (TEM) images clearly suggested the destruction process of the spherulites, in which the crystallization structure deteriorated more significantly after fewer cycles in CPUs with higher hard segment content. The crystallinity, long period, and transition layer thickness of the CPUs demonstrated a decreasing trend with increasing fatigue cycles. This study provides valuable insights into the performance of CPUs under dynamic loading, laying a theoretical foundation for designing durable, and fatigue-resistant materials.
研究领域:
材料科学
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力学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2017
·Vol. 7
·期 88
·55610-55619
·
IF 3.108
Dong Xiang,Miao Liu,Guanliang Chen,Teng Zhang,Li Liu,Yongri Liang
In this work, we fabricated novel poly(urethane–urea) (PUU)-based dielectric elastomers using a hydroxyl-terminated butadiene–acrylonitrile copolymer (HTBN) as the soft segment and hexamethylene diisocyanate (HDI) and 3,3′-dimethyl-4,4′-diamino dicyclohexyl methane (DMDC) as hard segments. The effect of hard segment (HS) content on the hard domain (HD) structure, morphology, dielectric and mechanical properties was investigated with Fourier transform infrared spectroscopy (FTIR), small/wide angle X-ray scattering (SAXS/WAXS), broadband dielectric spectroscopy and mechanical testing methods. Our results indicated that the hard domain structure units of PUUs such as degree of hydrogen bonding, size and crystallinity played an important role in the dielectric and mechanical properties. The dielectric constant of PUUs was significantly decreased with increasing HS content, whereas the breakdown strength and Young's modulus of PUUs were significantly increased. The relationship between multi-length scale structure and dielectric constant and breakdown strength properties of PUUEs were discussed. Our results can provide a new insight for optimization of dielectric and mechanical properties of PUU-based dielectric elastomers.
研究领域:
材料科学
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高分子化学
✓ 已验证
产品关联
DOI
高影响因子
EUROPEAN POLYMER JOURNAL
·
2022
·
IF 5.546
Zhihua Shen,Jialiang Chen,Gefei Li,Gaohua Situ,Xiaofeng Ma,Ye Sha,Dong Zhao,Qun Gu,Meng Zhang,Yanlong Luo,Zhenyang Luo
It has been a challenge to impart high strength and toughness to room-temperature self-repairing polyurethane/polyurea materials. We report a room-temperature self-repairing thermoplastic polyurea elastomer (PU) with mechanical robustness. When thiosemicarbazide was used as a chain extender, strong (or weak) hydrogen bonds were formed between C O (or C S) and N H groups in the hard regions of PU. The results were optimized mechanical and self-repairing properties: the tensile strength, elongation at break, toughness, and self-repairing efficiency of the PU reached 4.43 MPa, 1498.37%, 55.14 MJ m −3 , and 96.3%, respectively. We found that the increase of hard segments led to increased/decreased number of ordered/disordered hydrogen bonds, as well as enhancement of both the aggregation of hard segments and the degree of microphase separation. We proposed a model dealing with the relation between the hard segment content and the hydrogen-bonding arrays and explored the exchange rate and the order–disorder transition of hydrogen bonds, to provide an insight into the optimization of mechanical and self-repairing properties.
研究领域:
材料科学
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化学
✓ 已验证
产品关联
DOI
高影响因子
MACROMOLECULAR MATERIALS AND ENGINEERING
·
2025
·
IF 4.6
Mingping Zhou,Jiaqiang Xiong,Dingzhe Che,Qiang Wu,Shichao Zhang,Denghui Wang,Fei Gao,Zheng Zhang,Jiping Yang
In protective applications, polyurethane (PU) is a key material, yet the microstructural mechanisms governing its dynamic mechanical properties are not well understood. This study investigates the influence of hard segment content on the low strain rate compression and high strain rate impact properties of waterborne polyurethane (WPU) by modulating the NCO/OH ratio. Mechanical responses are characterized using a universal testing machine and a split Hopkinson pressure bar (SHPB) system. Additionally, the hydrogen bonding and microphase separation structure are analyzed using FTIR, DSC, DMA, and SAXS. These findings reveal that the glass transition temperatures ( T g DSC and T g DMA ) shift toward higher temperatures with increasing hard segment content, which is attributed to the intensified hydrogen bonding cross-linked network, as corroborated by FTIR and SAXS analyses. The WPU demonstrates a pronounced strain rate sensitivity across a broad range of strain rates (10 −4 –10 4 s −1 ). Notably, the 45 wt.% hard segment WPU523 sample shows heightened sensitivity, attributed to complex hydrogen bonding heterogeneity and a higher Herman's orientation factor during loading, the key to WPU's dynamic mechanical response.
研究领域:
材料科学
·
力学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2021
·Vol. 139
·期 18
·52059
·
IF 3.125
Xi Hou,Liwen Sun,Wei Wei,Darlene K. Taylor,Shengpei Su,Haibin Yu
Thermoplastic polyurethane (TPU) has become the focus of attention in the green and sustainable materials field because of its superior processability and recyclability. In this paper, a series of polylactic acid (PLA) and polycaprolactone (PCL)-based TPUs were successfully prepared by selecting PLA glycol, PCL glycol, isophorone diisocyanate (IPDI) and 1,4-butanediol (BDO) through a one-step polymerization method. The properties of the PLA and PCL-based TPUs are comprehensively characterized by Fourier transform infrared spectroscopy, 1 H NMR spectra, gel permeation chromatography, differential scanning calorimetry, thermalgravimetric analyzer, tensile test, dynamic mechanical analysis, scanning electron microscope, and so forth. The effect of hard segments content and PLA glycol molecular weight on the properties of PLA and PCL-based TPUs was systematically studied. Notably, their performance shows a certain degree of regularity and can be controlled by adjusting the hard segments content or the molecular weight of the PLA glycol. The prepared PLA and PCL-based TPUs have a tensile strength of 24.71 MPa, excellent thermal stability and out-standing damping performance. Its tan δ max of 1.40 and an effective damping temperature range of 50°C also make it a green damping material with great potential.
研究领域:
材料科学
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绿色化学
✓ 已验证
DOI
高影响因子
COMPOSITES SCIENCE AND TECHNOLOGY
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2017
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IF 4.873
Congmei Lin,Qiang Tian,Keping Chen,Guansong He,Jianhu Zhang,Shijun Liu,László Almásy
In this research, a group of segmented polyurethane (PU) copolymers with different hard segment (HS) contents were successfully synthesized. The microstructure of the PU copolymers was characterized via Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), and small-angle neutron scattering (SANS). Then, the PU copolymers were selected as polymer binder for coating an insensitive high explosive 1,3,5-triamino-2,4,6-trinitrobenzene (TATB) to prepare polymer bonded explosives (PBXs). When the HS concentration of PU copolymers increased from 14 to 34 wt %, a 14.6 times increase in the creep rupture time of PBXs under 60 °C/3 MPa and a 52.3% decrease in the steady-state creep strain rate under 60 °C/1 MPa were observed. The experimental results indicated that a wide variety of structure and properties of PU copolymer could be customizable through the adjustment of the HS contents, and consequently, provided an efficient route to tune the creep performance of the PBXs over a wide range.
研究领域:
材料科学
·
爆炸物工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2024
·
IF 2.7
Xu Han,Zhijian Pan,Le Chang,Yumei Ji,Zeqian Wang,Feng Liu
The degree of microphase separation plays a vital role in one-component polysulfide adhesives determining their mechanical properties and thermal stability. However, the degree of microphase separation was mainly determined by the hard segment content and molecular weight of liquid polysulfide. In this work, we successfully prepared a series of one-component polysulfide adhesives with 30 wt%–50 wt% hard segment content by using 4,4-diphenylmethane diisocyanate (MDI), different molecular weights (1000, 2500, and 4000 g/mol) of liquid polysulfides (JLY-121/1225/124) and 1,4-butanedithiol (BSO), and systematically investigated the relationship between microphase separation and material's properties. The results revealed that higher hard segment content and larger molecular weight of liquid polysulfide contributed to forming a higher degree of microphase separation, respectively. Among them, the optimal mechanical properties and thermal stability were obtained at 40 wt% hard segment content when JLY-1225 (2500 g/mol) was used. After immersion in the oil and water for 21 days, the tensile strength of C 40 -1225 could still reach 16.99 ± 0.80 and 14.87 ± 0.30 MPa, with a tensile strength retention rate of 75.75% (oil) and 66.30% (water), confirming that one-component polysulfide adhesives had good solvent resistance.
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
POLYMER
·
2017
·
IF 3.684
Dong Xiang,Li Liu,Yongri Liang
Understanding the relationship between structure and dielectric property of dielectric elastomers (DEs) is very important in their practical applications. In this work, we fabricated polyurethane elastomers (PUEs) with high dielectric properties using hydroxyl-terminated butadiene-acrylonitrile copolymer (HTBN) as soft segment and hexamethylene diisocyanate (HDI) and butanediol (BDO) as hard segment (HS). We also investigated the effect of HS content on the structure, mechanical, dielectric and electromechanical properties of HTBN-based PUEs. The HTBN-based PUEs were achieved larger than 8.7 of dielectric constant and lower than 0.02 of dissipation factor at 1 KHz. The dielectric constant and dissipation factor of PUEs were slightly decreased with increase of HS segment, whereas the breakdown strength and Young's modulus of PUEs were significantly increased. The actuated area strain of PUEs also showed decreased with increase of HS content under the same electric field. Our results indicated that the adjusting of HD structure via HS content is one of effective ways to optimize the dielectric and mechanical properties of PUEs.
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
POLYMER TESTING
·
2025
·
IF 6
Boxin Liu,Zhihao Niu,Zhanglei Wang,Yimin Wang,Hua Zou,Xiuying Zhao,Shikai Hu
Thermoplastic polyurethane (TPU) possesses a distinctive microphase separation structure resulting from the thermodynamic incompatibility between its soft and hard segments. The content of hard segments is a significant factor that impacts the micromorphology and associated properties of TPU. In this study, hydroxyl-terminated polybutadiene thermoplastic polyurethanes (HTPB-TPUs) were synthesized using a two-step method in which hydroxyl-terminated polybutadiene, toluene diisocyanate, and 1,4-butanediol were incorporated. These HTPB-TPUs were designed to lack hydrogen bonding between the soft and hard segments. The structure and properties of the HTPB-TPUs were comprehensively evaluated. The results demonstrated a noticeable influence of the hard segment content on the degree of microphase separation. A combination of analytical techniques was employed to elucidate the effect of hard segment content on phase separation. Additionally, all-atom molecular dynamics simulations were conducted to determine the number of hydrogen bonds. These simulations served to verify the impact of the hard segment content on phase separation. Furthermore, the relationship between the hard segment content and the mechanical properties was elucidated by examining the phase separation phenomenon. This study provides valuable insights into the interaction between the structure and properties of TPU, laying a foundation for future investigations in this area.
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
JOURNAL OF APPLIED POLYMER SCIENCE
·
2012
·Vol. 128
·期 3
·2152-2161
·
IF 1.289
Qiheng Tang,Jiyu He,Rongjie Yang,Qingsong Ai
Reactive hot-melt polyurethane adhesive (RHMPA) is moisture-curing polyurethane (PU) adhesive whose main component is an isocyanate-terminated PU prepolymer that can be cured after application by reaction with ambient moisture. Two series of RHMP-containing poly(tetramethylene glycol) (PTMG) of different molecular weights and different degrees of polymerization of the hard segment have been successfully synthesized using a two-step bulk polymerization with 4,4′-diphenylmethane diisocyanate, PTMG, and 1,4-butanediol (1,4-BDO). The structure and basic properties of the RHMPA film have also been characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis, differential scanning calorimetry, dynamic mechanical analysis, atomic force microscopy, gel permeation chromatography (GPC), shore hardness ( A / D ), and tensile tests. The results show that the initial decomposition temperature is more than 250°C, and the tensile strength of the RHMPA film was greater than 15 MPa. The adhesive performance of the RHMPA with different hard-segment content was studied through studies of the single lap-shear strength and tensile strength of butt joints. The results show a general trend of the bonding strength increases with the hard-segment content at 25°C. The adhesive performance of RHMPA in different environments was also investigated. It was found that the RHMPA exhibited excellent bonding strength to thermoplastic polyurethane elastomer (TPU) when placed in the fridge at −20°C, hot water at 80°C, 1 M HCl solution (acid) at 25°C, and 1 M NaOH solution (alkaline) at 25°C for 10 h. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
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
JOURNAL OF APPLIED POLYMER SCIENCE
·
2017
·Vol. 135
·期 11
·45974
·
IF 1.86
Wenqi Xian,Lina Song,Baohua Liu,Hulan Ding,Zhao Li,Mengping Cheng,Le Ma
CO 2 copolymer diol-based thermal polyurethane elastomers (PPC-TPU) were prepared by the reaction of CO 2 copolymer diol and methylene diphenyl diisocyanate and chain extender (ethylene glycol/1,4-butanediol/1,6-hexanediol) (EG/BDO/HG). The rheological and mechanical properties of PPC-TPU were analyzed. The effects of shear rate, shear temperature, hard segment content, and variety of chain extender on the properties of PPC-TPU were studied. The results showed that the apparent viscosity (η) of PPC-TPU decreased with the increasing shear rate ( τ ), and the non-Newtonian index ( n ) was less than 1. PPC-TPU exhibited a typical character of pseudoplastic non-Newtonian rheological behavior. The degradation during the processing was obviously inhibited by adding plasticizer and antioxidant. It was also discovered that the apparent viscosity varied with the content of hard segment and chain extender. Under the same temperature (185 °C) and shear rate (50 s −1 ), the apparent viscosity increased considerably with the raise of hard segment content, and the apparent viscosity and tensile strength of PPC-TPU with EG as chain extender was the maximum. It can be seen that with the apparent shear rate increasing, the variation tendency of apparent shear stress levels off, and the nonlinear relationship of τ – γ curve tended to be obvious. PPC-TPU exhibited a typical character of pseudoplastic non-Newtonian rheological behavior. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135 , 45974.
研究领域:
高分子材料科学
·
流变学
·
功能高分子
·
生物基聚合物
·
材料力学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）