Polymers
·
2022
·Vol. 14
·期 10
·2039
·
IF 4.967
Ziyun Shen,Liuchun Zheng,Danqing Song,Yi Liu,Chuncheng Li,Jiajian Liu,Yaonan Xiao,Shaohua Wu,Tianbo Zhou,Bo Zhang,Xuedong Lv,Qiyong Mei
A series of non-isocyanate poly(ether urethane) (PEU) were prepared by an environmentally friendly route based on dimethyl carbonate, diols and a polyether. The effect of the chemical structure of polyurethane hard segments on the properties of this kind of PEU was systematically investigated in this work. Polyurethane hard segments with different structures were first prepared from hexamethylene di-carbamate (BHC) and different diols (butanediol, hexanediol, octanediol and decanediol). Subsequently, a series of non-isocyanate PEU were obtained by polycondensation of the polyurethane hard segments with the polyether soft segments (PTMG2000). The PEU were characterized by GPC, FT-IR,1H NMR, DSC, WAXD, SAXS, AFM and tensile testing. The results show that the urea groups generated by the side reaction affect the degree of crystallization of hard segments by influencing the hydrogen bonding of the hard segments molecular chains. The degree of hard segment crystallization, in turn, affects the thermal and mechanical properties of the polymer. The urea group content is related to the carbon chain length of the diol used for the synthesis of hard segments. When butanediol is applied to synthesize hard segment, the hard segment of the resulting PEU is unable to crystallize. Therefore, the tensile strength and modulus of elasticity of butanediol-based PEU is lowest among three, though it possesses the highest urea group content. When longer octanediol or decanediol is applied to synthesize the hard segment, the hard segments in the resulting polyether-based polyurethane are crystallizable and the resulting PEU possesses higher tensile strength.Keywords:non-isocyanate;poly(ether urethane);hard segment
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2023
·
IF 9.5
Jiadong Wang,Min Wang,Xi Zhang,Yang Han,Yingxue Wu,Dong Wang,Xuan Qin,Yonglai Lu,Liqun Zhang
Polyurethane (PU) with microphase separation has garnered significant attention due to its highly designable molecular structure and a wide range of adjustable properties. However, there is currently a lack of systematic approaches for quantifying PU’s microphase separation. To address this research gap, we utilized an atomic force microscopy (AFM) nanomechanical mapping technique along with Gaussian fitting to recolor and quantitatively analyze the evolution of PU’s microphase separation. By varying the ratios of the chain extender to cross-linking agent, we observed the changes in the hydrogen bonding between the soft and hard segments. As the ratio of the chain extender to cross-linking agent decreases, the strength of the hydrogen bonding weakens, resulting in a reduction in the quantity and phase percentage of hard segment (HS) domains. Consequently, the degree of microphase separation between the soft and hard segments decreases, leading to specific alterations in the material’s mechanical properties and dynamic viscoelasticity. To further investigate the hierarchical structure of PU, we employed various techniques, such as X-ray analysis, transmission electron microscopy (TEM), and AFM-based infrared spectroscopy (AFM-IR). Our findings reveal a spherulite pattern composed of lamellae within the HS domains, with the cross-linking density gradually increasing from the center to the periphery. Overall, our comprehensive characterization of PU provides valuable insights into its hierarchical structure and establishes a quantitative framework to explore the intricate relationship between the structure and properties.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHINESE JOURNAL OF POLYMER SCIENCE
·
2025
·
IF 4
Jin Guang-Zhi,Chen Le-Hang,Gong Yu-Zhen,Li Peng,Wang Run-Guo,Li Fan-Zhu,Lu Yong-Lai
The fatigue resistance of casting polyurethane (CPU) is crucial in various sectors, such as construction, healthcare, and the automotive industry. Despite its importance, no studies have reported on the fatigue threshold of CPU. This study employed an advanced Intrinsic Strength Analyzer (ISA) to evaluate the fatigue threshold of CPUs, systematically exploring the effects of three types of isocyanates (PPDI, NDI, TDI) that contribute to hard segment structures based on the cutting method. Employing multiple advanced characterization techniques (XRD, TEM, DSC, AFM), the results indicate that PPDI-based polyurethane exhibits the highest fatigue threshold (182.89 J/m 2 ) due to a highest phase separation and a densely packed spherulitic structure, although the hydrogen bonding degree is the lowest (48.3%). Conversely, NDI-based polyurethane, despite having the high hydrogen bonding degree (53.6%), exhibits moderate fatigue performance (122.52 J/m 2 ), likely due to a more scattered microstructure. TDI-based polyurethane, with the highest hydrogen bonding degree (59.1%) but absence of spherulitic structure, shows the lowest fatigue threshold (46.43 J/m 2 ). Compared to common rubbers (NR, NBR, EPDM, BR), the superior fatigue performance of CPU is attributed to its well-organized microstructure, polyurethane possesses a higher fatigue threshold due to its high phase separation degree and orderly and dense spherulitic structure which enhances energy dissipation and reduces crack propagation.
研究领域:
材料科学
·
力学
✓ 已验证
产品关联
DOI
高影响因子
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
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弹性体性能研究
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2024
·
IF 2.7
Shan Jiang,Tianyi Han,Tongshuai Tian,Chuanqing Yang,Li Liu
Compared with isocyanate-based polyurethanes (PUs), poly(hydroxyurethane)s (PHUs) are more likely to form phase mixing structure, inducing poor elastic properties. To avoid this, stronger interaction between hard segments is required. Herein, carbon dioxide-based poly(hydroxyurethane-urea)s (PHUUs) with different hard segment contents were prepared through polyaddition reaction using 5-membered dicyclic carbonate (BADC) as hard segment, poly(propylene glycol) bis(2-aminopropyl ether) (D2000) as soft segment, and amino-terminal polyurea oligomer (HMDA*) chain extender, and several PHUs were prepared by using hexamethylenediamine (HMDA) chain extender or without using chain extender as controls. The interaction between hard segments were strengthened with the introduce of chain extender. Compared with PHUs, PHUUs with HMDA* chain extender were more inclined to form significant microphase separation. For PHUUs, the hard segment T g appeared at around 60°C when hard segment content reached 40 wt%, and the interdomain spacings were in the range of around 14–23 nm with 40–50 wt% hard segment content. In addition, PHUUs exhibited better solvents resistance and mechanical properties than PHUs with the same hard segment content. PHUUs with certain hard segment content showed good elastic recovery, with a residual strain less than 2% after 10 cycles, which comparable with conventional isocyanate-based PUs.
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
Hangtian Zhang,Fang Zhang,Yixian Wu
Thermoplastic polyurethane (TPU) elastomers based on polyoxytetramethylene glycol (PTMG) with 2000 g·mol–1 as soft segments (SSs) and isocyanates as well as their reaction with butanediol as hard segments (HSs) were synthesized. The three-dimensional supramolecular networks were constructed in TPU by the formation of physical HSs-rich domains via microphase separation, hydrogen bonding, and microcrystallization, which are dominated by the chemical structure of HSs. The robust stretchable TPU with an excellent tensile strength of 32 MPa and elongation of 1378% at break could be successfully prepared, and no crystallization happened to keep the elasticity even at a low temperature (−90 °C) when the steric semisymmetric bis(4-isocyanatocyclohexyl)methane (HMDI) was introduced into HSs-rich domains. The crystallinity and ordered hydrogen bonding content decreased in HSs-rich domains with increases in steric hindrance and asymmetry of diisocyanates. A new approach was developed to construct the high-performance TPUs by introducing long PTMG SSs for the flexibility and elasticity and steric semisymmetric HMDI hard segments.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
高影响因子
Journal of Materials Research and Technology-JMR&T
·
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
·
力学
✓ 已验证
产品关联
DOI
高影响因子
Polymer Chemistry
·
2018
·Vol. 9
·期 7
·869-877
·
IF 4.927
Bo Pang,Jingzhe Zhang,Minglei Pang,Peijian Zhao,Zhen Yang,Shengyu Feng,Jie Zhang
A new synthesis strategy was presented to prepare a polyurea–polysiloxane–polyether copolymer (PUA). A new block soft segment (b-SS) was synthesised via an aza-Michael addition reaction of acryloxymethyl-terminated polydimethylsiloxane (AT-PDMS) and amine-terminated polyoxypropylene (PPO). The hard segment (HS) was formed from bis(4-isocyanato cyclohexyl)methane (HMDI) and a 2-methyl-1,5-diaminopentane chain extender. The copolymers are tough and easily processed thermoplastic elastomers. The properties and structures of the polyurea–polysiloxane–polyether copolymers were investigated by dynamic mechanic analysis (DMA), small angle X-ray scattering (SAXS), atomic force microscopy (AFM) and macroscopy mechanical testing. The DMA results of the polyurea–polysiloxane–polyether copolymers show that temperature insensitive rubbery plateaus exist between −50 °C and 80 °C, which are independent of the HS wt% and the molecular weight of PDMS. The viscoelastic behavior of the polyurea–polysiloxane–polyether copolymers was correlated with the molecular weight of PDMS used for the b-SS. The polyurea–polysiloxane–polyether copolymers display improved mechanical strength (16 MPa) compared with the published results of PDMS-based siloxane-urea segmented copolymers (11–13 MPa). The studies reveal that the mild microphase separation between the hard and soft segments leads to improved mechanical strength of the polyurea–polysiloxane–polyether copolymers. In addition, for these copolymers, the introduction of b-SS is effective in avoiding a sharp phase separation assuming that the molecular weight of PDMS in the b-SS is appropriate.
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
Polymers
·
2019
·Vol. 11
·期 5
·838
·
IF 3.164
Ting Li,Tianze Zheng,Jiarui Han,Zhanli Liu,Zhao-Xia Guo,Zhuo Zhuang,Jun Xu,Bao-Hua Guo
Four linear polyurea elastomers synthesized from two different diisocyanates, two different chain extenders and a common aliphatic amine-terminated polyether were used as models to investigate the effects of both diisocyanate structure and aromatic disulfide chain extender on hard segmental packing and self-healing ability. Both direct investigation on hard segments and indirect investigation on chain mobility and soft segmental dynamics were carried out to compare the levels of hard segmental packing, leading to agreed conclusions that correlated well with the self-healing abilities of the polyureas. Both diisocyanate structure and disulfide bonds had significant effects on hard segmental packing and self-healing property. Diisocyanate structure had more pronounced effect than disulfide bonds. Bulky alicyclic isophorone diisocyanate (IPDI) resulted in looser hard segmental packing than linear aliphatic hexamethylene diisocyanate (HDI), whereas a disulfide chain extender also promoted self-healing ability through loosening of hard segmental packing compared to its C-C counterpart. The polyurea synthesized from IPDI and the disulfide chain extender exhibited the best self-healing ability among the four polyureas because it had the highest chain mobility ascribed to the loosest hard segmental packing. Therefore, a combination of bulky alicyclic diisocyanate and disulfide chain extender is recommended for the design of self-healing polyurea elastomers.Keywords:diisocyanate structure;disulfide bonds;hard segmental packing;self-healing;polyureas
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
PubMed
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
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
International Journal of Polymeric Materials and Polymeric Biomaterials
·
2017
·
IF 1.515
Qi Jia,Yiran Xia,Shengnan Yin,Zhaosheng Hou,Ruxia Wu
This work describes the preparation, characterization, mechanical properties, in vitro degradability, and cytocompatibility of two aliphatic segmented polyesterurethanes (SPEU-II, SPEU-III) based on poly(ε-caprolactone-co-L-lactide) and aliphatic urethane diisocyanate chain extenders. Two novel chain extenders containing two and four urethane groups, respectively, were synthesized and used in SPEU formulation. The influences of well-defined hard segment length on the degradability and mechanical properties of SPEU films were researched. The results of differential scanning calorimeter and X-ray powder diffraction showed that the long well-defined hard segments improved the phase separation of soft and hard segments, which led to satisfactory mechanical properties of SPEU films (ultimate stress: 24.8–35.4 MPa; strain at break: 601–669%). And the initial modulus increased from 31.9 MPa (SPEU-II) to 41.7 MPa (SPEU-III) with the increasing length of hard segments. SPEU-III with longer well-defined hard segment containing more urethane groups exhibited slower hydrolytic degradation rate (∼67 days) and lower water absorption (∼4 wt%) than SPEU-II. The results could be due to the formation of more hydrogen bonds among the hard segments and between the soft and hard segments, which strengthened the interchain attraction and gave a more compact network structure. The SPEU films showed similar thermostability, indicating that the length of hard segments marginally affects the thermostability. Cytotoxicity test of film extracts was conducted using L929 mouse fibroblasts, and the relative growth rate exceeded 90% after incubation for 24, 48, and 72 h, showing excellent cytocompatibility.
研究领域:
生物材料学
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医学工程
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高分子化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2015
·Vol. 51
·期 5
·2727-2738
·
IF 2.371
Wu Xiwen,Liu Libin,Fang Wenyuan,Qiao Congde,Li Tianduo
Abstract In this work, we synthesized two kinds of polyurethanes with azobenzene as hard segments in the side chains and in the main chains. Their thermal stabilities were high enough for their shape memory application. For polyurethane with azobenzene in the side chain (PU), the azobenzene has more distinctly effect on inhibiting crystallization of polycaprolactone (PCL) because of irregular orientation of azobenzene. For polyurethane with azobenzene in the main chain (PUR), the crystallinity of PCL is mainly affected by its molecular weight. PU-3500 and PUR-3500 exhibit perfect shape fixing ability of 99 % with recovery ratio of 98 % at 50 % strain. The recovery ratio is decreased for PU-3500 and increased for PUR-3500 as the applied strain increased. The mechanism of the hard segment structures effect on the shape memory behavior is briefly discussed. Importantly, the two molecules behave trans–cis isomerization under UV irradiation. This work is crucially important for the structural design of shape memory polyurethane and applications in the smart devices. Graphical Abstract
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
危险品化学品经营许可证（带存储）