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
Polymers
·
2022
·Vol. 14
·期 9
·1674
·
IF 4.967
Jingjing Bi,Yifan Liu,Jiaxu Liu
The article below describes a simple methodology to prepare cost-effective biodegradable poly(ester urethane)s (PEUs) with ordered hard segments (OHS) for medical application as long-term implants. A low-cost diurethane diol (1,4-butanediol-hexanediisocyanate-1,4-butanediol, BHB) was first designed and synthesized. Consequently, the BHB was employed as a chain extender to react with NCO-terminated poly(ε-caprolactone) to obtain PEUs. The molecular structural formats for BHB and PEUs were defined through NMR, FT-IR, and MS together with GPC, while the influence of OHS content on physical/chemical features for casted PEU films was investigated. The introduction of OHS could contribute to forming denser hydrogen-bonds, and consequently produce a compact network structure, resulting in great tensile capacity, low water absorption, and slow hydrolytic degradation rate by PEU films. PEU-2.0 films, which possessed the highest OHS content within PEUs, exhibited 40.6 MPa tensile strength together with 477% elongation at break, 4.3 wt % equilibrium water absorption and only 29.5% weight loss post-12 months’ degradation. In addition, cytotoxicity analysis of film extracts indicated that the cell viability of all PEUs containing OHS exceeded 75%, indicating good cytocompatibility. Due to outstanding tensile features, high biostability, nontoxic and absorbable degradation products and acceptable cytocompatibility, the cost-effective materials exhibited promising applications in the field of long-term implants.Keywords:poly(ester urethane)s;cost-effective;bio-degradable;ordered hard segments
研究领域:
材料科学
·
生物医学工程
·
组织工程
✓ 已验证
产品关联
DOI
PubMed
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
·
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
·
绿色化学
✓ 已验证
DOI
高影响因子
FARADAY DISCUSSIONS
·
2016
·Vol. 196
·43-54
·
IF 3.544
Kun Wang,Jiping Yang,Chen Gong,Hao Lu
An amino-terminated poly(propylene glycol)-modified tetraaryl-buta-1,3-diene derivative (TABDAA) was introduced to synthesize polyurethanes with different ratios of soft/hard segments. A mixture of TABDAA and poly(tetrahydrofuran) 1000 as the soft segments was reacted with 4,4-diphenylmethane diisocyanate and 1,4-butanediol as the hard segments in molar ratios of 1 : 2 : 1, 2 : 3 : 1, and 3 : 4 : 1 to give the desired polyurethanes named TMPU-211, TMPU-321 and TMPU-431, respectively. The three polyurethanes exhibited different aggregation-enhanced emission (AEE) behaviors because of their different soft/hard segment ratios. The polyurethanes with a higher soft segment content tended to form bigger particles in a DMF/water mixture solution, thus causing a sharper increase in their fluorescence intensity. In addition, the polyurethane films exhibited different fluorescence intensities after different heat treatments. After a quenching treatment of the soft segments in the polyurethane films, the fluorescence intensity dropped greatly. When these quenched polyurethane films were thermally annealed at 60 °C for 24 hours, their fluorescence intensity exceeded the initial intensity of the as-prepared films. Differential scanning calorimetry results showed that the polyurethane films in the quenched condition did not present the endothermal melting peak of the soft segments, and the melting peaks appeared again after thermal annealing. AFM experiments showed that an ordered arrangement was achieved after the heat treatment of these AEE polyurethane films. These results demonstrated that the polymer structure had a significant effect on the AEE properties of the polyurethane films, and more importantly, it is of great significance in improving the fluorescence emission of the AEE polymers and also for their potential application in fluorescent probes, stimuli-responsive materials, PLED devices and so on.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
GREEN CHEMISTRY
·
2016
·Vol. 18
·期 12
·3614-3619
·
IF 8.506
Zhong Ying,Chaoyong Wu,Shan Jiang,Ruhui Shi,Bin Zhang,Chao Zhang,Fengyu Zhao
A series of thermoplastic polyurethane-ureas were synthesized from a soft segment of a polycarbonate diol and a hard segment of an oligourea, and both the segments were derived from the CO2-route. The chemical structure of the synthesized segments and final polyurethane-ureas were identified by FT-IR and 13C-NMR. The average molecular weight of the oligourea was detected by potentiometric titration, MALDI-TOF and GPC. The Mn and Mw of the final polyurethane-ureas were nearly 0.7 × 104 Da and 1.0 × 104 Da, respectively, within a polydispersity index (PDI) of 1.27–1.44. Moreover, the X-ray diffraction (XRD) results showed that the as-synthesized polyurethane-ureas were amorphous and presented moderate thermo-stable properties with an initial decomposition temperature higher than 170 °C and a maximum decomposition temperature around 250 °C as examined by TGA. Furthermore, the amorphous polyurethane-ureas have a good solubility in some traditional organic solvents because the siloxane and carbonate groups were introduced into the main chain. The present novel polyurethane-urea, which possesses a high flexibility and fine compatibility with other polymeric materials, will have a wide application as a macromolecular plasticizer in plastic 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
PROGRESS IN ORGANIC COATINGS
·
2025
·
IF 7.3
Qingqing Shen,Zeng Wang,Haijun Xu,Junmin Wan
A novel waterborne polyurethane flame retardant, featuring co-modification with both soft and hard segments, was synthesized utilizing isophorone diisocyanate (IPDI), polyethylene glycol (PEG, Mn = 300), phosphorus poly alcohol (Exolit OP550), 2,2-dihydroxymethylpropionic acid (DMPA), phosphinylidynetrimethanol (THPO). The optimal conditions for the reaction were meticulously explored: 60 wt% OP550 in polyol, R = 1.6, 10 wt% THPO, and 5 wt% DMPA in prepolymer. Under these conditions, the flame retardant effect was exceptionally ideal, achieving a limiting oxygen index (LOI) of 28 % for the latex film and an even higher LOI of 30 % for the treated polyester fabrics. TG-FTIR analysis demonstrated that FRWPU60 had a positive effect on the flame retardant performance in the gas phase. CONE analysis further revealed that FRWPU60 altered the burning mode of polyester at high temperatures exhibiting both condensed-phase and gas-phase flame retardant mechanisms. Specifically, the total heat release (THR) and peak heat release rate (HRR) values of the FRWPU60-treated polyester fabrics were lower than those of the control samples. Based on the comprehensive analysis results, we proposed the flame retardant mechanism. The mechanisms involved capturing radicals generated by combustion, synergistically promoting charring, and inhibiting heat transfer. These mechanisms collectively contributed to the exceptional flame retardant properties of the FRWPU60-treated polyester fabrics.
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
MACROMOLECULAR CHEMISTRY AND PHYSICS
·
2021
·Vol. 222
·期 10
·2000439
·
IF 2.527
Shikai Hu,Tao Shou,Guoqing Fu,Xiuying Zhao,Zhao Wang,Liqun Zhang
The high content and regular distribution of hard segment (HS) are necessary to achieve high-performance thermoplastic polyurethane (TPU), and the HS unit of TPU is generated from the reaction of diisocyanate and chain extender. However, the traditional chain extenders are mainly aliphatic diol that cannot provide rigid groups to improve polyurethane performances. Herein, a novel chain extender bis(hydroxyethyloxycarbonylamino)hexane (BHH) that contains two urethane groups is designed and used to construct high-performance TPU by increasing content and regular distribution of HS. BHH is synthesized using ethylene carbonate (EC) and hexamethylenediamine (HDA) via a ring-opening reaction. Subsequently, the effect of BHH on the polyurethane performances is studied with respect to a typical TPU by using polytetramethylene ether glycol (PTMG) and hexamethylene diisocyanate (HDI) as the starting materials. The amount of HDI considerably differs for each polyurethane, aiming to ensure the same total content of urethane groups. When compared with the traditional ethylene glycol-extended polyurethane, the size and distribution of the HS domains of the BHH-extended polyurethane are obviously more homogeneous, which proves BHH-extended polyurethane has better microphase separation. Furthermore, ordered hydrogen bonding, the mechanical properties, and heat-resistance performance are significantly improved, suggesting a potential method to design TPU delivering outstanding 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
COMPOSITES SCIENCE AND TECHNOLOGY
·
2017
·
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 SOLID STATE ELECTROCHEMISTRY
·
2017
·Vol. 22
·期 4
·1109-1121
·
IF 2.316
Ren Naiqing,Song Youxin,Tao Can,Cong Bing,Cheng Qin,Huang Yiping,Xu Gewen,Bao Junjie
A series of waterborne polyurethane (WPU) with various hard segment and soft segment content were synthesized by hexamethylene diisocyanate (HDI), polyethylene glycol (PEG), dimethylol propionic acid (DMPA), and diethylene glycol (DEG). An increase in hard segment content decreased the crystallinity and thermal stability of WPU. Solid polymer electrolytes (SPEs) were prepared by complexing the as-prepared WPU with LiTFSI. The ionic conductivity increased first with the increasing of the hard segment content and then decreased. The compatibility of WPU-based SPEs with lithium electrode was influenced by the hard segment content. The electrochemical stability windows for all the SPEs have reached around 5.0 V (vs. Li + /Li) at 60 °C. A maximum ion conductivity of 5.14 × 10 −5 S cm −1 at 25 °C was found for WPU12-20%Li and 1.29 × 10 −3 S cm −1 at 60 °C for WPU12-25%Li. All-solid-state LiFePO 4 /SPE/Li battery based on WPU12-20%Li electrolyte delivered discharge specific capacities of 159 and 162 mAh g −1 under 60 and 80 °C at 0.1 C, respectively. Tuning the appropriate hard and soft segment composition of WPU may ultimately lead to the successful use of WPU-based SPEs for all-solid-state lithium ion batteries.
研究领域:
材料科学
·
能源科学
✓ 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
危险品化学品经营许可证（带存储）