Materials Science & Engineering C-Materials for Biological Applications
·
2019
·
IF 4.959
Xiaolong Liu,Bing Yang,Zhaosheng Hou,Na Zhang,Yuanyuan Gao
The aim of this work is to provide a new kind of polyurethane with improved surface blood compatibility for long-term blood-contacting biomaterials. In the study, an aliphatic poly(ester-urethane) (H-PEU) with uniform-size hard segments was synthesized by one-step chain extension of poly(ε-caprolactone) (PCL) with diurethane diisocyanate (HBH), and biomimetic phosphorylcholine (PC) groups were immobilized onto the film surface with high grafting efficiency by three-step chemical treatments under mild reaction conditions. The H-PEU film was firstly treated with 1,6-hexanediisocyanate (HDI) to introduce -NCO groups on the surface (H-PEU-NCO) through an allophanate reaction; the -NCO groups were then coupled via a condensation reaction with one of -NH 2 groups of tris(2-aminoethyl)amine (TAEA) to immobilize -NH 2 on the surface (H-PEU-NH 2 ); finally, the double bond of 2-methacryloyloxyethyl phosphorylcholine (MPC) reacted with -NH 2 by Michael addition reaction to obtain MPC-grafted H-PEU (H-PEU-MPC). The modified surfaces were characterized by Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). The results verified that MPC was successfully grafted onto H-PEU surface with high grafting density. The blank and modified films showed similar crystallization behaviors, thermal stabilities and mechanical properties, indicating that the chemical treatments had minimum influence on the physicochemical properties of the substrate. The H-PEU-MPC displaying a much lower water contact angle (~15.2°) than H-PEU (80.3°) meant that the hydrophilic PC functional groups improved the surface hydrophilicity significantly. The surface blood compatibility was examined by bovine serum albumin adsorption and platelet adhesion tests, and the results revealed that H-PEU-MPC had improved resistance to protein adsorption and platelet adhesion capacity. The MPC-grafted H-PEU film possessed outstanding mechanical properties (ultimate stress: 36.1 MPa; strain at break: 883%), low protein adsorption quantity (1.33 μg/cm 2 ) and good anti-platelet adhesion capacity (582 ± 16 per mm 2 ), implying its high potential to be applied as biomaterials for vascular grafts, subcutaneously implanted devices or other blood-contacting devices.
研究领域:
生物材料
·
表面化学
·
生物医学工程
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Molecular Catalysis
·
2019
·
IF 2.938
Chaokun Yang,Yanglin Chen,Ping Xu,Li Yang,Jiaxu Zhang,Jianmin Sun
Multifunctional monocomponent zinc halide-based ionic liquids, amidinothiourea-ZnI 2 (ATUI) and N-phenylthiourea-ZnI 2 (NTUI), were facilely developed as homogeneous catalysts for efficient conversion of CO 2 with epoxides to cyclic carbonates. On account of synergistic effects of multifunctional components in ATUI, the propylene carbonate yield could reach 95% under 110 °C, 1.0 MPa, 4.0 h or even mild conditions. There was a slight decrease of propylene carbonate yield because of the loss of ATUI during the reuse process. Additionally, the universality of ATUI was also studied to other terminal epoxides. Meanwhile, a plausible reaction mechanism was proposed where the synergistic effects involving cation structure and halogen anion of ATUI guarantee the cycloaddition reaction to proceed effectively under solvent and co-catalyst free condition. Finally, reaction kinetics were undertaken to compare the catalytic efficiency of ATUI and NTUI so as to compare the catalytic activity of different numbers of hydrogen bond donor in amidinothiourea and N-phenylthiourea.
研究领域:
化学
·
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Plants-Basel
·
2023
·Vol. 13
·期 1
·10
·
IF 4.5
Yangyang Ma,Yiyu Pan,Bizeng Mao
Saffron (Crocus sativusL.), being one of the distinguished commercial spice crops in the world, is in demand for its culinary, colorant, and pharmaceutical benefits. In this study, a novel indirect somatic embryogenesis (SE) system was, thus, established for the study of this plant. To this end, firstly, the lateral buds were cultured. Then, the cultures were transformed using Murashige and Skoog (MS) medium supplemented with either 6-benzyladenine (BA: 5 and 10 mg/L), naphthalene acetic acid (NAA: 0, 1, and 2 mg/L), or trans-zeatin (tZ: 0, 0.5, and 1.0 mg/L), before being classified into four structures: white globular (WG), yellow compact nodular (YCN), yellow-brown fragile (YBF), and dark-brown porous (DBP). As soon as BA (10 mg/L) and NAA (2 mg/L) were added, elevated percentages of white globular calli (56.8%) and white globular calli (31.5%) structures were induced. Additionally, 6-benzyladenine (5 mg/L) and naphthalene acetic acid (1 mg/L) allowed the formation of yellow-brown fragile structures, and the combination of 6-benzyladenine (10 mg/L) with trans-zeatin (1 mg/L) formed the DBP structures. After three months, the white globular calli were incubated using the MS basal medium, before being augmented with thidiazuron (TDZ: 1 mg/L) and picloram (PIC: 2 mg/L), from which 60% of the cases matured into shoots and, ultimately, cormlets. Morphoanatomical analyses also showed that the white globular calli cells were closely arranged, as they had a dense cytoplasm, a significant vascular differentiation, and embryoids. Furthermore, the yellow compact nodular structures were characterized by a strong differentiation capacity and contained many meristematic cells with high caryomitosis centers. We observed that the yellow-brown fragile calli had looser cell arrangements, with a vascular structure located on the protoderm edge, while there was no obvious cellular arrangement in the dark-brown porous structures. The induction of the adventitious buds in vivo on the MS medium that was supplemented with thidiazuron and picloram accordingly demonstrated the highest rates (60%) of white globular calli.Keywords:Crocus sativus;differentiation;morpho-histological;somatic embryogenesis
研究领域:
植物生物技术
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植物组织培养
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植物激素
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形态学与组织学
✓ 已验证
DOI
PubMed
高影响因子
Polymer Chemistry
·
2021
·Vol. 12
·期 12
·1806-1815
·
IF 5.582
Li Zhou,Zhenyu Wang,Guangqiang Xu,Chengdong Lv,Qinggang Wang
A highly efficient and controllable ring-opening polymerization of lactones (δ-valerolactone, ε-caprolactone and rac-lactide) has been achieved by using N-heterocyclic olefin (NHO) and thiourea/urea (TU/U) catalytic systems. This catalytic system showed high ring-opening activity and stereoselectivity, delivering biodegradable polyesters with high chain-end fidelity, controlled molecular weights and narrow molar mass dispersities. A detailed investigation of the structure–activity relationship was performed by exploring five NHOs and fourteen TUs/Us. For a fixed NHO, when the acidity of TUs/Us decreases, the polymerization mechanism changes from the (thio)urea anion to the neutral cooperative activation mode, and the catalytic activity first increases and then decreases, displaying a highly effective interval. For a given TU or U, as the basicity of NHOs increases, the catalytic performance improves correspondingly. Besides, highly isoselective ROP of rac-LA (Pm = 0.93) at −78 °C has been also achieved, highlighting the versatility of the NHO/TU(U) system. These findings enrich the type of TU/U and base organocatalyst.
研究领域:
材料科学
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高分子化学
·
有机催化
✓ 已验证
产品关联
DOI
高影响因子
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
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
FOOD CHEMISTRY
·
2020
·
IF 6.306
Kai Zhou,Francesca Patrignani,Yuan-Ming Sun,Rosalba Lanciotti,Zhen-Lin Xu
Ethyl carbamate (EC), a genotoxic and carcinogenic compound in soy sauce accumulated during thermal processes, has raised public health concern for its multipoint potential carcinogenic risk to human. In this work, based on the analysis of EC accumulation during thermal processes of soy sauce, ornithine and quercetin were added before thermal processes to reduce EC accumulation. A reduction rate of 23.7–63.8% in simulated solution was founded. Kinetic studies indicated that ornithine was a byproduct of alcoholysis reaction when EC formed, while quercetin could compete with the precursor ethanol and react with carbamyl compounds, which therefore prevented EC accumulation. A maximum of 47.2% decrease of EC in soy sauce was achieved, and no remarkable changes in volatile compounds profile and color of soy sauce were found. In conclusion, the addition of quercetin and ornithine before thermal processes may be preferable for the controlling of EC content in soy sauce.
研究领域:
食品科学
·
毒理学
·
公共卫生
✓ 已验证
产品关联
DOI
PubMed
高影响因子
EUROPEAN POLYMER JOURNAL
·
2018
·
IF 3.741
Ting Li,Zhining Xie,Jun Xu,Yunxuan Weng,Bao-Hua Guo
In this work, diamine chain extenders containing disulfide bonds are reacted with triisocyanates to yield dynamic chemical cross-links based on exchangeable disulfide bonds. The polyurea system with dynamic bonding shows drastic decline of storage modulus and very short relaxation times above 150 °C so that this polymer exhibits typical dynamic properties, e.g. self-healing, recycling and hysteresis loop recovery. The introduction of disulfide bonds dominates the thermal stimulated dynamic properties, since the control samples without disulfide bonds have longer relaxation times even at high temperatures. Interestingly, presence of disulfide bonds leads to the decline of hydrogen bonding strength which can result in their easier dissociation and subsequently easier topological network rearrangement. In addition, almost complete reversibility of the hydrogen bonding is observed from temperature-dependent Fourier Transform Infrared Spectroscopy, which reveals the important influence of hydrogen bonding on dynamic properties. Thus, Hydrogen bonding dissociation is an indirect reason of dynamic properties, while exchange reaction of disulfide bonds is the primary cause. The results may deepen our understanding of the role of hydrogen bonding in the dynamic materials. In addition, the available commercial raw component, operational feasibility and simplicity constitute a great advantage of the so-prepared dynamic polyurea system, i.e. an effective step to implementation of industrial applications and recycle the nonbiodegradable crosslinked polyureas.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
CHINESE JOURNAL OF POLYMER SCIENCE
·
2019
·Vol. 37
·期 12
·1257-1266
·
IF 2.804
Li Ting,Zheng Tian-Ze,Guo Zhao-Xia,Xu Jun,Guo Bao-Hua
A well-defined quadruple hydrogen bonding strategy involving dimerization of 2-ureido-4[1 H ]-pyrimidone (UPy) units is innovatively designed to prepare polyureas with high overall mechanical properties. Three polyureas containing different amounts of UPy units were synthesized by replacing a portion of isophorone diisocyanate (IPDI) with a UPy-derived diisocyanate. The formation of quadruple hydrogen bonds in hard segments via UPy dimers was confirmed by nuclear magnetic resonance (NMR) and Fourier transform infrared spectroscopy (FTIR). The mechanical properties of the polyureas were evaluated by uniaxial tensile testing. Compared to the polyurea without UPy units, remarkable improvements in Young’s modulus, tensile strength, and toughness were simultaneously achieved when UPy units were incorporated. The mechanism behind the strong strengthening effect rooted in the stronger intermolecular forces among hard segments brought by the quadruple hydrogen bonds, which were stronger than the inherent bidentate and monodentate hydrogen bonds among urea groups, and the slower soft segmental dynamics reaveled by both increased T g and relaxation time of the soft segments. The mechanism behind the strong toughening effect was ascribed to more effective energy dissipation brought by the quadruple hydrogen bonds that served as stronger sacrificial bonds upon deformation. This work may offer new insight into the design of polyurea elastomers with comprehensively improved mechanical properties.
研究领域:
材料科学
·
化学
✓ 已验证
DOI
高影响因子
Materials
·
2020
·Vol. 13
·期 2
·326
·
IF 3.057
Yanxuan Ma,Yingrui Zhang,Jiatong Liu,Yi Sun,Yajie Ge,Xiaoning Yan,Jian Wu
Polyurea microcapsules with Ethylenediamine (EDA) as the core material were synthesized. A set of characterization methods, including optical and scanning electron microscopy (OM and SEM), the Fourier transform infrared (FTIR) spectroscopy and thermogravimetric analysis (TGA) were used to confirm the microcapsule morphology and chemical structures. The influence of emulsifier content and stirring rate on size and morphology of the microcapsules was investigated, and the self-healing performance of EDA-Polyurea microcapsule/epoxy coatings was evaluated by electrochemical impedance spectroscopy (EIS) measurements. The results showed that the microcapsules obtained had good spherical shape with a mean diameter of 0.54–0.70 μm. Compared with pure core material, the microcapsule showed excellent thermostability, and the content of core materials was up to 56.00 wt%. The epoxy coating with 5.0 wt% EDA-Polyurea microcapsules achieved average corrosion resistance efficiencies of 90.00%, significantly enhancing the capability of the scratched coating to resist external corrosion.Keywords:ethylenediamine;polyurea;microcapsules;self-healing;anti-corrosion
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MACROMOLECULES
·
2024
·
IF 5.1
Zhen Yu,Yanlin Liu,Sheng Wang,Yajin Fang,Xiangyu Zhou,Zhaobin Tang,Jin Zhu,Junping Zhang
Dynamic covalent adaptive networks can solve the recycling issue of thermosets. However, dissociative dynamic covalent networks may suffer from instability and network incompleteness at high temperatures or in solvents. Here, we report a novel dynamic covalent bond, N-sulfonyl guanidine urea (SGUA), that can undergo catalyst-free metathesis reactions, in which a passivation strategy of increasing the dissociation temperature of guanidine urea by introducing electron-withdrawing N-sulfonyl groups into adjacent positions was developed. Unlike conventional dissociative dynamic urea bonds, SGUAs exhibit associative metathesis reactions at around 120–180 °C, with a high dissociation threshold of 180 °C. The dynamic covalent polyurea constructed by SGUAs, named PSGUAs, exhibits ultrastrong (Young’s modulus exceeding 4 GPa and tensile strength exceeding 60 MPa) and stable (thermal stability, network structure integrity under reprocessing, and dimensional stability) performances. Furthermore, due to the excellent dynamic characteristics of SGUAs, PSGUAs were successfully reprocessed after 30–60 min of hot pressing at 160 °C and 20 MPa. Combining the long-lasting antibacterial properties of PSGUAs with long-term use, this study marks a substantial improvement in the field of dynamic polymer networks, giving a solution for balancing material stability, high performance, and reprocessability.
研究领域:
材料科学
·
聚合物化学
·
可持续材料
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Polymer Materials
·
2025
·
IF 4.7
Wenzhe Niu,Yutao Yang,Zhangyan Shi,Yuedong Xing,Jianben Xu,Xiang Xu,Faai Zhang
With global ozone layer depletion, developing sustainable ultraviolet (UV)-shielding materials with high environmental persistence has emerged as a critical challenge. Conventional UV-shielding agents face limitations in biodegradability and durability. In contrast, rosin, a natural biomass featuring hydrogenated phenanthrene rings and π-conjugated systems, exhibits exceptional UV absorption (200–400 nm). In this study, we synergistically integrated dynamic hindered urea bonds (HUBs) with rosin-derived motifs to construct multifunctional rosin-based poly(urethane-urea) networks. Four diisocyanate-derived prepolymers were synthesized and subsequently copolymerized with rosin derivatives via UV curing. The isocyanate architectures were found to govern hydrogen-bonding density, mechanical adaptability (tensile strength: 3.9–16.4 MPa; toughness: 8–19.9 MJ·m–3), and self-healing performance (88.6% within 24 h at 60 °C). The optimized material achieved 95% UV-A and 100% UV-B shielding efficiencies while maintaining chemical stability (acid, alkali, and high temperature environments). Reversible HUBs further enable recyclability and programmable shape-memory behavior. These features highlight the material’s potential for advanced applications such as smart protective coatings and flexible electronic encapsulation.
研究领域:
高分子科学
·
材料科学
·
环境科学
·
化学工程
·
有机化学
·
应用化学
✓ 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）