RUSSIAN JOURNAL OF GENERAL CHEMISTRY
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2017
·Vol. 87
·期 11
·2643-2647
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IF 0.553
Liang G.-P.,Guo J.-H.,Jiang R.-W.
Istaroxime 1 , a novel cardiotonic agent with high efficiency and low toxicity was synthesized from dehydroepiandrosterone 2 using a novel approach that included epoxidation, ring-opening, substitution, and oximation. The new protocol without gas protection was milder than the reported approaches. The overall yield of the method was 24.1%.
研究领域:
药物化学
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有机合成
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2017
·
IF 4.339
Zhixiong Luo,Somboon Chaemchuen,Kui Zhou,Andres Alvarado Gonzalez,Francis Verpoort
A series of metal organic frameworks (MOFs) MDABCO (M = Co, Ni, Cu, Zn; DABCO = 1,4-diazabicyclo[2.2.2]octane) are utilized as catalysts for the bulk ring-opening polymerization of l -lactide. The catalytic activity varies in the order CuDABCO, NiDABCO < ZnDABCO, CoDABCO. By adding lactic acid, we unexpectedly observed enhanced catalytic activity. The combined use of lactic acid and ZnDABCO during polymerization results in a highly active polymerization system, along with the gradual change of MOFs structure caused by an increased acid concentration. Compared to related homogeneous fragments, such as zinc nitrate and 1,4-diazabicyclo[2.2.2]octane, ZnDABCO is found to afford highly isotactic polylactide, which would be ascribed to the unique structural properties of MOFs.
研究领域:
材料科学
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高分子化学
✓ 已验证
DOI
高影响因子
Biomimetics
·
2022
·Vol. 7
·期 2
·50
·
IF 3.743
Xutao Ma,Xiaohui Fu,Jing Sun
As awareness of environmental protection increases, environmentally friendly coatings have been receiving great interest. Zwitterionic polymers are considered promising candidates due to their biocompatibility and excellent antifouling properties. In this paper, a type of polypeptoid containing zwitterions on the side chain was synthesized via ring-opening polymerization (ROP) and post-modification. This obtained polypeptoid was subsequently grafted onto the surface of polydimethylsiloxane (PDMS) via plasma and UV-induced surface polymerization. Surface morphology and protein adsorption tests of the resulting coating were systematically carried out. The results show that the modified coating has excellent antifouling properties and thus has great potential for environmentally friendly coating applications.Keywords:zwitterionic polymers;antifouling coatings;ring-opening polymerization
研究领域:
材料科学
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环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
EUROPEAN POLYMER JOURNAL
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2022
·
IF 5.546
Xianqiang Zeng,Liguo Wang,Yan Cao,Chen Liu,Ziqiang Han,Peng He,Huiquan Li
Aliphatic polyethers are synthesized byring-opening polymerization (ROP) of the most common epoxide monomers, such as ethylene oxide (EO) and propylene oxide (PO). 1,2-Butylene oxide (BO) and tetrahydrofuran (THF) are potentially extended ROP monomers, which can give polyether unique properties. In this work, a series of poly(1,2-butylene oxide- stat -tetrahydrofuran)s (PBO- stat -PTHFs) with M n of 900–3700 g·mol −1 were synthesized by cationic ring-opening polymerization (CROP) of BO with THF using strong Lewis acid Rare Earth triflates (RE(OTf) 3 ) as catalysts and diols as an initiator at room temperature. PBO- stat -PTHFs product with yield up to 90 %, narrow polydispersity of Đ <1.30, and molar ratio of PBO to PTHF 1:1 were obtained. The copolymerization process was studied by in-situ IR and 1 H NMR spectroscopy analysis, and the results showed that PBO- stat -PTHF is a statistical copolymer. The early stage of the polymerization reaction was dominated by the activated chain end mechanism (ACEM), which incorporates a large amount of THF into the polymer chains. However, the late stage of the polymerization reaction was dominated by the activated monomer mechanism (AMM), which incorporates a large amount of BO into the polymer chains. Most PBO- stat -PTHFs have a suitable M n range, super high viscosity index (≥198) and low pour point (≤-53 °C), which can be used as a lubricant base oil and additives. In addition, PBO- stat -PTHFs have excellent miscibility with polyalphaolefin (PAO), which could significantly improve the PAO viscosity index. This study provides a mild route to construct high-performance copolyether materials through cationic ring-opening controllable polymerization.
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
MACROMOLECULES
·
2023
·
IF 5.5
Nan Li,Shengfu Yang,Kan Zhang
The future development of benzoxazine thermosetting resins as advanced polymeric materials depends on designing more attractive chemical structures and reaching a deeper understanding of the structure–property relationship at the molecular level. Herein, we synthesized a new series of benzoxazines containing the thiophenecarboxamide or thiopheneacetamide functionality at the ortho- and para-positions with respect to oxygen in the oxazine ring. Successful syntheses of thiophene-rich benzoxazine monomers and their corresponding molecular characterizations were confirmed by Fourier transform infrared (FT-IR) spectroscopy, nuclear magnetic resonance (NMR), and high-resolution mass spectroscopy. Ring-opening polymerization processes of benzoxazines and thermal properties of their resulting polybenzoxazines were studied by differential scanning calorimetry, in situ FT-IR spectroscopy, and thermogravimetric analysis. In addition, a combined experimental and computational study using both 1D and 2D NMR as well as density functional theory calculations provided kinetic insights into the effects of structural and hydrogen bonding on the polymerization mechanism. With the designed varieties of hydrogen bonds in these novel benzoxazines, it has been found that oxygen in the oxazine ring involved in stronger hydrogen bonding can generate a relatively weaker O–CH2 bond, leading to the reduced ring-opening polymerization temperature. The fundamental investigations presented in the current work provide us a deeper understanding of the hydrogen bonding interaction in benzoxazine as well as its role in polymerization behavior. Moreover, these newly obtained thiophene-rich benzoxazines also give us ample opportunities to develop high-performance polybenzoxazine thermosets with promising applications.
研究领域:
材料化学
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高分子科学
✓ 已验证
产品关联
DOI
高影响因子
ORGANOMETALLICS
·
2019
·
IF 4.1
Chuanzhi Wei,Binghao Han,Dejuan Zheng,Quande Zheng,Shaofeng Liu,Zhibo Li
The aluminum complexes LAlMe2 (Al1–Al5: LH = 2,6-(R1)2-4-R2-C6H2NHCH2C6H4-2-PPh2; Al1, R1 = H, R2 = H; Al2, R1 = Me, R2 = H; Al3, R1 = iPr, R2 = H; Al4, R1 = Ph2CH, R2 = iPr; Al5, R1 = Cl, R2 = H) have been synthesized and characterized by elemental analysis and 1H, 13C, and 31P NMR. NMR analysis in solution reveals an interesting hemilabile coordination of the soft P donor. The molecular structures of Al2–Al4 were defined by X-ray diffraction studies, showing a distorted-tetrahedral geometry around the aluminum center in all structures. Careful comparison of these crystal structures suggested that different substituents on the ligands could lead to unignorable changed coordination environments around the Al center, thus affecting their catalytic properties. In the presence of BnOH, complexes Al1–Al5 efficiently catalyzed the ring-opening polymerization (ROP) of ε-caprolactone (ε-CL) with high conversions in a controlled manner, and high molecular weights (Mn up to 118.6 kg mol–1) of polycaprolactones (PCLs) were readily prepared. Immortal polymerizations by Al4 having bulky Ph2CH groups were also studied with up to 20 equiv of alcohols and 2000 equiv of monomers, without sacrificing polymerization control.
研究领域:
化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
Polymers
·
2017
·Vol. 9
·期 3
·83
·
IF 3.364
Shaofeng Liu,Jie Zhang,Weiwei Zuo,Wenjuan Zhang,Wen-Hua Sun,Hongqi Ye,Zhibo Li
The stoichiometric reactions of 8-(2,6-R1-4-R2-anilide)-5,6,7-trihydroquinoline (LH) with AlR3(R = Me or Et) afforded the aluminum complexesLAlR2(Al1–Al5,Al1: R1=iPr, R2= H, R = Me;Al2: R1= Me, R2= H, R = Me;Al3: R1= H, R2= H, R = Me;Al4: R1= Me, R2= Me, R = Me;Al5: R1= Me, R2= Me, R = Et) in high yields. All aluminum complexes were characterized by NMR spectroscopy and elemental analysis. The molecular structures of complexesAl4andAl5were determined by single-crystal X-ray diffractions and revealed a distorted tetrahedral geometry at aluminum. In the presence of BnOH, complexesAl1–Al5efficiently initiated the ring-opening homopolymerization ofε-caprolactone (ε-CL) andrac-lactide (rac-LA), respectively, in a living/controlled manner.Keywords:aluminum complexes;crystal structures;ring-opening polymerization;biodegradable polyesters
研究领域:
化学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of the American Chemical Society
·
2019
·
IF 14.695
Cheng-Jian Zhang,Tian-Cheng Zhu,Xiao-Han Cao,Xin Hong,Xing-Hong Zhang
The synthesis of poly(thioether), a highly desired sulfur-containing polymer, is still a key challenge. Herein, we report a simple and facile approach to poly(thioether)s by closed-system one-pot reaction of carbonyl sulfide (COS) and epoxides. This route underwent the coupling reaction of COS with epoxides, followed by decarboxylative ring-opening polymerization (ROP) of the generated mixed cyclic thiocarbonates with releasing of CO2 and a little bit of COS. Organic base was used as catalyst and initiator in the two steps, respectively. The oxygen/sulfur exchange reaction was driven by successive regioselective elementary reactions and spontaneous releasing of CO2 (COS), leading to the sulfur atom of COS transferring to poly(thioether)s, which was well demonstrated by DFT studies. This work provides an easy-to-handle, metal-free route to poly(thioether)s bearing diverse structures by using readily available chemicals.
研究领域:
高分子化学
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材料科学
✓ 已验证
DOI
PubMed
高影响因子
POLYMER BULLETIN
·
2014
·Vol. 71
·期 6
·1331-1347
·
IF 1.491
Yuan Mingwei,He Zhengguo,Li Hongli,Jiang Lin,Yuan Minglong
Ring-opening polymerization of l -lactic acid O -carboxyanhydride was catalyzed by 4-dimethylaminopyridine in the presence of polyols pentaerythritol (PER) or dipentaerythritol (DPE). A high yield and relatively high molecular weight of 4- or 6-arm star PLA were obtained. The reaction was observed to be conducted easily and controllably. NMR analysis revealed that the end of the star PLA chain is a hydroxyl group and the central core is a PER or DPE group. The crystallinity of star PLA is lower than that of linear PLA. The crystallinity of 4-arm star PLA is lower than that of 6-arm PLA. Compared with that of 4-arm star PLA, the molecular arrangement of 6-arm star PLA may be relatively more regular.
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
ChemistrySelect
·
2023
·Vol. 8
·期 34
·e202301948
·
IF 2.1
Hai-Bo Wu,Xian-Tai Zhou,Xiao-Wu Zhou,Yan-Xiong Fang
Graphical Benzoic acid has been proved to be an efficient catalyst for the ring-opening polymerization of ϵ-caprolactone under mild conditions. A monomer-activated ring-opening polymerization mechanism mediated by benzoic acid was proposed. It is expected to realize the one-step preparing of poly (ϵ-caprolactone) through the direct aerobic oxidation of cyclohexanone. The development of a feasible industrial method for poly(ϵ-caprolactone) (PCL) preparation is great of significant and challenging. The bulk ring-opening polymerization of ϵ-caprolactone (ϵ-CL) using various organic acid catalysts and benzyl alcohol (BnOH) as the initiator was developed. Benzoic acid (BA) has been proved to be an efficient catalyst for the ROP of ϵ-CL under mild conditions. The conversion of ϵ-CL to PCL was 84.7 % under the optimized reaction conditions, with number-average molecular weight ( M n ) and dispersity (PDI) of 7700 g/mol and 1.25, respectively. Moreover, a monomer-activated ring-opening polymerization mechanism mediated by benzoic acid was proposed. Overall, this work is expected to provide a feasible industrial method for the preparation of PCL using benzoic acid as organocatalyst.
研究领域:
高分子化学
·
有机催化
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Nano Materials
·
2021
·
IF 5.097
Haojie Zhao,Beili Yi,Xiaomeng Si,Lei Cao,Longxing Su,Yanli Wang,Lien-Yang Chou,Jin Xie
Perfect crystals do not exist; however, the introduction of defects can tailor the physical and chemical properties of materials. Defects in metal–organic frameworks (MOFs) have been demonstrated to be important in many applications, including but not limited to catalysis, gas separation, and energy storage. While a few liquid-phase synthesis methods have been reported to prepare defect-rich UiO-66, the heavy use of organic solvents may cause irreversible environmental problems. Here, we present a green, rapid, and facile solid-state synthesis approach to prepare UiO-66. All UiO-66 crystals remain in the nanometer size due to the limited diffusivity of growth species in solid-state synthesis without a large quantity of the solvent. The defect concentrations can be fine-tuned by the content of ethanol addition. Defect-rich UiO-66 shows excellent catalytic activity to the ring opening of epoxides with alcohols. This work provides insights into the large-scale production of defect-rich MOFs.
研究领域:
材料科学
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催化化学
·
环境科学
✓ 已验证
DOI
高影响因子
EUROPEAN POLYMER JOURNAL
·
2024
·
IF 5.8
Zedong He,Hao Zhang,Ju Xie,Ti Zhou,Jie Zhang
Silicon-containing polyesters represent a novel class of polymers that integrate silicone and polyester units within their main chain. Polysiloxanes typically consist of flexible chain segments, while polyesters are characterized by their rigidity. The combination of these two components in the main chain offers the potential for tunable properties across a broad range. For the first time, a new organosilicon cyclic ester monomer (Si-Mon) was synthesized using a pseudo-high dilution condensation method. Both theoretical and experimental studies confirm that the ring-opening reaction site of Si-Mon is the ester group, rather than the Si-O-Si bond. Silicon-containing polyesters (SiPET-Series 1) with molecular weights exceeding 20,000 Da were efficiently and rapidly synthesized at room temperature, utilizing benzyl alcohol as the initiator and t-BuP 4 as the catalyst. Organosilicon polyester diols (SiPET-Series 2) with varying molecular weights were produced using 1,4-benzenedimethanol as the initiator. Additionally, a new type of organosilicon polyester elastomer (SiPET-E) was developed by employing SiPET-Series 2 as the base gum and (2,4,6-trioxotriazine-1,3,5(2H,4H,6H)- triyl)tris(hexamethylene)isocyanate (THDI) as the crosslinking agent. The stress–strain behavior of SiPET-E is influenced by the molecular weight of SiPET-Series 2. Notably, SiPET-E exhibits remarkable properties; for instance, it demonstrates superelastic characteristics when the molecular weight of SiPET-Series 2 is 13,000 g/mol, achieving a tensile strength of 2.56 MPa and an elongation at break of 776 % without the use of reinforcing fillers.
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）