Polymer Chemistry
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2014
·Vol. 5
·期 8
·3098-3106
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IF 5.368
Yu Jin,Yufeng Ji,Xiaojiang He,Suli Kan,Haidong Xia,Binqi Liang,Jia Chen,Hao Wu,Kai Guo,Zhenjiang Li
o-Benzenedisulfonimide (OBS) was demonstrated for the first time to be a safe, recyclable, and water-tolerant Brønsted acidic catalyst for the ring-opening polymerization (ROP) of δ-valerolactone and ε-caprolactone using benzyl alcohol as the initiator. The polymerizations proceeded to afford poly(δ-valerolactone) and poly(ε-caprolactone) with controlled molecular weights and narrow polydispersities. The kinetics and chain extension experiments were carried out to confirm the controlled/living fashion of the polymerizations. In addition, 1H NMR and MALDI-TOF MS measurements strongly indicated that the initiator residue was incorporated into the obtained polymers. Furthermore, well-defined poly(δ-valerolactone)-block-poly(ε-caprolactone) has been successfully synthesized via OBS-catalyzed ROP.
研究领域:
高分子化学
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材料科学
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DOI
高影响因子
POLYMER TESTING
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2020
·
IF 3.275
Lidong Feng,Sheng Xiang,Yanlong Liu,Xinchao Bian,Gao Li,Xuesi Chen
An analytical method was developed to quantitatively determine residual monomers, namely, lactide (LA) and ε -caprolactone (CL), in poly(lactide- co - ε -caprolactone) (PLCL) using an internal-standard method of gas chromatography (GC). PLCL and diphenyl ether (DPE) as an internal standard were initially dissolved in dichloromethane (DCM), and then PLCL was precipitated in cyclohexane. The residual LA and CL monomers in PLCL, as well as DPE, were extracted into cyclohexane from the polymer solution. The resulting solution was directly injected into a GC system. This method was practical for measuring the residual LA and CL contents in PLCL. The relative standard deviation ( RSD ) ( n = 5) denoting the repeatability of this method was less than 5.6% and 4.3% for the LA and CL measurements, respectively, indicating that the method was sufficiently precise. The recovery rate of standard addition was 96.5%–101.5% and 98.4%–104.2% for the determination of LA and CL in PLCL, respectively. The RSD of the recovery of standard addition ( n = 5) was not more than 2.0%, indicating that the method was sufficiently accurate.
研究领域:
分析化学
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高分子材料科学
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医学材料
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产品关联
DOI
高影响因子
ChemistrySelect
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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
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有机催化
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产品关联
DOI
高影响因子
EUROPEAN POLYMER JOURNAL
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2018
·
IF 3.741
Songquan Xu,Hui Zhu,Zhenjiang Li,Fulan Wei,Yu Gao,Jiaxi Xu,Haixin Wang,Jingjing Liu,Tianfo Guo,Kai Guo
H-bond donor (HBD) and base co-catalysis achieved great success in ring-opening polymerization (ROP). Parallel H-bond donor and Brønsted acid (HBD–BA) cocatalysis has been scarcely explored in ROPs. In developing the HBD–BA catalysis in to versatile toolbox for ring-opening polymerizations of wider scope and better control, tunable HBDs including boronate pinacol ester urea (BU), urea (U), and thiourea (TU) were evaluated in cooperation with trifluoroacetic acid (TFA) in HBD–BA catalytic mode. Each of the HBD–TFA co-catalyst promoted ROPs of δ-valerolactone (VL) and ε-caprolactone (CL) successfully. The catalytic performances of the HBD–TFA on the HBD part was in an order of BU > U > TU to their corresponding ROPs of VL and CL. The turnover frequencies of the catalyzed ROPs of VL and CL by BU–TFA was twice as that of TFA. The ROPs afforded homopolymers with predicted molecular weights (PVL, M n,NMR = 2.51–9.92 kg mol −1 ; PCL, M n,NMR = 2.51–11.1 kg mol −1 ) and narrow dispersities (PVL, Đ ≤ 1.16; PCL, Đ ≤ 1.18) by ratios of monomer to initiator from 20 to 100. The obtained polymers were analyzed by 1 H NMR, 13 C NMR, and MALDI-ToF MS, the results indicated the high chain-end fidelity. Chain extension experiments were conducted by a first ROP of VL/CL and second ROP of CL/VL with precise molecular weights (from 2.98 kg mol −1 to 6.15 kg mol −1 ) and narrow dispersities below 1.18. The kinetics plots showed a distinct first order relationship between ln([VL] 0 /[VL]) versus the reaction time, it indicated the controlled nature of the catalytic ROP. NMR titrations supported the proposed mechanism that HBD associated with TFA and promoted the cationic polymerization.
研究领域:
高分子化学
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催化化学
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DOI
高影响因子
POLYMER
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2015
·
IF 3.562
Yingying Ren,Zhiyong Wei,Xuefei Leng,Yurong Wang,Yang Li
Boric acid ( 1 , B(OH) 3 ) was investigated as metal-free biocatalyst for its activity towards the bulk ring-opening polymerization (ROP) of ε -caprolactone (CL) initiated by benzyl alcohol (BnOH). Moreover, other boric acid derivates such as phenylboronic acid ( 2 ), 2-thienylboronic acid ( 3 ), 2-furanylboronic acid ( 4 ) and 5-pyrimidinylboronic acid ( 5 ) were also used as acidic catalysts to synthesize poly( ε -caprolactone) (PCL), poly( δ -valerolactone) (PVL) and poly(trimethylene carbonate) (PTMC). The studies on the polymerization kinetics for all catalysts confirm that the reaction rates are first-order with respect to monomer and their catalytic activities follow the order 1 > 3 > 2 ≈ 4 > 5 . Furthermore, the block copolymerization of ε -caprolactone (CL) with δ -valerolactone (VL) and trimethylene carbonate (TMC) successfully proceeded by the sequential monomer addition to give PCL- b -PVL and PTMC- b -PCL copolymers , indicating the living nature of the present polymerization system. The end group analysis by 1 H NMR and MALDI-TOF MS measurements suggested that the benzyl moiety of initiator inserted into the synthesized polymeric chain. The existence of the interaction between the catalyst B(OH) 3 and the monomer CL supports that B(OH) 3 catalyzed ROP of CL preferred an activated monomer mechanism. A possible model for the initiation and propagation procedures of ROP of cyclic esters catalyzed by boric acid in the presence of benzyl alcohol was proposed.
研究领域:
材料科学
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催化化学
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高分子化学
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产品关联
DOI
高影响因子
Bioresources and Bioprocessing
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2021
·Vol. 8
·期 1
·1-9
·
IF 4.578
Zhang Xiaowang,Tan Zhuotao,Li Chaojian,Qi Siyu,Xu Mengjiao,Li Ming,Xiong Wenlong,Zhuang Wei,Liu Dong,Zhu Chenjie,Ying Hanjie
Background Lactones are important compounds in the field of medicine, material and chemical industry. One of the promising accesses to these flexible scaffolds is NAD(P) + -dependent alcohol dehydrogenases-catalyzed oxidative lactonization of diols, which relies on the construction of an efficient NAD(P) + regeneration system. Results In this study, a novel system combining horse liver alcohol dehydrogenase (HLADH) with the synthetic bridged flavin cofactor was established for biosynthesis of lactones. The reaction conditions of this system were optimized and a variety of lactones including chiral lactones were efficiently obtained from various diols. Compared to the previously reported NAD(P) + -regeneration systems, this system showed better regeneration efficiency and product yield. A two-phase system was further applied to solve the problem of product inhibition, and 80% yield was obtained at the condition of 300 mM substrate. Conclusions This study provides an efficient method to synthesis of lactones from diols under mild conditions. We believe this system will be a promising alternative to promote the synthesis of other valuable compounds. Graphic abstract
研究领域:
生物催化
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化学生物学
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有机化学
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药物化学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF POLYMER RESEARCH
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2023
·Vol. 31
·期 1
·1-9
·
IF 2.8
Wu Hai-Bo,Zhou Xian-Tai,Zhou Xiao-Wu,Fang Yan-Xiong
As a biodegradable polyester, the commercialized synthesis protocol of poly(ε-caprolactone) (PCL) under mild conditions is of great significance and attractive. Herein, the ring-opening polymerization (ROP) of ε-caprolactone (ε-CL) using FeCl 3 catalyst and benzyl alcohol (BnOH) as the initiator was developed. FeCl 3 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 98.8% at 60 °C within 4 h, with number-average molecular weight ( M n) and dispersity (PDI) of 1.65 × 10 4 g/mol and 1.28, respectively. Moreover, a coordination-insertion ring-opening polymerization mechanism mediated by FeCl 3 was proposed. Overall, this work is expected to provide a feasible industrial method for the preparation of PCL from the direct aerobic oxidation of cyclohexanone.
研究领域:
材料科学
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化学工程
✓ 已验证
DOI
高影响因子
POLYMER
·
2016
·
IF 3.586
Qilei Song,Yening Xia,Shuangyan Hu,Junpeng Zhao,Guangzhao Zhang
The copolymerization of ε -caprolactone (CL) with its structural isomer , δ -hexalactone (HL), or trimethylene carbonate (TMC) catalysed by diphenyl phosphate was investigated. Copolymers with molar fraction of CL units ranging from 54% to 95% were obtained. Molecular characterization exhibited random distribution of the two monomeric units (CL/HL or CL/TMC), owing to the extensive occurrence of transesterification scrambling reactions at high temperature. Compared with poly( ε -caprolactone) (PCL), the copolymers showed reduced crystallinity and enhanced enzymatic degradability as revealed by the analysis with differential scanning calorimetry and quartz crystal microbalance with dissipation, respectively. Interestingly, the incorporation of HL units showed a more profound impact than TMC. It is therefore considered that organocatalytic copolymerization with HL, a bio-renewable lactone, can serve as an effective method to regulate the properties of PCL.
研究领域:
材料科学
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生物医学工程
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产品关联
DOI
高影响因子
Current Pharmaceutical Analysis
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2020
·Vol. 16
·期 6
·763-773
·
IF 0.923
Yaro Peter,Nie Jing,Xu Mingcheng,Zeng Kui,Zeng Su
Background: Terpene lactones are major components of ginkgo biloba extract which are used in cardiovascular and degenerative diseases. To study the involvement of transporters in the transport/disposition of ginkgolides A, B, C, and bilobalide, a bioanalytical assay was developed by
LCMS/ MS system for the quantitation of intracellular levels of terpene lactones in cells expressing organic cation transporter 2 (OCT2). Methods: The assay involved an optimized simple sample handling with methyl tert-butyl ether for liquid-liquid extraction and reconstitution in modified
dissolution solution. Pretreatment of samples with 50 μM ascorbic acid and the addition of ascorbic acid and formic acid in dissolution solution significantly reduced matrix effect and stabilized the postpreparative samples. Separations were performed by Zobrax RRHD column (extend-C18 1.8μm,
3.0 x 100mm) and acetonitrile gradient elution. The analysis was carried out in the negative ion scan mode using multiple reaction monitoring. Results: The method was validated for linearity (concentration range of 20-5000nM), accuracy (±13.1%), precision (<11.0%), recovery
(94.31–105.9%), matrix effect (93.8-111.0%) and stability. Finally, the method was applied in the determination of intracellular concentrations of ginkgolides A, B, C, and bilobalide in Madin-Darby canine kidney (MDCK-mock) and MDCK-OCT2 cells in uptake study. Conclusion: The developed
method was successfully validated. Results suggest that OCT2 is involved in the renal disposition of ginkgolide A, B, and bilobalide. This method would foster the study of transport mediated activity via the interaction of ginkgolides and bilobalide with cellular systems.
研究领域:
药理学
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分析化学
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药物代谢
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DOI
高影响因子
JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY
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2014
·Vol. 52
·期 8
·1185-1192
·
IF 3.245
Jinbao Xu,Junzhe Song,Stergios Pispas,Guangzhao Zhang
Ring-opening polymerization (ROP) of ε -caprolactone (CL) using salicylic acid (SAA) as the organocatalyst and benzyl alcohol as the initiator in bulk at 80 °C successfully proceeded to give a narrowly distributed poly( ε -caprolactone) (PCL). In addition, 2-hydroxyethyl methacrylate, propargyl alcohol, 6-azido-1-hexanol, and methoxy poly(ethylene glycol) were also used as functional initiators. The 1 H NMR, SEC, and MALDI-TOF MS measurements of the PCL clearly indicate the presence of the initiator residue at the chain end, implying that the SAA-catalyzed ROP of CL was through the activated monomer mechanism. The kinetic experiments confirmed the controlled/living nature of the SAA-catalyzed ROP of CL. Furthermore, the block copolymerization of CL and δ -valerolactone successfully proceeded to give poly( ε -caprolactone)- block -poly( δ -valerolactone). © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52 , 1185–1192
研究领域:
高分子化学
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材料科学
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DOI
高影响因子
International Journal of Polymer Science
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2018
·
IF 1.718
Ruijiang Li,Peng Wang,Haohao Ren,Hong Li,Zhengwen Ding,Yonggang Yan
Poly(delta-gluconolactone) (PGL) and poly(delta-gluconolactone--caprolactone) (P(GL-CL)) were synthesized through ring-opening polymerization (ROP) and characterized by FT-IR, NMR, XRD, intrinsic viscosity, GPC, DSC, and TGA. The crystallinity of P(GL-CL) with various d-GL/CL ratios (d-GL/CL = 5 : 5, 4 : 6, 3 : 7, 2 : 8, and 1 : 9) was 12.09 to 59.78% while PGL was amorphous. Melting temperature () of these polymers was 49.8 to 62.0°C and decomposition temperature was 282 to 489°C depending on the d-GL/CL ratios. In addition, all these polymers were degradable and the degradation rates could be controlled by adjusting d-GL/CL ratios. These results indicated that PGL and P(GL-CL) might be promising novel absorbable materials.
研究领域:
材料科学
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生物医学工程
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产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2022
·
IF 5.518
Nehala Shahnawaz,Tauqir A. Sherazi,Rongqiang Li,Fengting Hao,Fengmei Yan,Youwei Liu
Using the potential of compartmenting free enzyme in dispersion phase of Pickering emulsion , a simple continuous flow system for free enzyme catalytic cycle-opening polymerization of ε-caprolactone has been studied. In order to generate suitable and stable Pickering emulsions, silica nanoparticles(SiNPs) modified with octyltrimethoxysilane (OTMS) and aminopropyltrimethoxysilane (APTMS) are synthesized, and the modification is confirmed by Fourier transformed infrared (FTIR) spectroscopy and water contact angle (CA). It is found that CA values of modified SiNPs increased from 107° to 168° with the increase of ratio of OTMS to APTMS from 1:1 to 8:1, which indicates that wettability of SiNPs has been changed from original hydrophilic to hydrophobic and consequent has an effect on the properties of Pickering emulsions. Among the modified SiNPs, the silica modified with OTMS: APTM (2:1) can construct stable W(water)/O(toluene) Pickering emulsion , confirmed by images from confocal laser microscope. The stable Pickering emulsion comprising of Candida Antarctica lipase B dispersed in water droplets is selected as a model for investigation of conditions for ring-opening polymerization of ε-caprolactone. The high monomer conversion is achieved with amount of emulsifier and enzyme being used 5 wt% and 3 wt%, respectively, and flow rate 3 mL h −1 in continuous flow process , which is higher than that in batch reaction system although the formula of Pickering emulsion is identical. Specially, the polycaprolactone (PCL) with an average molecular weight of 210151 g/mol, as per gel permeation chromatography (GPC) analysis, is achieved. The catalytic efficiency of enzyme for polymerization is not changed even after several cycles of use. The present enzyme immobilization within Pickering emulsion offers a green and prospective approach for synthesis of high molecular weight polymer in continuous flow process .
研究领域:
生物化学
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材料科学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）