生物可降解电活性苯胺聚合物

导电聚合物通过其独特的电活性或导电性,可智能地传递或控制细胞电化学信号,从而定向诱导组织器官的再生修复,已成为神经和组织工程领域研究的热点.本文主要介绍了我们实验室生物可降解电活性苯胺聚合物的相关工作,介绍了以苯胺齐聚物与可降解高分子接枝或嵌段制备具有电活性、可生物降解的新型导电聚合物及其在细胞培养和组织工程方面的研究.介绍了静电纺丝制备电活性纳米纤维的概况.苯胺齐聚物与可降解聚合物的接枝和嵌段可同时赋予其电活性、生物相容性和生物可降解性.可生物降解的电活性聚合物是未来生物组织工程领域的发展趋势之一,具有广阔的应用前景.     

原位红外光谱法研究对氯苯酚在Pt电极上的电氧化行为

采用原位红外光谱法研究了碱性条件下对氯苯酚(PCP)在Pt电极上电化学氧化的脱氯反应机理. 研究结果表明Pt电极对PCP有良好的电化学反应活性, 其氧化过程首先是对氯苯酚负离子氧化生成对氯苯氧自由基, 该自由基可与对氯苯酚负离子作用生成芳香醚低聚物; 随着电位升高, 对氯苯酚负离子经电化学氧化生成了苯二酚盐(还可能存在其氧化产物不饱和羧酸盐); 当电位继续升高, 苯二酚盐进一步氧化形成苯醌; 最后, 在Pt表面生成小分子羧酸盐, 同时生成了最终产物CO2. 但由于芳香醚低聚物等不溶性聚合物膜的形成并吸附在Pt电极表面, 可造成Pt电极毒化, 使得Pt电极在使用过程中逐渐失去活性.     

微盘电极应用-聚在乙二醇离子导体中的伏安分析

在聚乙二醇离子导体中, 研究了二茂铁在其中的伏安性质, 结果表明如果电活性物质与聚合物溶剂不发生相互反应, 那么电活性物质在聚合物溶剂中的扩散仍然遵循Fick扩散方程, 其伏安结果可以定量描述。提出了在聚合物离子导体中不需要知道电活性物质的摩尔浓度就可估算扩散系数的伏安方法, 探索了在聚合物离子导体中电活性物质的扩散规律。     

微盘电极应用-聚在乙二醇离子导体中的伏安分析

在聚乙二醇离子导体中, 研究了二茂铁在其中的伏安性质, 结果表明如果电活性物质与聚合物溶剂不发生相互反应, 那么电活性物质在聚合物溶剂中的扩散仍然遵循Fick扩散方程, 其伏安结果可以定量描述。提出了在聚合物离子导体中不需要知道电活性物质的摩尔浓度就可估算扩散系数的伏安方法, 探索了在聚合物离子导体中电活性物质的扩散规律。     

聚电解质中电活性物质氧化还原反应机理的现场显微红外光谱电化学研究

用现场显微红外光谱电化学方法研究了几种电活性物质,包括无机盐、有机物、无机聚合物微粒在聚电解质中的氧化还原反应及其机理。     

可溶性聚3-[(二茂铁甲酸乙酯)三乙氧基]氧基噻吩的合成与性质表征

采用化学聚合方法合成了一种含二茂铁电活性基团的新型导电聚噻吩衍生物聚3-[(二茂铁甲酸乙酯)三乙氧基]氧基噻吩, 用1H NMR和红外光谱等方法对其结构进行了表征. 实验结果表明, 该聚合物可溶于三氯甲烷、四氢呋喃和丙酮等有机溶剂, 并且二茂铁在聚合物中依然保持良好的氧化还原活性, 对钠离子具有良好的选择性络合作用.     

微盘电极应用在乙二醇离子导体中的伏安分析

在聚乙二醇离子导体中,研究了二茂铁在其中的伏安性质,结果表明如果电活性物质与聚合物溶剂不发生相互反应,那么电活性物质在聚合物溶剂中的扩散仍然遵循Fick扩散方程,其伏安结果可以定量描述.提出了在聚合物离子导体中不需要知道电活性物质的摩尔浓度就可估算扩散系数的伏安方法,探索了在聚合物离子导体中电活性物质的扩散规律.     

电活性超支化聚合物的合成与性质

通过分子设计, 利用A2+B3反应合成了一种新型电活性超支化聚合物材料. 该材料在保持聚苯胺的电活性基础上, 还具有超支化聚合物特有的低黏度(其特性黏度为0.33 dL/g)、低结晶性及良好的溶解性. 利用紫外-可见光谱对聚合物的氧化过程进行了监测. 热失重分析显示, 该材料具有较好的热稳定性, 失重10%时的温度高达517 ℃. 该材料具有较高的介电常数, 有望成为一种具有实际应用价值的高介电材料.     

Schiff碱基过渡金属镍络合物的电化学聚合:阳极电聚合中扫描速率的影响(英文)

采用线性电位扫描法制备了水杨醛-Schiff碱基过渡金属镍络合物的聚合物poly[Ni(salen)],扫描速率为5-150 mV.s-1.采用场发射显微镜观察了聚合物poly[Ni(salen)]的表面形貌.研究了电聚合中扫描速率对聚合物生长的影响,电聚合速率(dГ/dm)与扫描速率(v)呈指数衰退关系,通过库仑电量分析指出电聚合扫描速率在20mV.s-1时聚合产物中含有最多的氧化还原活性点.扫描速率提高时单体的扩散步骤限制了聚合物的生长,所以氧化还原活性点总量随着扫描速率的提高而开始下降.利用循环伏安法分析了聚合物poly[Ni(salen)]的扩散动力学,结果表明在20 mV.s-1时制备的聚合物具有较大的电荷扩散系数.     

介电弹性体的研究进展

介电弹性体是一类在外加电场激励下可以发生形变,进行能量转换的新型纺织材料,属于电活性聚合物,电活性聚合物有电子型和离子型之分。介电弹性体在柔性驱动器的设计研究中有很广阔的应用前景,但是目前还存在很多技术难点,在弹性体基体材料构成、柔性电极材料优化,能量收集等方面仍然需更深入的研究。本文在明晰了介电弹性体的工作原理及分类后,对其在电极、预拉伸、温度和能量收集等方面进行了归纳总结,并对其应用前景进行了展望。     

Preparation and characterization of branched and linear sulfonated poly(ether ketone sulfone) proton exchange membranes for fuel cell applications

Branched sulfonated poly(ether ketone sulfone)s (Br‐SPEKS) were prepared with bisphenol A, bis(4‐fluorophenyl)sulfone, 3,3′‐disodiumsulfonyl‐4,4′‐difluorobenzophenone, and THPE (1,1,1‐tris‐p‐hydroxyphenylethane), respectively, at 180 °C using potassium carbonate in NMP (N‐methylpyrrolidinone). THPE, as a branching agent, was used with 0.4 mol % of bisphenol A to synthesize branched copolymers. Copolymers containing 10–50 mol % disulfonated units were cast from dimethylsulfoxide solutions to form films. Linear sulfonated poly(ether ketone sulfone)s (SPEKS) were also synthesized without THPE. The films were converted from the salt to acid forms with dilute hydrochloric acid. A series of copolymers were studied by Fourier transform infrared, ¹H‐NMR spectroscopy, differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). Sorption experiments were conducted to observe the interaction of sulfonated polymers with water and methanol. The ion‐exchange capacity (IEC), a measure of proton conductivity, was evaluated. The synthesized Br‐SPEKS and SPEKS membranes exhibit conductivities (25 °C) from 1.04 × 10^?3 to 4.32 × 10^?3 S/cm, water swell from 20.18 to 62.35%, IEC from 0.24 to 0.83 mequiv/g, and methanol diffusion coefficients from 3.2 × 10^?7 to 4.7 × 10^?7 cm²/S at 25 °C. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 1792–1799, 2008     

Synthesis and properties of hyperbranched poly(ether sulfone)s prepared by self‐polycondensation of novel AB2 monomer

Hyperbranched poly(ether sulfone)s were prepared by the self‐polycondensation of the novel AB₂ monomer, 4‐(3,5‐hydroxyphenoxy)‐4′‐fluorodiphenylsulfone. The high‐molecular‐weight polymers were isolated in good yields. The degree of branching (DB) of the resulting polymers was investigated by the preparation of dendritic and linear model compounds. The DB determined by gated decoupling ¹³C NMR measurements was in the range 0.17–0.41 and was dependent on the base used for the self‐polycondensation. It was found that cesium fluoride was an effective base to form the polymer having the DB of 0.41. The resulting hyperbranched poly(ether sulfone)s showed good solubility in organic solvents. The solubility and the glass transition temperature of the polymers were influenced by the terminal functional groups. The unique thermal crosslinking phenomenon was observed during the DSC measurements of the hydroxyl‐terminated hyperbranched poly(ether sulfone) under air condition. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

Copoly(arylene ether nitrile) and copoly(arylene ether sulfone) ionomers with pendant sulfobenzoyl groups for proton conducting fuel cell membranes

Three series of fully aromatic ionomers with naphthalene moieties and pendant sulfobenzoyl side chains were prepared via K₂CO₃ mediated nucleophilic aromatic substitution reactions. The first series consisted of poly(arylene ether)s prepared by polycondensations of 2,6‐difluoro‐2′‐sulfobenzophenone (DFSBP) and 2,6‐dihydroxynaphthalene or 2,7‐dihydroxynaphthalene (2,7‐DHN). In the second series, copoly(arylene ether nitrile)s with different ion‐exchange capacities (IECs) were prepared by polycondensations of DFSBP, 2,6‐difluorobenzonitrile (DFBN), and 2,7‐DHN. In the third series, bis(4‐fluorophenyl)sulfone was used instead of DFBN to prepare copoly(arylene ether sulfone)s. Thus, all the ionomers had sulfonic acid units placed in stable positions close to the electron withdrawing ketone link of the side chains. Mechanically strong proton‐exchange membranes with IECs between 1.1 and 2.3 meq g⁻¹ were cast from dimethylsulfoxide solutions. High thermal stability was indicted by high degradation temperatures between 266 and 287 °C (1 °C min⁻¹ under air) and high glass transition temperatures between 245 and 306 °C, depending on the IEC. The copolymer membranes reached proton conductivities of 0.3 S cm⁻¹ under fully humidified conditions. At IECs above ∼1.6 meq g⁻¹, the copolymer membranes reached higher proton conductivities than Nafion^® in the range between −20 and 120 °C. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

Selectively sulfonated poly(aryl ether sulfone)‐b‐polybutadiene for proton exchange membrane

A series of selectively sulfonated poly(arylene ether sulfone)‐b‐polybutadiene copolymers (SPAES‐b‐PB) were prepared based on carboxyl terminated polybutadiene (CTPB) and sulfonated poly(arylene ether sulfone) (SPAES) that was directly prepared by polycondensation of 4,4′‐isopropylidenediphenol with different molar ratios of disodium 3,3′‐disulfonate‐4,4′‐dichlorodiphenyl sulfone (SDCDPS) to 4,4′‐dichlorodiphenylsulfone (DCDPS), and subsequent selective postsulfonation of flexible PB block was carried out. Epoxidized modification of membranes was conducted by an in situ‐generated peracid method. The content of sulfonic acid groups attaching to aromatic rings in SPAES was determined by ¹H NMR and was in good aggrement with the controlled ratios. The effect of sulfonated rigid blocks on the postsulfonation of PB blocks was studied by Fourier transform infrared spectroscopy. The glass transition temperature (T_g) and the temperature of the melting peak (T) of membranes in acid form were studied by differential scanning calorimetry. Fenton's reagent test revealed that the selectively sulfonated SPAES‐b‐PB membranes had good stability to oxidation. The microstructure of rod‐like rigid SPAES blocks and interpenetrating network of ions were observed by transmission electron microscopy. Complex impedance measurement showed that an epoxidized membrane with SPAES‐40 exhibited the highest proton conductivity (1.08 × 10^?1 S/cm, 90 °C), which was due to the formation of obvious ionic networks. © 2006 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 44: 665–672, 2006     

Direct copolymerization of sulfonated poly(phthalazinone arylene ether)s for proton‐exchange‐membrane materials

Sulfonated poly(phthalazinone ether ketone) (SPPEK) copolymers and sulfonated poly(phthalazinone ether sulfone) (SPPES) copolymers containing pendant sodium sulfonate groups were prepared by direct copolymerization. The reaction of disodium 3,3′‐disulfonate‐4,4′‐difluorobenzophenone (SDFB‐Na), 4,4′‐difluorobenzophenone (DFB), and 4‐(4‐hydroxyphenyl)‐1(2H)‐phthalazinone (DHPZ) at 170 °C in N‐methyl‐2‐pyrrolidione containing anhydrous potassium carbonate gave SPPEKs. SPPESs were similarly obtained with 3,3′‐disulfonate‐4,4′‐difluorophenyl sulfone, 4‐fluorophenyl sulfone (DFS), and DHPZ as monomers. The sulfonic acid groups, being on deactivated positions of the polymer backbone, were expected to be hydrolytically more stable than postsulfonated polymers. Fourier transform infrared and ¹H NMR were used to characterize the structures and degrees of sulfonation of the sulfonated polymers. Membrane films of SPPEKs with SDFB‐Na/DFB molar feed ratios of up to 60/40 and SPPESs with sulfonated 4‐fluorophenyl sulfone/DFS molar feed ratios of up to 50/50 were cast from N,N‐dimethylacetamide polymer solutions. Membrane films in acid form were then obtained by the treatment of the sodium‐form membrane films in 2 N sulfuric acid at room temperature. An increase in the number of sulfonate groups in the copolymers resulted in an increased glass‐transition temperature and enhanced membrane hydrophilicity. The sodium‐form copolymers were thermally more stable than their acid forms. The proton conductivities of the acid‐form copolymers with sulfonated monomer/unsulfonated monomer molar feed ratios of 0.5 and 0.6 were higher than 10^?2 S/cm and increased with temperature; they were less temperature‐dependent than those of the postsulfonated products. SPPESH‐50 showed higher conductivity than the corresponding postsulfonated poly(phthalazinone ether sulfone). © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 2731–2742, 2003     

Sequence analysis of poly (ether sulfone) copolymers by 13C NMR

Random and block copolymers of poly (ether sulfone) (PES) and poly (ether ether sulfone) (PEES) were synthesized by the nucleophilic polycondensation of 4,4′‐dichlorodiphenyl sulfone (DCDPS) with 4,4′‐dihydroxydiphenyl sulfone (DHDPS) and hydroquinone (HQ). Chemical structures of these copolymers were characterized by ¹³C NMR. The monomer molar fraction, sequential distribution, and degree of randomness of the copolymers were determined through analyses of the resonances of quaternary carbons in the DCDPS unit. Experimental results show that the molar fractions of the comonomer determined by ¹³C NMR analyses are close to the charged values in the synthetic step. Moreover, these copolymers, which were prepared by different polymerization methods, revealed different number‐average sequential length and degree of randomness. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 1624–1630, 2005     

Organocatalyzed ring‐opening polymerization of cyclic butylene terephthalate oligomers

In this study, various organic compounds, with different activation modes, have been tested as catalysts for the ring‐opening polymerization (ROP) of cyclic butylene terephthalate oligomers (CBT) in bulk at 210 °C, using tert‐butylbenzyl alcohol (tBnOH) as initiator. Among them, 1,3,5‐triazabicyclo[4.4.0]dec‐5‐ene (TBD) appeared to be the most efficient, achieving high monomer conversions in short reaction times (within minutes). Analysis by size‐exclusion chromatography (SEC) of the poly(butylene terephthalate) (PBT) synthesized using this catalyst also showed that the polymerization follows the expected theoretical M _n trend for molecular weights up to 50 kg·mol^?1. Chain‐end fidelity relatively to the alcohol initiator has been confirmed by MALDI‐TOF mass spectroscopy, which showed that all polymer chains possess the tert‐butylbenzyl moiety as chain‐end. Finally, to demonstrate the potential of this system for the synthesis of PBT‐based block copolymers, a monomethyl ether poly(ethylene glycol) (PEG) of 5000 g·mol^?1 has been employed as initiator for the ROP of CBT. A PEO‐b‐PBT block copolymer of 15,000 g·mol^?1 could thus been obtained, as confirmed by the shift of the SEC traces towards higher molecular weights and the same diffusion coefficient determined for ¹H NMR signals of the PEO block and the PBT block. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55 , 1611–1619     

Partially fluorinated sulfonated poly(arylene sulfone)s blended with polybenzimidazole

A partially fluorinated and sulfonated poly(arylene sulfone) (SPSO) was successfully synthesized via nucleophilic polycondensation of 2,2‐bis(4‐fluorophenyl)hexafluoro‐propane with 4,4′‐thiobisbenzenethiol (TBBT). In a second step, the prepared poly(arylene sulfide) was oxidized to SPSO. The polymer was blended with the polybenzimidazole PBIOO^® to obtain a mechanically stable membrane. This film was compared with other polymer blends, which were synthesized in our group in the last years. We were especially interested in the influence of different bridging groups such as ether, ketone, and sulfone groups. The affect on properties such as water uptake (WU), thermal stability, proton conductivity, and oxidative stability were analyzed in this work. Additionally, the blend membranes were characterized by gel permeation chromatography. The novel SPSO blend shows a high molecular weight, and its blend membrane with PBIOO has an excellent onset of ? SO₃H group splitting‐off temperature (T_onset) of 334 °C. The proton conductivity amounts to 0.11 S cm^?1, and the water uptake reaches 30%. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

Synthesis of biocompatible and biodegradable block copolymers of polyvinyl alcohol‐block‐poly(ε‐caprolactone) using metal‐free living cationic polymerization

Applications of metal‐free living cationic polymerization of vinyl ethers using HCl · Et₂O are reported. Product of poly(vinyl ether)s possessing functional end groups such as hydroxyethyl groups with predicted molecular weights was used as a macroinitiator in activated monomer cationic polymerization of ε‐caprolactone (CL) with HCl · Et₂O as a ring‐opening polymerization. This combination method is a metal‐free polymerization using HCl · Et₂O. The formation of poly(isobutyl vinyl ether)‐b‐poly(ε‐caprolactone) (PIBVE‐b‐PCL) and poly(tert‐butyl vinyl ether)‐b‐poly(ε‐caprolactone) (PTBVE‐b‐PCL) from two vinyl ethers and CL was successful. Therefore, we synthesized novel amphiphilic, biocompatible, and biodegradable block copolymers comprised polyvinyl alcohol and PCL, namely PVA‐b‐PCL by transformation of acid hydrolysis of tert‐butoxy moiety of PTBVE in PTBVE‐b‐PCL. The synthesized copolymers showed well‐defined structure and narrow molecular weight distribution. The structure of resulting block copolymers was confirmed by ¹H NMR, size exclusion chromatography, and differential scanning calorimetry. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 5169–5179, 2009     

Synthesis and properties of amine‐containing poly(arylene ether sulfone) as an anion‐exchange matrix

Poly(arylene ether sulfone) (PSF), showing good thermal stability and excellent mechanical properties, was synthesized as an anion‐exchange matrix. It was synthesized by the condensation polymerization between bisphenol A and 4,4′‐dichlorodiphenylsulfone. 1°‐Amine‐containing poly(arylene ether sulfone) (1°‐APSF) was synthesized by the reduction reaction of a nitrated PSF. Then, it was transferred to 3°‐amine‐containing poly(arylene ether sulfone) (3°‐APSF) by the alkylation of the amine of 1°‐APSF. The properties of PSF, 1°‐APSF, and 3°‐APSF were investigated by Fourier transform infrared, ¹H NMR spectroscopy, differential scanning calorimetry, and thermogravimetric analysis. The introduction of the 3°‐amine group into PSF increased the glass‐transition temperature but decreased thermooxidative stability. The ion‐exchange capacities of 1°‐APSF and 3°‐APSF were shown to be 2.24 and 2.86 mequiv/g, respectively. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 4281–4287, 2002