磺化聚苯醚酮质子交换膜的制备与表征

设计、合成了一种含氰基双氯单体,其结构特点是氰基分布在3个以间位醚键相连的苯环上。以此单体和2,5-二氯-3'-磺酸钠二苯甲酮为原料,利用Ni(0)催化偶联反应制备了微嵌段型质子交换膜材料(中等长度磺化聚苯-三氰基聚苯醚酮共聚物(m-SPP-co-PAEK 3CN x),x代表聚合物的离子交换容量)。结果表明,与相同离子交换容量的磺化聚合物相比,该类聚合物膜表现出较低的吸水、溶胀率和较低的甲醇渗透性能。以离子交换容量2.16为例,80℃下,m-SPP-co-PAEK 3CN 2.16的吸水率、溶胀率分别为29.7%、28.2%,而SPP-co-PAEK MO 2.33的吸水率、溶胀率分别为80.2%、37.2%。25℃下,二者的甲醇渗透系数分别为2.38和7.20。聚合物骨架结构中存在丰富的氰基基团,导致膜具有良好的尺寸稳定性和较低的甲醇渗透性能。基于这些优异的性能,新制备的膜材料在燃料电池领域显示了潜在的应用前景。     

含氰基侧基聚芳醚砜的合成与表征

汉２，６－二卤苯甲腈、４，４′－二氯二苯砜、４，４′－二羟基二苯砜、间苯二酚、对苯二酚、酚酞及双酚Ａ为主要原料，合成了含不同结构单元和不同氰基含量的含氰基侧基的聚芳醚砜，并采用ＩＲ、＾１３ＣＮＭＲ等分析手段对其结构进行了表征，同时研究了结构单元和氰基含量对聚芳醚砜性能的影响。     

含氰基高性能聚芳醚材料的合成与表征

将合成的含氰基的双二氮杂萘酮单体与二氟芳香单体进行亲核取代反应, 制备了三种含氰基的新型聚芳醚, 并用TGA, DSC和GPC等分析手段对其综合性能进行表征. 结果表明, 含氰基聚芳醚具有优异的热稳定性(T5%>492 ℃)、较高的玻璃化转变温度(Tg=262~320 ℃)和良好的溶解性能, 易溶于氯代烷烃(如氯仿)和极性非质子性溶剂(如DMAc, DMF, NMP等).     

氰基二苯乙烯基超分子聚合物的构筑与光响应行为

通过在氰基二苯乙烯基元上引入氢键识别位点，驱使单体分子之间产生氢键与π-π堆积作用力的高效加合，构建了具有“成核-链增长”机制的超分子聚合物。通过获取组装热力学参数，揭示了酰胺及脲等不同氢键结构对于超分子聚合行为的影响规律。进一步利用超分子聚合态对于氰基二苯乙烯基元的限域效应，光照条件下特异性获得[2+2]环加成产物。与之相比，单体态时氰基二苯乙烯基元倾向于发生Z/E光异构化反应。这一研究结果可为多路径光化学反应的高效调控提供新的思路。     

过充保护添加剂氰基功能化2, 5-二叔丁基对苯二酚的合成及其在锂离子电池中的应用

设计合成了单氰基功能化的2, 5-二叔丁基-1-（β-氰基乙氧基）-4-甲氧基苯（RS-MCN）和双氰基功能化的2, 5-二叔丁基-1, 4-（β-氰基乙氧基）苯（RS-DCN）,并用作氧化还原过充添加剂开展了其在锂离子电子中的应用研究。通过丙烯氰和2, 5-二叔丁基对苯二酚的迈克尔加成反应可高效合成RS-MCN和RS-DCN,氰乙基取代后的过充保护添加剂分子的可逆氧化还原电位分别为4.02、4.08 V（vs Li/Li⁺）;并且单氰基取代的RS-MCN在商业碳酸酯电解液1 mol·L^-1 LiPF6/EC+DEC+EMC（1：1：1,体积比）中的溶解度可高达0.3 mol·L^-1。RSMCN和RS-DCN对LiFePO₄/Li电池的过充保护性能和电极相容性也进行了深入的研究,实验结果表明：RSMCN具有更好的过充保护性能和电极相容性,其5 V截止电压过充保护时间可超过1200 h,100%过充保护大于90周循环;0.3 mol·L^-1 RS-MCN的添加能使100%过充的LiFePO₄/Li电池在2.5C倍率条件下正常循环,其放电比容量达153.5 mAh·g^-1。此外,RS-MCN的添加对LiFePO₄/Li电池在2.5-3.8 V条件下的循环性能有明显改善,添加有RS-MCN的电池在60周的循环后容量保持率高达94.4%,而商业电解液的电池在60周循环后的容量保持率降至84.3%。因此,氰基功能化RS-MCN是一类具有潜在应用前景的过充保护添加剂。     

可见光光氧化还原催化的三级胺α位C-H氰基化反应

报道了可见光光氧化还原催化的三级胺α-位碳-氢键的氰基化反应.该反应使用高价碘氰基试剂作为安全的氰基源,避免生成剧毒的氰基负离子、无需使用额外的氧化剂,具有反应条件温和、官能团兼容性好、操作简便安全等优点.此外,通过应用可见光光氧化还原催化策略,首次实现了可见光催化的烷基羧酸在温和条件下的脱羧氰基化反应.这些反应为α-氨基腈类化合物和烷基腈类化合物的合成提供了一种有效的方法.     

本体溶液法合成超高分子量聚苯乙烯

对２，３－二氰基－２，３－二苯基丁二酸二乙酯引发苯乙烯本体溶液聚合，合成超高分子量聚苯乙烯的宏观动力学进行了研究。结果表明，这种引发剂在苯乙烯中引发聚合性能温和，在一定条件下，随反应时间的增长，聚合产物的分子量不断增高，可形成超高分子量聚合物。     

5-取代-1-氢四唑合成中捕获的一个新奇的三维镉配聚物(英)

在水热条件下，1，4-对二氰基苯，氯化镉以及叠氮化纳反应,成功地组装了一个三维网状镉四唑配位聚合物[monoaqua-4-tetrazolyl-benzenecarboxylate cadmium(Ⅱ)(1)],该化合物并不是预期的双四唑镉配位聚合物，而是其中一个氰基水解成羧基形成了单四唑镉配位聚合物。晶体结构分析表明，化合物1具有PtS的拓扑结构，室温下，化合物1显示强的蓝色荧光。     

合成医用粘接剂中α-氰基丙烯酸乙酯的分光光度法测定

１引言α－氰基丙烯酸乙酯作为一类新型医用粘合剂，具有粘合此血作用快，组织反应轻、可被机体吸收等诸多优点作为医用材料，对α－氨基丙烯酸乙酯的性能指标应有严格要求，因而合成工艺校为复杂．为了提高产品质量，降低成本在生产过程中必须对ａ－氰基丙烯酸乙酯进行定量分析．关于α－氰基丙烯酸乙酯的定量分析．只有文献提及用元素分析法显然该法不适宜生产过程的质量控制、由于α-氰基丙烯酸乙酯容易发生聚合，色谱分析存在困难．因此我们建立了α－氰基丙烯酸乙酯分光光度法的快速定量分析．２实验部分Ｚｔｌ仪器与试剂岛津ＵＶ．２…     

新型三维配位聚合物[Fe(C_5H_4NCOO)_2]_n的可控合成、晶体结构和UV-VIS-NIR反射光谱研究

近年来，金属有机配位聚合物由于其独特的电学、磁学、催化和光学性能而受 到普遍关注。通过选择不同的多齿配体和金属离子，可以组装成具有各处新型骨架 结构和特殊物理化学性能的配位聚合物。异烟酸根可以通过吡啶环氮原子和羧基氧 原子与金属离子配位，生成配位聚合物。本文采用三氯化铁和4-氰基吡啶在水热条 件下的反应可控地合成具有三维骨架结构的配位聚合物[Fe(C_5H_4NCOO)_2]_n，并 进行元素分析、红外光谱表征，单晶结构测定和UV-VIS-NIR（紫外-可见-近红外） 反射光谱研究。     

Determination of antioxidant migration levels from low-density polyethylene films into food simulants

An analytical method for the determination of specific migration levels of phenolic antioxidants from low-density polyethylene (LDPE) into food simulant has been developed. The screening and response surface experimental designs to optimize the liquid-liquid extraction (LLE) of these antioxidants have been tested and the analyses have been carried out by reversed-phase high-performance liquid chromatography (HPLC) coupled with ultraviolet diode-array detector. The procedure developed has been applied to specific migration tests in different commercial LDPE films. The considered antioxidants have not been found upper the legislation limits although Ethanox 330 and Irgafos 168 have been found at trace level.     

高分子树脂合成技术特色实验教学改革初探

实验教学在高分子材料科学中占据着十分重要的地位。为进一步突出实验教学内容的专业特色、强化学生专业技能、提升学生的创新与科研能力,在原有综合实验教学体系的基础上,以耐烧蚀性酚醛树脂的研究为典型,为高分子方向的四年级本科生增设了一门更具专业特点的高分子树脂合成技术特色实验,进而实现人才培养的目标。     

Investigation of phenolic acids in yacon (Smallanthus sonchifolius) leaves and tubers

Thin-layer chromatographic (TLC) screening of crude extracts of dried leaves and tubers of yacon (Smallanthus sonchifolius, Asteraceae) and products of acid hydrolysis of tubers on the silica gel HPTLC plates using the developing solvents ethyl acetate-formic acid-water (85:10:15, v/v/v) and n-hexane-ethyl acetate-formic acid (20:19:1, v/v/v) proved the presence of chlorogenic, caffeic and ferulic acid. These phenolic acids were isolated from the crude extract of yacon leaves by preparative TLC, and identified after elution by HPLC/MS, as well as by direct injection of the crude extract into the HPLC/MS system. Acid hydrolysis of tubers released the increased amount of phenolic acids (e.g. caffeic acid and ferulic acid), flavonoid quercetin and an unidentified flavonoid, which was detected by TLC analysis. Ferulic acid, isomers of dicaffeoylquinic acid and still an unidentified derivative of chlorogenic acid (Mr = 562) as constituents of yacon leaves and ferulic acid as constituent of yacon tubers are reported here for the first time. These acids gave significant contribution to the radical scavenging activity detected directly on the TLC plate sprayed with 1,1-diphenyl-2-picrylhydrazyl (DPPH).     

Conductimetric and potentiometric titrations of phenolic acids with triethylamine and tetrabutylammonium hydroxide in acetonitrile

Nineteen phenolic acids, namely phenol, 2-nitrophenol, 3-nitrophenol, 4-nitrophenol, 2,4-dinitrophenol, 2,5-dinitrophenol, 2,6-dinitrophenol, 2,4,6-trinitrophenol, 4-chlorophenol, 2,4,6-trichlorophenol, 1,2-dihydroxybenzene, 1,3-dihydroxybenzene, 1,4-dihydroxybenzene, 1,2,3-trihydroxybenzene, 2-aminophenol, 3-aminophenol, 4-aminophenol, 3-cresol and 4-cresol, were titrated conductimetrically and potentiometrically with triethylamine and tetrabutylammonium hydroxide in acetonitrile under a nitrogen atmosphere at 25°C. Most exhibited normal behaviour on titration with triethylamine, but only 2,4-dinitrophenol, 2,6-dinitrophenol and 2,4,6-trinitrophenol gave useful characteristic and stoichiometric conductimetric titration curves. None of the compounds gave a meaningful conductimetric titration curve on titration with tetrabutylammonium hydroxide, which is a much stronger base than triethylamine. With three exceptions, all compounds exhibited stoichiometric well shaped potentiometric titration curves. Potentiometric titration curves of the phenolic acids with tetrabutylammonium hydroxide in acetonitrile are very similar to those of strong acids obtained in aqueous media with strong bases. Acetonitrile is a suitable solvent for titrating some of the weak phenolic acids conductimetrically with triethylamine, and is an excellent medium for titrating them potentiometrically with tetrabutylammonium hydroxide under a nitrogen atmosphere at 25°C.     

Analyses of phenolic compounds by microemulsion electrokinetic chromatography

In this study, a microemulsion electrokinetic chromatography (MEEKC) method was developed to analyze and detect 13 phenolic compounds (syringic acid, p-cumaric acid, vanillic acid, caffeic acid, gallic acid, 3,4-dihydroxybenzoic acid, 4-hydroxybenzoic acid, (+)-catechin, (-)-epigallocatechin, (-)-epicatechin gallate, (-)-epigallocatechin gallate, (-)-epicatechin, and (-)-gallocatechin), which are present in many plant-derived foods. The effects of cosurfactant, organic modifier, and oil were examined in order to optimize the separation of these phenolic compounds. The amounts of cosurfactant (cyclohexanol) and organic modifier (acetonitrile) were determined as the major influence on the separation selectivity, while the type of oil partially affected the separation resolution of the phenolic compounds. A highly efficient MEEKC separation method was achieved within 14 min by using a microemulsion solution of pH 2.0 containing 2.89% w/v SDS, 1.36% w/v heptane, 7.66% w/v cyclohexanol, and 2% w/v ACN. Furthermore, the present work could demonstrate that the nature of the oil phase has a significant influence on the separation selectivity of phenolic compounds.     

Determination of phenolic acids and flavonoids of apple and pear by high-performance liquid chromatography

A new HPLC stationary phase has been applied to the analysis of phenolic acids and flavonoids with diode array and mass spectrometric detection. The separation of 26 standard compounds was achieved within 1 h. The stationary phase displayed excellent resolution especially of flavonol glycosides. The analytical system has been used for the determination of phenolic compounds in apple pomace and apple juice, and in extracts of pear fruits of different cultivars. Apple pomace was found to be a promising source of phenolics. However, yields are affected by the drying conditions applied. Furthermore, the applicability of the analytical system for the authenticity control of apple and pear juice was demonstrated by determination of characteristic quercetin and isorhamnetin glycosides, and dihydrochalcones, respectively. Since isorhamnetin-3-glucoside was present in all pear cultivars investigated, the usefulness of arbutin as a specific marker of pear products appears to be doubtful.     

Determination of chlorogenic acid in rat blood by microdialysis coupled with microbore liquid chromatography and its application to pharmacokinetic studies

To investigate the pharmacokinetics of unbound chlorogenic acid, a sensitive microbore liquid chromatographic method for the determination of chlorogenic acid in rat blood by microdialysis has been developed. A microdialysis probe was inserted into the jugular vein of male Sprague–Dawley rats, to which chlorogenic acid (20, 40, 60 or 80 mg/kg, i.v.) had been administered. On-line microdialysate was directly injected into a microbore column using a methanol–100 mM sodium dihydrogenphosphate (30:70, v/v, pH 2.5 adjusted with orthophosphoric acid) as the mobile phase and ultraviolet detection at 325 nm. The method is rapid, easily reproduced, selective and sensitive. The limit of detection for chlorogenic acid was 0.01 μg/ml and the limit of quantification was 0.05 μg/ml. The in vivo recovery of the chlorogenic acid of the microdialysis probe, based on a 5 μg/ml standard, was approximately 49–65% (n=6). The disposition of chlorogenic acid at each dose was best fitted to a two-compartment pharmacokinetic model. The area under the concentration curve increased greater than in direct proportion with the dose and terminal disposition become much slower as the dose was increased. The results indicated that the pharmacokinetics of unbound chlorogenic acid in rat blood is non-linear.     

Two New Phenolic Compounds from the Rhizomes of Gastrodia elata Blume

Phytochemical investigation of the rhizomes of Gastrodia elata Blume (Orchidaceae) led to the isolation and identification of twelve compounds, including two new phenolic compounds, 4‐hydroxybenzyl vanillyl ether (=4‐{[(4‐hydroxyphenyl)methoxy]methyl}‐2‐methoxyphenol; 1 ) and 4‐{{4‐[4‐(methoxymethyl)phenoxy]benzyl}oxy}benzyl methyl ether (=1‐[4‐(methoxymethyl)phenoxy]‐4‐{[4‐(methoxymethyl)phenoxy]methyl}benzene; 2 ). The structures of 1 and 2 were elucidated by spectroscopic data analysis including 1D‐ and 2D‐NMR experiments.     

Three New Phenolic Compounds from Nepeta Prattii

Three new phenolic compounds, 2‐(glycer‐2‐yl)‐5‐(2‐hydroxyethyl)phenyl‐O‐β‐D‐glucopyranoside, 2‐(glycer‐2‐yl)‐5‐(2‐hydroxyethyl)phenyl‐O‐β‐D‐galactopyranoside and ethyl 3‐(3,4‐dihydroxyphenyl)lactate were isolated from Nepeta prattii. Their structures were elucidated by spectral methods.