含苯并咪唑单元可溶性聚酰亚胺的合成和性能

合成了一种刚性芳香二胺单体3,3',5,5'-四甲基-4,4'-二胺基苯基甲苯(BDAP),与6-氨基苯基-2-氨基苯并咪唑(BIA)组成混合二胺,分别与4种商品化的二酐单体(均苯四酸二酐(PMDA)、联苯四酸二酐(BPDA)、二苯酮四酸二酐(BTDA)和二苯醚四酸二酐(ODPA))一步法缩聚合成了一系列可溶性聚酰亚胺.采用FTIR,1H-NMR,UV-Vis,DMA和TGA等测试方法对所制备的聚酰亚胺进行了表征.结果表明,所制备的聚酰亚胺具有良好的溶解性能,能够在NMP和DMAc等常规溶剂中溶解;耐热性及力学性能优良,玻璃化转变温度超过410℃,分解温度在500℃以上.     

含氟及硫醚基团聚酰亚胺光波导材料的合成及表征

通过分子设计,合成了含三氟甲基及硫醚基团的二胺单体4,4'-双(4-胺基-2-三氟甲基苯硫基)二苯硫醚(6FSEDA),利用其与6种芳香二酐单体:3,3',4,4'-联苯四羧酸二酐(BPDA)、4,4'-氧双邻苯二甲酸酐(ODPA)、3,3',4,4'-二苯酮四酸二酐(BTDA)、4,4'-(六氟异丙基)-苯二酸酐(6FDA)、3,3',4,4'-二苯硫醚四酸二酐(DTDA)及3,3',4,4'-二苯砜四酸二酐(DSDA)经一步法合成了一系列含氟及硫醚基团的聚酰亚胺(PI),并对其结构与性能进行了研究.结果表明,该系列PI的玻璃化温度Tg(DSC)在199.8～231.7℃范围,5%和10%热失重的温度(N2氛围)分别在491℃和517℃以上,在400～700 nm的可见光波长范围内具有优异的光学透明性,在光通讯波段(1310 nm和1550 nm处)均无明显吸收,且在这两个波长处测得的平均折射率范围分别为1.5401～1.6142和1.5389～1.6124,在波长632.8 nm测得的双折射范围为0.0012～0.0045.可见,含氟及硫醚基团聚酰亚胺薄膜具有良好的热稳定性和光学性能.     

三明治结构含铅聚酰亚胺材料的制备与辐射屏蔽性能研究

采用离子交换法合成了以化学方式键合铅离子的二胺单体4,4'-二氨基-1,1'-联二苯-2,2'-二磺酸铅BDSA(Pb),并与二胺单体4,4'-二氨基-二苯醚(ODA),二酐单体均苯四甲酸酐(PMDA)在溶剂N-甲基-2-吡咯烷酮(NMP)中完成缩聚反应,通过改变2种二胺单体的摩尔比,采用热亚胺法和流延法逐层浇筑的工艺,制备出了一系列侧基键合铅离子的三明治结构的聚酰亚胺复合材料PI(Pb),试图解决传统物理共混方法制备的复合材料中易出现的铅元素分布不均匀、机械性能差的科学问题.实验结果表明:以纯PI为参照物,制备的PI(Pb)复合材料对~(241)Am(59.5 keV)、~(238)Pu(79.9、176.7 keV)等中低能γ射线具有很好的屏蔽效果,而且具备优良的耐辐照性能、优异的热稳定性能和良好的力学性能.     

基于苯醚型含氟二胺的聚酰亚胺膜材料的合成与表征

4,4′-二羟基二苯醚和2-氯-5-硝基三氟甲苯经Williamson反应得到4,4′-双(4-硝基-2-三氟甲基苯氧基)二苯醚;在Pd/C-水合肼还原作用下得到4,4′-双(4-氨基-2-三氟甲基苯氧基)二苯醚(p-6FAPE).采用3种苯醚型含氟二胺1,4-双(3-氨基-5-三氟甲基苯氧基)苯、1,4-双(4-氨基-2-三氟甲基苯氧基)苯和p-6FAPE分别与3,3′,4,4′-二苯醚四酸二酐(ODPA)和均苯四甲酸二酐通过两步法制备出6种含氟聚酰亚胺(PI),对其溶解性、热性能和光学性能进行研究.这些PI具有较好的溶解性,且具有良好的热稳定性;ODPA基PI在可见光波长范围具有优良的透明性,450 nm处的透光率超过80%.     

含哒嗪环聚酰亚胺的合成及性能表征

以马来酸酐为原料与水合肼反应得到哒嗪酮,再与三氯氧磷反应制备3,6-二氯哒嗪中间体,哒嗪中间体与间氨基苯酚通过亲核取代反应合成了一种新的二胺单体——3,6-二(3-氨基苯氧基)哒嗪.通过1HNMR,FTIR及HPLC-MS确证了哒嗪二胺及中间体的结构.这种哒嗪二胺单体与6种芳香二酐单体——均苯四甲酸二酐(PMDA)、3,3',4,4'-联苯四甲酸二酐(BPDA)、4,4-六氟异丙基邻苯二甲酸酐(6FDA)、3,3',4,4'-二苯甲酮四甲酸二酐(BTDA)、3,3',4,4'-二苯醚四甲酸二酐(ODPA)和双酚A型二醚二酐(BPADA)通过两步法聚合制备了一系列的聚酰亚胺,并对其结构和性能进行了研究.结果表明,聚酰胺酸的比浓对数黏度为0.37~0.50 dL/g,该系列聚酰亚胺膜具有良好的热稳定性和机械性能,玻璃化温度(Tg)为188~241℃,氮气氛围下5%和10%热失重分别为421~448℃和447~473℃,拉伸强度(TS)高达102 MPa,断裂伸长率(EB)为2.0%~6.5%.紫外可见光谱测试得到的截止波长(λcut-off)为367~389 nm.     

双酚F型聚酰亚胺的合成及其性能表征

以苯酚和甲醛为原料,合成了双酚F(BPF)和双酚F二酐(BPFDA),用BPFDA分别和间苯二胺(m-PDA)、4,4'-二氨基二苯醚(4,4'-ODA)、1,4-(4-氨基苯氧基)苯(TPEQ)反应,得到了3种双酚F型聚酰亚胺,分别对其结构、溶解性、热性能和力学性能进行了表征.结果表明:聚合物的比浓对数黏度为0.5～...     

氟取代聚芳醚酮低温合成及其结构研究

通过傅克酰基化反应合成4,4'-二(4-氟苯甲酰基)二苯醚、4,4'-二(五氟苯甲酰基)二苯醚、4,4'-二(4-氟苯甲酰基)二苯硫醚以及4,4'-二(五氟苯甲酰基)二苯醚4种长链双卤单体,并进一步制备了含二氮杂萘酮聚芳醚酮聚合物.通过多氟取代双卤单体在含二氮杂萘酮聚芳醚酮聚合物主链中引入氟原子.多氟取代双卤单体具有多...     

2,6-二[4''''-(3",4"-邻苯二甲酸酐苯氧基]苯基吡啶二甲酮的合成

芳香四酸二酐是有机芳杂环高分子如聚酰亚胺、聚吡咙等耐高温高分子的主要单体之一,但是由目前市售芳香四酸二酐所得芳杂环高分子多具有难溶难熔、不易加工的缺陷.因此,借助分子设计原理并应用有机合成手段,合成新型四酸二酐单体进而实现目标芳杂环高分子的改性研究则是十分重要的[1].合成具有柔性键、非共平面芳环取代基、含氟取代基、以及极性吡啶环等新型单体,既可保持聚合物的耐热性,又可改善其溶解性,赋予其优异的综合性能[2,3].本文依Scheme 1所示的设计路线,合成了聚合级的含有柔性醚键与极性羰基的新型含吡啶环四酸二酐单体、即2,6-二(4'-(3",4"-邻苯二甲酸酐苯氧基)苯基)吡啶二甲酮,其组成与结构已通过FT-IR,NMR,MS及元素分析证实.     

聚酰亚胺纤维及其纺丝工艺研究进展

聚酰亚胺纤维由于其优良的性能,已成为高技术纤维领域的研究热点之一.本文归纳了聚酰亚胺纤维的聚合单体,主要有二酐单体(均苯四甲酸酐、联苯四甲酸酐、二苯醚四酸二酐、二苯酮四酸二酐等)和二胺单体(二氨基二苯醚、对苯二胺、间苯二胺等).另外,还有第三单体,如嘧啶环二胺、氯化对苯二胺、二氨基二苯醚等,综述了聚酰亚胺纤维的主要纺丝...     

含磷聚酰亚胺纤维的制备与性能

合成了一种含磷二胺单体, 二(4-胺基苯氧基)苯基膦氧(DAPOPO). 该单体与4,4'-二胺基二苯醚(ODA)、 均苯四酸二酐(PMDA)和3,3',4,4'-联苯四酸二酐(BPDA)共聚得到聚酰胺酸溶液, 通过干喷湿纺法纺丝得到聚酰胺酸纤维, 聚酰胺酸纤维经过热亚胺化和热牵伸得到含磷的聚酰亚胺纤维. 利用纤维强度仪、 扫描电子显微镜、 热失重分析仪和氧指数测定仪等研究了含磷聚酰亚胺纤维的力学性能、 形貌、 热稳定性能和阻燃性能. 结果表明, 随着含磷量的增加, 纤维的热稳定性明显提高, 而极限氧指数从35上升到了45, 说明纤维的阻燃性能得到很大提高.     

多环芳二酐型聚酯亚胺膜的透气性能

多环芳二酐型聚酯亚胺膜的透气性能李悦生，丁孟贤，徐纪平（浙江大学高分子科学与工程研究所，杭州，３１００２７）（中国科学院长春应用化学研究所）关键词聚醚酰亚胺，聚酯酰亚胺，膜，透气性通常的聚酰亚胺加工性能较差，在芳环二酐的苯环间引入醚键等柔性基团后，其...     

微量元素与疾病诊断治疗的研究现状及展望

对国内外微量元素与疾病的关系及其诊断治疗的研究现状及研究动向进行了综述，包括：微量元素与地方病、癌肿、心血管病、糖尿病、眼病、神经系统病等。参考文献72篇。     

Determination and study on residue and dissipation of benazolin-ethyl and quizalofop-p-ethyl in rape and soil

A QuEChERS (quick, easy, cheap, effective, rugged, and safe) method for the determination of benazolin-ethyl and quizalofop-p-ethyl in rape and soil by high-performance liquid chromatography-tandem mass spectrometry has been developed in this study. The residue and dissipation of benazolin-ethyl and quizalofop-p-ethyl in rape and soil were determined with the developed method. The half-lives of benazolin-ethyl in rape straw and soil were 3.7–5.1 days and 14.3–26.3 days, respectively. The half-lives of quizalofop-p-ethyl in rape straw and soil were 5.0-6.1 days and 0.3–9.7 days, respectively. The residue of benazolin-ethyl and quizalofop-p-ethyl in rapeseed and soil were below the detection limit (i.e., 0.5?mg?kg^?1, the maximum residue level of European Union for quizalofop-p-ethyl).     

Synthesis and Optical and Redox Properties of Symmetric and Asymmetric BODIPYs

Herein, we present the synthetic route and the photophysical, electrochemical as well as laser properties of novel red‐emitting boron‐dipyrromethenes (BODIPYs) bearing arylethyne moieties. Such functionality is added along the main axis of the chromophore leading to single‐ and double‐substituted derivatives. The relationship between the dye structure and the lasing properties is studied in detail with the help of the photophysical and electrochemical properties as well as quantum mechanical simulations. The asymmetric substitution of the parent dye induces inhomogeneities in the charge distribution, which leads to an overall loss of the fluorescence capacity, mainly in polar media. Such non‐radiative deactivation processes can be softened by decreasing the electron‐donor ability of the substituent or even avoided by symmetrical substitution. Thus, grafting of the arylethyne moieties at the longitudinal axis of the indacene core results in an effective strategy to develop red‐edge BODIPYs with highly efficient and photostable laser emission.     

Ti-V基储氢合金及其氢化物的物相结构与组分优化设计

Ti-V基储氢合金在室温、常压下即可表现出良好的储氢特性,且质量储氢容量明显高于传统AB₅型储氢合金,从而在氢气的精制和回收、运输和储存及热泵等方面有较早的应用。 此外,在混合气体分离、核反应堆中处理氢的同位素、镍氢电池及燃料电池负极材料等方面也得到了广泛的研究与关注。 基于目前Ti-V基储氢合金的研究现状,概述了该类合金的优势、限制性因素(包括成因)及改性手段。 此外,为了进一步理解Ti-V基合金储氢机理、构建合金组分与储氢特性之间的对应关系,本工作重点围绕Ti-V基储氢合金及其氢化物的结构、组分优化设计展开综述,并对其未来研究方向做出展望。     

钒与糖代谢及糖尿病

微量元素钒作为生物体内必需元素，经证实有很重要的生理学功能，与机体糖代谢有十分密切的关系，且能降低糖尿病动物模型的高血糖，极有可能被开发为治疗糖尿病的药物。     

Conformations and steric and stacking interactions of trisubstituted ureas and thioureas with alkyl and phenyl groups

The monomeric ν(N—H) vibrations of various trisubstituted ureas of the R₂UPh type and -thioureas of the R₂TUPh type have been studied. The trans—out isomerism in the former and the trans—out—cis isomerism in the latter are discussed from the point of view of steric effect. The monomeric ν(N—H) vibrations of RPhUPh and RPhTUPh are also examined. The single band appearing in the spectrum of both ureas is characteristic of the cis form; this suggests the existence of phenyl—phenyl interaction (the stacking interaction proposed by Galabov et al. [10]). Behavior of ν(N—H) vibrations at several concentrations is shown to be clearly different in the three forms (trans, out and cis). The presence of the cis form is confirmed by solvent effect experiments.     

Synthesis of Tyrosol and Hydroxytyrosol Glycofuranosides and Their Biochemical and Biological Activities in Cell-Free and Cellular Assays

Tyrosol (T) and hydroxytyrosol (HOT) and their glycosides are promising candidates for applications in functional food products or in complementary therapy. A series of phenylethanoid glycofuranosides (PEGFs) were synthesized to compare some of their biochemical and biological activities with T and HOT. The optimization of glycosylation promoted by environmentally benign basic zinc carbonate was performed to prepare HOT α-L-arabino-, β-D-apio-, and β-D-ribofuranosides. T and HOT β-D-fructofuranosides, prepared by enzymatic transfructosylation of T and HOT, were also included in the comparative study. The antioxidant capacity and DNA-protective potential of T, HOT, and PEGFs on plasmid DNA were determined using cell-free assays. The DNA-damaging potential of the studied compounds for human hepatoma HepG2 cells and their DNA-protective potential on HepG2 cells against hydrogen peroxide were evaluated using the comet assay. Experiments revealed a spectrum of different activities of the studied compounds. HOT and HOT β-D-fructofuranoside appear to be the best-performing scavengers and protectants of plasmid DNA and HepG2 cells. T and T β-D-fructofuranoside display almost zero or low scavenging/antioxidant activity and protective effects on plasmid DNA or HepG2 cells. The results imply that especially HOT β-D-fructofuranoside and β-D-apiofuranoside could be considered as prospective molecules for the subsequent design of supplements with potential in food and health protection.     

Ferrocene and ferrocenium modified clays and their styrene and EVA composites

In this work, ferrocene- and ferrocenium-containing salts were employed to modify montmorillonite. X-ray measurements show an increase in the interlayer spacing upon clay modification, which means that the larger and more organophilic cations were inserted into the gallery space of montmorillonite. Attempts to prepare nanocomposites of polystyrene and ethylene vinyl acetate copolymers lead to immiscible systems; the morphology of these systems was elucidated with TEM, XRD and cone calorimetry. The thermal stability of the composites is greater than that of the virgin polymer.