苝二酸酐与嘧啶衍生物的氢键组装

用半经验AM1方法对苝二酸酐与嘧啶衍生物的1:1及1:2氢键复合物进行理论研究,表明随着氢键数目增多,弱相互作用能变大,主体上的供电基和客体上的吸电基有利于氢键相互作用,氢键导致电子从主体流向客体.用INDO/SCI方法计算配合物的电子光谱,表明其长波吸收峰与主体相比发生兰移,各配合物的长波吸收峰位置相差不大,与实验一致.讨论吸收峰兰移的原因并对电子跃迁进行理论指认,同时得到了配合物的双质子转移势能曲线,给出了相对于N-H键的过渡态和活化能.     

Melt-polymerizable bisimido-bisphthalonitriles containing silicon,fluoro, and ether groups: Synthesis,characterization, and NMR study

Various melt-polymerizable bisimido-bisphthalonitrile polymer precursors were synthesized by the reaction of 4-aminophthalonitrile (4-APN) with bis(3,4-dicarboxyphenyl) dimethylsilane dianhydride (SIDA), 4,4′-hexafluoroisopropylidene diphthalic anhydride (6FDA), bis(3,4-dicarboxyphenyl)ether dianhydride (ODPA), and 3,3′, 4,4′-tetracarboxylichenzophen+ne dianhydride (BTDA) in an aprotic solvent. The synthesized monomers showed crystalline melting at 269 and 271°C. Elemental analysis, differential thermal analysis (DTA), infrared (IR), nuclear magnetic resonance (¹H-NMR) and mass spectral studies were carried out to characterize the synthesized monomers. Thermogravimetric analysis (TGA) of the synthesized monomers showed their thermal stability at 410–400°C. A detailed study and NMR investigation of the first step of condensation reaction was carried out and indicated the formation of a transient charge transfer complex. Thermal cyclization of the formed intermediate, however, gave the required monomers. A preliminary study demonstrated that melt-polymerization of the synthesized monomers gave thermallystable, tough polymers.     

热致性液晶聚酯酰亚胺高分子的合成

本文以己二胺，癸二胺和对－亚苯基－双苯偏三酸酯二酐为单体通过溶液聚合反应制备了聚酯酰亚胺系列共聚物．采用ＩＲ，ＷＡＸＤ，ＤＳＣ和偏光显微镜研究了共聚物的结构和液晶性能，结果表明，聚合物具有热致液晶性，且随二胺单体摩尔组成的变化，共聚物的熔点Ｔｍｌ和玻璃化转变温度Ｔ８呈规律性变化．     

An effective and regioselective bromination of 1,4,5,8-naphthalenetetracarboxylic dianhydride using tribromoisocyanuric acid

A highly efficient and cost-effective reagent for the bromination of 1,4,5,8-naphthalenetetracarboxylic dianhydride under mild reaction conditions is reported. Bromination of 1,4,5,8-naphthalenetetracarboxylic dianhydride using tribromoisocyanuric acid (TBCA) in concentrated H₂SO₄ is very effective and regioselective. 1,4,5,8-Naphthalenetetracarboxylic dianhydride was brominated smoothly under optimized reaction conditions to give mono-, di- and tetra-brominated products in good to excellent yields using TBCA. As a proof of principle, the potential of this bromination methodology is demonstrated by converting brominated naphthalenetetracarboxylic dianhydrides into N-imide and core functionalized 1,4,5,8-napthalenetetracarboxylic diimides by treating with n-butylamine to yield corresponding mono-, di- and tetra-(n-butylamino)-naphthalene diimides in good yields in one-step reactions.     

热固性聚酰亚胺基体树脂的流变行为

热固性聚酰亚胺基体树脂的流变行为;聚酰亚胺;二苯醚二酐;二苯硫醚二酐;苯乙炔苯酐;流变     

新型乙炔封端聚酰亚胺的制备及性能

用双酚A型二醚二酐(BPADA)和3-乙炔基苯胺(m-APA)进行缩聚反应合成了乙炔基封端的聚酰亚胺预聚体, 并对预聚体的熔体黏度、稳定性和热性能等进行研究. 结果表明, 此类预聚体具有较宽的加工窗口和较低的加工温度, 适合模压成型工艺制备树脂基复合材料. 预聚体经250 ℃固化后显示了优异的热性能, 动态力学分析显示其玻璃化转变温度为363 ℃, 在氮气和空气气氛下5%热失重温度分别为490和492 ℃.     

均苯四甲酸酐改性花生壳粉吸附阳离子红染料的研究

以花生壳粉(PS)为生物基质,甲苯-2,4-二异氰酸酯(TDI)为交联剂,均苯四甲酸酐(PMDA)为改性剂,制备了均苯四甲酸酐改性花生壳粉(PMPS)吸附剂,并研究了PMPS对阳离子红染料吸附效果的影响因素。结果表明,在25℃,吸附时间3 h,pH值为2.0时,PMPS处理浓度为400.0 mg/mL的阳离子红溶液25 mL,最大吸附容量Q为177.2 mg/g,是未改性花生壳粉的2.2倍。改性花生壳粉吸附模式为Langmuir单分子层化学吸附。     

新型水溶性超支化聚酰胺-酯的合成

均苯四甲酸酐与二乙醇胺经酰化反应制得中心核(4);4与AB2单体2,2-二羟甲基丙酸经熔融缩聚合成了一种新型水溶性的二代超支化聚酰胺-酯(1),其结构与性能经FT-IR,GPC,粘度法,化学滴定等表征。4的Mn=1 683,Mw=1 911,Mw/Mn=1.14,[ηinh]=0.067 6 dL·g-1;1的Mn=3 750,Mw=4 904,Mw/Mn=1.31,[ηinh]=0.086 1 dL·g-1。     

Hydrolytic Ring Opening Reactions of Pyromellitic Dianhydride for Divalent Transition Metal Carboxylate Complexes

The hydrolytic ring opening reactions of pyromellitic dianhydride is an effective method to prepare transition metal carboxylate complexes. In this paper, two dinuclear complexes [Ni₂(2,2′‐bipy)₂(btec)(H₂O)₆] · 2H₂O ( 1 ) and [Cd₂ (phen)₄(H₂O)₂(H₂btec)] · H₂btec · 2H₂O ( 2 ) (H₄btec = 1,2,4,5‐benzenetetracarboxylic acid, phen = 1,10‐phenanthroline, and 2,2′‐bipy = 2,2′‐bipyridine) were synthesized by slow diffusion methods and their structures were determined byX‐ray structure analysis. In both structures metal atoms are in distorted octahedral environments and they are linked by bis‐monodentately coordinated 1,2,4,5‐benzentetracarboxylate ligands as bridging units. The crystalline compounds, which are insoluble in water as well as common organic solvents, have been characterized in the solid‐state by elemental analysis, thermogravimetric analysis, IR, and diffuse reflectance UV/Visspectroscopy. Moreover, the study of the physical properties of complex 2 demonstrates that it exhibits blue fluorescence emission in the solid state at room temperature.     

A novel efficient synthetic method for 2,2＇,3,3＇-biphenyltetracarboxylic dianhydride

A novel approach to the synthesis of 2,2',3,3'-biphenyltetracarboxylic dianhydride is described. The target compound was prepared by a nickel-catalyzed coupling reaction of dimethy 3-chlorophthalate (3-DMCP) for 4 h at 70-80℃, followed by subsequent hydrolysis of tetra-ester in acid solution and dehydration of tetra-acid, with overall yield of 68%. The structures of the products were characterized by IR, ¹H NMR and ¹³C NMR respectively.