Synthesis of a New Aromatic Dianhydride Containing Pyridine Ring and Related Polyimide

Aromatic polyimides are well known as high performance polymers owing to their excellent thermal stability, mechanical and electrical properties1,2. In the preparation of polyimides, aromatic dianhydride monomer plays a critical role3. Although aromatic t…     

Synthesis and Characterization of Organosoluble Polyimides Containing Pyridyl Moiety with Ether Linkages

Two novel diamine monomers, bis(4‐amino‐3,5‐dimethylphenyl)‐3‐pyridyl methane and bis(4‐aminophenoxy‐3,5‐dimethylphenyl)‐3‐pyridyl methane were synthesized. A series of pyridine containing aromatic polyimides derived from the diamines were synthesized through a typical two‐step polymerization method. Most of the polymers show good solubility in NMP, DMAc, DMF, DMSO and CHCl₃ at room temperature. These polyimides exhibit T_g in the range of 249–317°C and 10% wt loss (T₁₀) takes place in the range of 474–564°C in N₂ and 469–558°C in air. The polymers have tensile strength in the range of 88–96 MPa, elongation at break in the range of 8.5–12.5% and tensile modulus in the range of 1.5–2.1 GPa. These polyimides also have low dielectric constant (3.26–3.64 at 1 KHz and 3.24–3.61 at 10 KHz) and low moisture absorption (0.42–0.89%).     

乙二胺基乙磺酸钠的合成与表征

乙二胺基乙磺酸钠是水性聚氨酯合成中重要的亲水性扩链剂, 又可作为有机中间体、生化试剂应用于其它领域.采用乙二胺(EDA)和2-氯乙磺酸钠反应合成乙二胺基乙磺酸钠, 由红外光谱(FTIR)、核磁氢谱(1H NMR)和碳谱(13C NMR)、X射线衍射(XRD)、元素分析等手段表征了产物的结构与特性. 在EDA与2-氯乙磺酸钠物质的量比为6.5∶1时, 合成产物中乙二胺基乙磺酸钠含量高达94.4%. 产物极易溶于水, 微溶于甲醇, 乙醇, 不溶于丙酮, N,N-二甲基甲酰胺, 四氯化碳, 氯仿等有机溶剂.     

羟基中环二胺接枝壳聚糖的合成与表征

以具有环氧活性基的壳聚糖与3-羟基-1，5-二氮杂环庚烷或3-羟基1，5-二氮杂环辛烷反应，合成了两种含羟基的氮杂冠醚壳聚糖衍生物，其组成及结构经元素分析，IR，X-射线粉末衍射及^13C NMR等方法确证。     

Synthesis and Properties of Novel Polyimides Bearing Sulfonated Benzimidazole Pendant Groups

A new diamine monomer containing benzimidazole‐5‐sulfonic acid has been synthesised. It has been reacted, alone or mixed with diaminodiphenyl ether, with naphthalenic dianhydride to attain polynaphthalimides in which the sulfonic acid functionality is borne by pendant benzimidazole groups. The presence of sulfonic and benzimidazole groups greatly affected the physical properties of the polyimides as the novel polymers were found to be soluble in polar organic solvents and exhibited a lower thermal resistance than their non‐sulfonated counterparts. The polymer films exhibited good mechanical properties with tensile strength in the range 100–120 MPa and with moduli in the range 2.2–3.1 GPa. Sulfonic and benzimidazole groups significantly enhanced the hydrophilicity of the copolyimides, which showed water uptake up to 39%.

     

Synthesis of a New Asymmetrical Ether Diamine with Aromatic Structure and Related Polyimide

Aromatic polyimides are widely used in the microelectronic industry as electrical insulators, passivation layers, and liquid-crystal alignment layers, because of their excellent mechanical, electrical, chemical, and thermal properties1,2. Despite their ou…     

Synthesis and Properties of New Fluorinated Polyimides Derived from an Unsymmetrical and Noncoplanar Diamine

A new unsymmetrical and noncoplanar diamine containing trifluoromethyl and trimethyl groups, 1,4‐bis(4‐amino‐2‐trifluoromethylphenoxy)‐2,3,5‐trimethylbenzene ( 2 ), was synthesized using 2,3,5‐trimethylhydroquinone and 2‐chloro‐5‐nitrobenzotrifluoride as starting materials. A series of fluorinated poly(ether imide)s (PEIs) ( 4a–4d ) were prepared from diamine 2 with four aromatic dianhydrides via a one‐step high‐temperature polycondensation procedure. The obtained PEIs were readily soluble in most organic solvents and could be solution‐cast into flexible and strong films. The resulting thin films exhibited light color and good optical transparency with a cutoff wavelength of 356–376 nm. They also displayed good thermal stability with glass transition temperatures (T_g) above 281°C, 10% weight loss temperatures in the range of 482–486°C, and the weight residue more than 55% at 800°C in nitrogen. Moreover, they revealed low dielectric constants (2.77–2.93 at 1 MHz) and low moisture absorptions (0.41%–0.57%).     

Synthesis of a Novel Diamine 4-[(4''''-Butoxyphenoxy)carbonyl]phenyl-3",5"-diaminobenzoate and Corresponding Polyimides

A novel diamine 4-[(4'-butoxyphenoxy)carbonyl]phenyl-3",5"-diaminobenzoate (BCDA) was synthesized from 4-butoxyphenol, 4-hydroxybenzoic acid and 3,5-dinitrobenzoic acid through four main intermediates, and a series of polyimides were also synthesized. All the intermediates and the final product were characterized by FTIR and 1H-NMR. The key step in synthesis route is selective hydrolyzation of two ester groups in 4-butoxyphenyl-4'-acetoxybenzoate, by adjusting the reaction temperature and the concentration of ammonia, shorteding the reaction time. The properties of the novel polyimides, such as the aggregation structures, glass transition temperature, solubility and the pretilt angles, were carried out.     

Synthesis and Characterization of Soluble Polyimides Derived from 4,4′‐Diamino‐3,3′‐dimethyldiphenylmethane and Their Pervaporation Performances

Two kinds of soluble polyimides were synthesized from 4,4′‐diamino‐3,3′‐dimethyldiphenylmethane (DMMDA) and two dianhydrides (including BTDA, ODPA) via a two‐step method, low temperature solution polycondensation and next chemical imidization. All polyimides were readily soluble in common polar solvent, such as DMF, DMAc and NMP. The polyimides were characterized by FT‐IR, NMR, DSC, XRD and EA. The results showed that all of the polyimides revealed an amorphous nature and their inherent viscosities were 0.68–0.96 dlg^?1. The glass transition and melt temperature of these polyimides were determined by DSC and ranged from 224–283°C and 372–384°C, respectively. Thermogravimetric analysis indicated that these polyimides remained fairly stable up to a temperature around or below 400°C. Moreover, 10% mass losses were recorded at approximately 525°C in nitrogen atmosphere. They had a tensile strength in the range 89–137 MPa, and elongations breaking at around 10%. The pervaporation properties of the prepared polyimide dense membranes for ethanol/water mixtures were investigated at a different temperature and the average value of the separation factor and total permeation flux were 46–108 and 660–1380 g/m²h, respectively.     

新型双烯丙基化手性二胺的合成

通过烯丙基溴化锌对手性亚胺的两次不对称加成, 合成了光活性的双烯丙基化的新型手性二胺. 首先经N-Boc保护和Dess-Martin氧化制得了光活性的(S)-N-Boc-3-苯基-2-氨基丙醛. (S)-N-Boc-3-苯基-2-氨基丙醛与(S)-缬氨基酸甲酯缩合生成手性亚胺, 在七水合三氯化铈(CeC1₃•7H₂O)催化以及底物的手性诱导作用下, 该手性亚胺与烯丙基溴化锌经不对称加成反应合成了高光活性的单烯丙基化手性胺. 该手性胺与2-噻吩甲醛缩合生成新的手性亚胺, 再次通过不对称烯丙基加成反应合成了含有四个手性中心的高光学纯的双烯丙基化手性二胺. 目标化合物和关键中间体的结构均被¹H NMR, ¹³C NMR及MS确证.     

一种新型手性功能单体的合成

以手性芳胺为母体,丙烯酰氯为酰化试剂,合成了新型手性功能单体(1)。用1合成了一系列手性分子印迹聚合物。1的结构经1H NMR,IR,MS及元素分析确证。     

Polyimides with alicyclic diamines. II. Hydrogen abstraction and photocrosslinking reactions of benzophenone-type polyimides

Photosensitive polyimides with alicyclic diamines and benzophenone moiety were prepared by reactions of 3,3′,4,4′-benzophenonetetracarboxylic dianhydride (BTDA) with diamines in aprotic solvents, followed by thermal or chemical imidizations. Among them the polyimide from BTDA and bis(4-amino-3-methylcyclohexyl) methane (DMDHM) can be dissolved in several organic solvents such as dichloromethane, tetrachloroethane, and N-methyl-2-pyrrolidone (NMP). In order to compare properties of the polyimides with alicyclic diamines with those of corresponding aromatic polyimides, the UV absorption spectra and fluorescence spectra of these polyimides and their model compounds were investigated. No occurrence of charge transfer at photoexcited states was ascertained for the polyimides with alicyclic diamines. The hydrogen abstraction and crosslinking during photoirradiation have been studied to learn the influence of the elimination of charge transfer process in these photosensitive polyimides. The quantum yield of hydrogen abstraction for the model compound of alicyclic polyimides is 0.56 in THF measured with HPLC. The quantum yield for the photocrosslinking reaction of the solvent-soluble polyimide with alicyclic diamine, PI(BTDA/DMDHM), was determined to be 0.004 in air from gel permeation chromatography (GPC) measurement, which is four times higher than that for photosensitive polyimides with aromatic diamines. © 1994 John Wiley & Sons, Inc.     

Novel Cobalt (II) Phthalocyanine‐Containing Polyimides: Synthesis,Characterization, Thermal and Optical Properties

Summary: A novel class of polymer has been prepared by reaction of a copolyimide containing carboxylic acid groups, and a cobalt phthalocyanine peripherally substituted with a reactive hydroxyl group. The incorporation of the phthalocyanine ring was achieved by esterification of the carboxylic acid groups of the polyimide with the free hydroxyl group of the phthalocyanine. In this work, a limited number of phthalocyanine rings have been introduced in order to avoid extensive modification of the copolyimide properties. The extent of modification (percentage of esterified carboxylic groups) was estimated to be about 18%. The resulting material showed good thermal stability and a high glass transition temperature (above 300 °C). The incorporation of the bulky phthalocyanine ring brought about a light decrease of thermal properties, relative to those of the initial polyimide. The presence of phthalocyanine was confirmed by the absorption band at 670 nm showing in the visible region for the modified polyimide. The novel copolyimide also exhibited a remarkable emission peak at 430 nm, when excited at 350 nm, corresponding to the emission of the cobalt phthalocyanine moiety.

Schematic representation of the PI‐CoPc molecule and the chemical structure of the repeat unit.     

含肼聚酰亚胺的合成与表征

双(N-氨基酞酰亚胺)硫醚;溶解性;热性能     

Synthesis and Characterization of Novel N-Ferrocenesulfonyl Benzimidazole

A new series of ferrocenesulfonyl benzimidazle has been synthesized and characterized by 1H NMR, FT-IR and elemental analysis. They are expected to have special bio-activity.     

新型芳香吲唑酮类化合物的合成与表征

以p-取代苯胺为原料,经重氮化反应后再与2-氯乙酰乙酸乙酯反应制得(Z)-4-[2-(1-氯-2-乙氧基-2-羰亚甲基)肼基]-取代苯(2a～2i);在无水乙醇中,2a～2i分别与5,5-二甲基-1,3-环己二酮发生环化反应合成了9个新型的芳香吲唑类化合物(3a～3i),其结构经1H NMR和MS表征.     

Synthesis and Characterization of Novel Dimethylgallium Complexes

Recently, great attention has been paid to Group IIIA organometallic compounds owing to their wide range of uses in the areas of ceramic semi-conductor materials and diagnosis of diseases1. However, most of the relevant studies are limited to monoaminomethylated phenols as ligands2. In this paper, we report the synthesis of compounds (1a and 2a) as a new ligand and their dimethylgallium complexes (1b and 2b) (Scheme 1). General procedures for preparation of 1a, 2a and 1b, 2b were accorde…     

新型双氨类发光材料的合成与性能研究

以3-溴-9,9-二甲基芴为原料,通过Buchwald-Hartwig偶联反应合成了一种新化合物N,N′-二(联苯-4-基)-N,N′-二(9,9-二甲基芴-3-基)-9-苯基咔唑-2,7-二胺(2),其结构和性能经FL, UV-Vis, ¹H NMR, GC-MS(EI),元素分析和TG-DSC表征。结果表明：2具有较好的热稳定性和较高的玻璃化温度,失重5%的温度为452 ℃,玻璃化温度为176 ℃;在425 nm波长激发下,2在445 nm处发出较强荧光(蓝光)。     

Synthesis of Polyimides Containing Fluorine and Their Pervaporation Performances to Aromatic/Aliphatic Hydrocarbon Mixtures

Two kinds of polyimides containing fluorine were synthesized based on dianhydride of 2,2‐bis(3,4‐dicarboxyphenyl)hexafluoropropane dianhydride (6FDA) and diamines including 2,2‐bis[4‐(4‐aminophenoxy)phenyl] hexafluoropropane (BDAF) and 2,2‐bis[4‐(4‐aminophenoxy)phenyl]propane (BAPP) using solution condensation and following chemical imidization. The structures of 6FDA‐BDAF and 6FDA‐BAPP were characterized by FT‐IR, NMR, and XRD. Their glass transition temperatures characterized by DSC were in the range of 235–251°C, and the initial decomposition temperatures determined by TGA were over 540°C. The membranes of polyimide thus obtained were employed in pervaporation separation of aromatic/aliphatic mixtures. 6FDA‐BDAF membranes obtained better separation performances than 6FDA‐BAPP and had a flux of 0.66 kg · µm/m² · h and separation factor of 6.49 for toluene/n‐heptane (20/80 wt.%) at 80°C. The effects of the fluorine group on polyimides properties and separation performances were investigated.