母体苯胺六聚体的一步法合成及紫外光谱研究

作为聚苯胺模型化合物的齐聚物具有规整的分子结构、良好的电活性以及易加工性能 ,使得齐聚物的研究成为导电高分子研究领域的一个研究热点 .结果表明 ,聚苯胺八聚体对有机气体的敏感性是聚苯胺的 1 0 0 0倍 [1] ,并且导电率与之相似 ,而苯封端苯胺三聚体及四聚体在金属防腐方面也显示了优良的抗腐蚀性 [2 ] .因此 ,合成具有不同链段的聚苯胺齐聚物 (母体苯胺齐聚物以及包括苯基封端 /氨基封端在内的苯胺齐聚物及其衍生物 )就变得十分重要 .合成聚苯胺齐聚物已有许多文献报道 ,如Honzl等 [3]的缩聚法、Monkman[4 ]的取代还原法和 Buchwald…     

苯胺齐聚物对聚苯胺微纳米形貌形成的影响

聚苯胺是一种具有优异性能的导电高分子材料,在传感器、防腐、电容器、生物等领域有着广泛的应用前景。化学氧化聚合法是制备聚苯胺的常用方法。苯胺齐聚化是苯胺化学氧化聚合过程中的重要一步,不同条件下生成的齐聚物化学结构及其自组装方式的差异会导致最终聚苯胺的形貌迥异。本文结合目前人们较为认同的聚苯胺微纳米结构形成机理,基于产物形貌分类,综述了在化学氧化过程中的苯胺齐聚化反应和苯胺齐聚物自组装引导聚苯胺微纳米结构的形成,讨论了目前研究中的存在的问题并对今后研究方向进行了展望。     

刚性环状低聚物的二维有序单分子膜结构

近十年来 ,为了解决耐高温高分子材料加工温度高、熔体粘度大等问题 ,材料学家们研制和开发了一系列刚性环状齐聚物 ,如环状聚芳醚酮[1] 、环状聚芳醚砜[2 ] 和环状聚苯硫醚[3] 等 .但早期人们主要把含有刚性链段的环状齐聚物 (RCO)作为结构材料研究 .1 993年 ,Miyashita[4 ] 等发现 ,含有近似刚性的酰胺键的手性环状二苯胺低聚物具有与经典 LB分子相似的双亲性 ,可以获得手性 LB膜 .近来我们合成了一系列直径可控、含有不同活性功能基团的 RCO.RCO是一类潜力巨大的有机纳米功能材料 ,其具有以下性质 :(1 )纳米空穴直径稳定且可控 ;(2…     

氨基氮杂环荧光分子改性苯乙烯马来酸酐共聚物的研究

荧光高分子材料 ,由于其独特光学性质 ,成为功能高分子研究热点[1～ 3 ] .一般而言 ,荧光聚合物的合成有两种方法 ,一是首先合成荧光单体 ,然后与其他适宜单体聚合 ,得到荧光聚合物 ,然而荧光单体结构复杂 ,提纯困难 ,难以获得高分子量、成膜性能好的聚合物[4] ;另一种方法是通过官能团的反应 ,用荧光物质对聚合物进行化学改性来制备[5,6] .苯乙烯 马来酸酐共聚物 (ＳＭＡ)是一类成本低廉 ,性能良好的商品化聚合物材料 ,主链中含有具有反应性能的酸酐基团 ,这就使通过化学改性制备荧光聚合物成为可能 .本文通过 2 氨基苯并咪唑 ( 1 ) ,4 …     

氨基封端苯胺五聚体的合成及紫外光谱研究

对苯胺齐聚物的研究论文始于1907年,其结构和电化学性质与聚苯胺相似,易于加工,可用于金属防腐蚀引、化学传感器及催化氧化等方面,从而成为导电高分子的又一研究热点．在苯基/氨基封端(母体)、双苯基封端和双氨基封端中,前两种齐聚物已有大量研究．后一类齐聚物虽可用作电活性聚合物的单体和环氧防腐蚀涂料的固化剂,     

聚苯胺类电致变色材料的研究进展

电致变色材料作为一种绿色环保、节能低碳的新型功能材料,可广泛应用于显示器件、智能窗、节能建筑、国防军事伪装等领域,得到了人们极大的关注。本文综合前人工作,总结了聚苯胺类电致变色材料的最新研究进展,详细介绍了苯胺和取代苯胺均聚物、苯胺和取代苯胺共聚物、聚苯胺衍生物基杂化材料和带有苯胺齐聚物侧链的变色材料的合成及研究现状,特别从材料的分子结构、溶解及变色性能出发,指出了目前聚苯胺类变色材料所存在的问题,并展望了未来改进的方向。     

间氯苯胺的乳液聚合及聚合物链结构表征

聚苯胺以其良好的电化学稳定性和掺杂可逆性 ,成为一类优良的电活性聚合物 [1,2 ] ,但其溶解性差 ,限制了它的加工及应用 .用取代基对聚苯胺的结构进行修饰 ,可有效地提高其加工性能 [3,4 ] ,但有关含吸电子取代基的苯胺衍生物聚合的报道尚少 .Ranger等 [5]指出 ,含强吸电子取代基团的聚苯胺不易用化学氧化聚合方法制备 ,并提出被氧化单体中的 N7和 C4位置必须具有相近的电子自旋密度 ,才能进行“头 -尾”偶联 ,而含强吸电子取代基团的苯胺单体中这两个位置的反应能力是不等价的 ,但可采用与母体共聚的方法可制备含强吸电子取代基 (如— C…     

聚苯胺膜电极在苯胺单体聚合反应中的电催化性能

自从第一个导电高聚物掺碘的聚乙炔问世以来［1］,人们又陆续开发研制了聚 苯胺(PAn)、聚吡咯和聚噻吩等导电高分子材料. 在众多的导电高分子材料中,聚苯胺以其原 料廉价易得,制备方法简便,导电性能优良,耐高温及抗氧化性能良好等优点而成为最具应用 前景的品种之一. 迄今为止,有关聚苯胺的链结构,掺杂反应,以及导电机理等基础理论方面 的研究已有大量的文献和综述报道［2～6］. 这些基础理论的研究为其应用研究奠定 了坚实的基础. 早在60年代,人们就发现,聚苯胺对氧化亚氮分解及丁二烯异构化反应具有独 特的催化作用;同时,聚苯胺具有超出几何表面的活性表面,故可对某些反应具有选择性的催 化作用. 因此,人们开始研究聚苯胺膜电极对某些电极反应的电催化性能［7～12］. 我国科学工作者在这一领域也做了许多有益的工作,如董绍俊等［13］研究了聚苯胺 膜修饰电极对抗坏血酸的电催化氧化,罗维忠等［14］研究了聚苯胺膜电极对Fe(Ⅱ) 和Sb(Ⅲ)的电催化作用. 本文主要讨论了扫描速度、苯胺单体浓度及温度对聚苯胺膜电极在 苯胺单体聚合过程中电催化性能的影响,为利用聚苯胺处理含苯胺废水提供了一定的理论依 据.     

电活性可生物降解材料聚乳酸与苯胺五聚体嵌段共聚物的合成与表征

人体任何一个细微的活动都与生物电有关,外界的刺激、心脏跳动和肌肉收缩、大脑思维等都伴随着生物电的产生和变化,为了寻求一种理想的能够在人体内传导生物电信号的神经传导材料,我们设计合成了既具有电活性,同时又具有良好生物相容性和可生物降解性的材料——聚乳酸（PLA）与苯胺齐聚物的嵌段共聚物,苯胺齐聚物具有和聚苯胺相似的电化学性质,且有更好的溶解性。     

界面层中模型高分子链构象的统计理论

高分子自由链在溶液、熔体或固体中的构象有完整的理论和实验工作 ,已是成熟的知识[1～ 4] .近年来 ,受限大分子构象的探索已成为新的热点[5] .界面是一种最简单的限制 ,将对其附近的高分子产生显著的影响 .除理论家的重视以外 ,界面附近高分子构象问题还与许多应用领域相关 .例如 ,液体高分子的表面张力 ,固体高分子的粘附 ,滑移 ,磨蚀等力学特性 ,甚至它们的光学和电学性质都与界面上的组成和分子构象相关[6] .ｄｅＧｅｎｎｅｓ[7] 最早强调界面附近的分子链构象问题的重要性 .他首先从理论上猜测长链的链端若与界面有强吸引作用 ,则它们…     

末端带有溴甲基基团的柱状树枝化聚酰胺的合成与表征

采用大分子单体的方法合成了一种含大量溴甲基官能团端基,主链和侧链均为聚酰胺的功能化柱状树枝化聚酰胺.氯化亚砜的新活化工艺使整个合成过程不需要保护和去保护的步骤且减少了副反应的产生,从而使得合成和纯化更加简单.产物的结构通过红外和核磁得到了证实.由分子量测试知,聚酰胺的重均分子量(Mw)为5.01×104,分子量分布为2.74.由溶解性测试知,该聚合物能溶解于N,N′-二甲基甲酰胺、N,N′-二甲基乙酰胺、二甲亚砜、1-甲基-2-吡咯烷酮和硫酸等溶剂,溶解性能得到了大大的提高,主要是由于侧链树枝化单元和末端溴甲基存在的缘故.由粘度测试知,该聚酰胺的粘度低,主要是由于侧链树枝化单元的屏蔽效应.该聚合物的热性能也由TGA测试得到了表征,结果表明该聚酰胺具有良好的热性能.由于该聚酰胺外端具有大量的溴甲基基团,它可以作为原子转移自由基聚合反应的引发剂来合成大型的梳形聚合物,另外通过把它外围的溴甲基转化为其它的功能化基团,可以使它应用于其它更广的领域.     

MODIFICATION OF POLYAMIDE 6 WITH POLYAMINOAMIDE-g-POLY(ETHYLENE GLYCOL) VIA HYDROLYTIC POLYMERIZATION

To enhance the impact strength of polyamide 6,hydrolytic polymerization modification by the polyaminoamide-gpoly (ethylene glycol)(PAAEG)derivatives with poly(ethylene glycol)(PEG)molecular weight of 400-10000 was studied. Amide groups of polyaminoamide segments were postulated to form hydrogen bonding with polyamide 6,and hydroxy groups of PAAEG units were expected to react with carboxylic acid groups of polyamide 6 forming copolymers during the polymerization.The improved compatibility in amorphous reg...     

添加剂对双向拉伸尼龙薄膜性能的影响

为提高双向拉伸尼龙薄膜的拉伸性能及薄膜性能,本文研究了不同成核剂、润滑剂及芳香尼龙对高黏度尼龙性能的影响.添加剂改性尼龙6后,冲击性能和断裂伸长率均有不同程度的提高,注塑样品表现为α晶型结构.尼龙6流延骤冷时形成不稳定的α晶型,经过双向拉伸后,转变为稳定的α晶型,在X射线衍射图谱中表现为较强的单峰.改性尼龙制备的双向拉伸薄膜具有较高的力学性能和较低的雾度,综合性能较好;润滑剂Incromold-T具有更好的综合效果.加入少量的半芳香尼龙MXD6,尼龙6结晶能力下降,薄膜光学性提高,但力学强度明显下降.     

DSC Studies on Melting and Crystallization of Polyamide 6/Biopol Blends

Blends obtained from Biopol D600G and polyamide 6 reveal in DSC investigations multiphase structure with a distinct crystalline polyamide 6 phase. Due to rapid crystallization of the polyamide 6 the crystallization of the Biopol D600G is retarded. The grade of crystallization of Biopol D600G is lower in the blends than in the pure state, as calculated from the melting enthalpies. Crystallization of polyamide 6 in the blends is faster and results in increasing of the grade of crystallization of polyamide 6 phase comparing to the unblended component. This revised version was published online in August 2006 with corrections to the Cover Date.     

Isothermal and nonisothermal crystallization kinetics of novel odd-odd polyamide 9 11

A study on isothermal and nonisothermal crystallization kinetics of odd-odd polyamide 9 11 was carried out by differential scanning calorimetry (DSC). The equilibrium melting temperature of polyamide 9 11 was determined to be 199.1 °C. The Avrami equation was adopted to describe isothermal crystallization of polyamide 9 11. Nonisothermal crystallization was analyzed using both the Avrami relation modified by Jeziorny and the equation suggested by Mo. The isothermal and nonisothermal crystallization activation energies of polyamide 9 11 were determined to be −310.9 and −269.0 kJ/mol using the Arrhenius equation and the Kissinger method, respectively.     

Synthesis of saccharide-conjugated polyamides by quasi-living anionic polymerization of a bicyclic lactam

Several well-defined graft copolymers ( 7 ) having a water-soluble natural polysaccharide (dextran) stock and hydrophilic polyamide branches of different molecular weights were synthesized by using a quasi-living anionic polymerization of a bicyclic lactam 1 , namely by the reaction of the acyllactam group in the quasi-living polyamide 2 with the hydroxyl and amino groups in the dextran derivative ( 6 ), of which the reducing end was converted to an amino group. An oligosaccharide-terminated polyamide 3 was also prepared efficiently by similar coupling reaction of the corresponding quasi-living polyamide 2 , with the maltose derivative ( 5 ) having an amino group. © 1994 John Wiley & Sons, Inc.     

The (Co)Polymerization of the Cyclic Diamide 1,6-Diazacyclododecane-7,12-Dione

Abstract

It is demonstrated for the first time that the cyclic diamide 1,6- diazacyclododecane-7,12-dione (c-4) can be polymerized. Polyamide 46 was prepared by thermal or hydrolytic ring-opening polymerization of c-4. c-4 polymerized in the melt to form polyamide 46, containing approximately one-third of the original c-4. Due to possible degradation of c-4 near its melting point, the polyamide 46 formed possibly contained a crosslinked fraction which was insoluble. Therefore, the thermal behavior deviated from that of Stanyl (a commercial polyamide 46 from DSM, The Netherlands). Furthermore, polyamide 46 was prepared by anionic polymerization of c-4 in N-methyl-2-pyrrolidone solution at 202°C. c-4 polymerized with NaH and 1,6-hexamethylene diisocyanate as catalysts. Almost all c-4 was converted to polyamide 46. Due to possible crosslinking, the polyamides had difficulties in dissolving. Furthermore, the thermal behavior of this low molecular-weight polyamide 46 deviated from that of Stanyl, but solid-state postcondensation had a positive effect on the melting point. Then copolyamides of e-caprolactam (CL) and c-4 were prepared by anionic ring-opening copolymerizations. The cyclic monomers polymerized in the melt with lactam magnesium bromide and isophthaloyl-bis-caprolactam as catalysts. It was demonstrated that approximately all c-4 was copolymerized with CL at 180°C. At 200°C only ～ 30% was incorporated. The copolymerization of a maximum of 8.5 mol% c-4 in polyamide 6 showed no effect on the thermal behavior and crystallinity as compared to polyamide 6.     

Morphology and properties of ternary polyamide 6/polyamide 66/elastomer blends

The aim of the work presented is to evaluate the mechanisms and phase interactions in ternary blends based on different polyamides and functionalised elastomers, and to establish a correlation between the morphology controlled by the specific binary interactions, and physical and technological properties, respectively. The properties of the ternary system polyamide 6/polyamide 66/ elastomer depend on the specific blend morphology which is determined mainly by the differences of the surface tension of the components. A phase‐in‐phase structure was observed by microscopic study (AFM) in the ternary polyamide 6/polyamide 66/elastomer blends with maleic anhydride grafted ethene‐octene copolymer, and a “quasi” phase‐in‐phase structure in blends with maleic anhydride grafted ethene‐propene‐diene copolymer as the elastomer phase. An incorporation of polyamide inside of the elastomer particles was observed in the first case due to the difunctionality of polyamide 66. This type of morphology causes an increased elongation at break and toughness of these blends. In comparison to the binary polyamide based blends the ternary blends show an increased elastic modulus, elongation at break and yield stress as well as a high impact strength at low temperatures up to ?20 °C. Copyright © 2003 John Wiley & Sons, Ltd.     

Soluble aromatic polyamide bearing ether linkages: synthesis and characterization

Soluble aromatic polyamide chains were prepared by reacting 4–4′-oxydianiline with isophthaloyl chloride in dimethylacetamide. To quench the HCl produced during the polymerization reaction, a stoichiometric amount of triethylamine was added. The precipitates formed were separated leaving behind clear polyamide resin. Thin and transparent film was obtained by evaporating the solvent and was subjected for Fourier transform infrared (IR), nuclear magnetic resonance (NMR), gel permeation chromatography, thermogravimetric analysis, differential scanning calorimetry, water absorption, and mechanical analyses. The transparent film was found to be soluble in dimethylacetamide, dimethyl sulfoxide, and dimethylformamide. IR and NMR spectroscopic analyses confirmed the structure of the polyamide while the gel permeation chromatography revealed the formation of a high-molecular-weight polymer. Thermogravimetry, differential scanning calorimetry, water absorption, and mechanical testing were also performed to further verify its physical properties. A soluble aromatic polyamide was successfully synthesized by solution polymerization and characterized. The polyamide has film-forming property, and the film is transparent, mechanically strong, and thermally stable.     

The effect of fiber coating on the tensile properties of ionomer-based composites

Asbestos fibers, of the chrysotile variety, were coated with a thin polyamide film by an in situ polycondensation technique. Ionomer-based composites were prepared containing the so-modified asbestos fibers in a random in-plane orientation; results of testing the tensile properties of these asbestos/polyamide/ionomer composites are presented. Parameters investigated comprise the asbestos content in the composite and the polyamide content deposited on asbestos. A significant improvement in the tensile performance was established, especially at the intermediate polyamide content of 3.4 phr. The behavior is discussed in terms of possible interactions between the phases present in the composite material.