吡啶桥联的聚酰亚胺的合成与性能研究

以3,4-二甲基苯乙酮与3,5-双(三氟甲基)苯甲醛为原料,通过Chichibabin反应制备了吡啶桥联的四甲基化合物,该化合物再经氧化、脱水反应制备了主链含有吡啶环、侧链带有双三氟甲基取代苯侧基的新型含氟芳香族二酐单体,2,6双(3′,4′-二羧基苯基)-4-(3″-,5″-双三氟甲基苯基)吡啶二酐(6FDAPA).FT IR、NMR、质谱以及元素分析等测试结果表明,6FDAPA的结构与预期的相符.利用6FDAPA与另外一种不含氟的二酐单体2,6双(3′,4′二羧基苯基)4苯基吡啶二酐(DAPA)分别与含氟二胺单体,1,4双(2三氟甲基4氨基苯氧基)苯(6FAPB)通过两步热亚胺化法制备了两种聚酰亚胺(PI)薄膜.测试结果表明,6FDAPA6FAPB(PI2)与DAPA6FAPB(PI1)相比具有相近的耐热性能,玻璃化转变温度为280℃,起始热分解温度为580℃、700℃时的重量保持率64.5%.同时PI2具有更为优良的透光性,紫外可见光谱(UV Vis)测试表明,PI2与PI1薄膜在450nm处的透光率分别为85.7%与69.4%.     

含氟苯乙炔苯胺封端聚酰亚胺的合成与性能研究

设计并合成了一种含氟苯乙炔苯胺封端剂4-苯乙炔基-3-三氟甲基苯胺(3FPA),使用3FPA与4,4′-(六氟异丙基)双邻苯二甲酸二酐(6FDA)和对苯二胺(p-PDA)制备了计算分子量为5000的聚酰亚胺树脂3FPA-PI-50,并对树脂溶液、树脂模塑粉和树脂模压件的制备与性能进行了研究,实验结果表明3FPA-PI-50树脂溶液具有良好的储存稳定性,成型后树脂具有优异的热性能和热氧化稳定性,后固化后树脂玻璃化转变温度为404℃,5%热失重温度大于530℃.此外树脂具有低的介电常数和吸水率.     

一种主链含光敏基团聚酰亚胺的合成与表征

通过4,4′-二羟乙基查尔酮与1,2,4-苯三酸酐酰氯反应,得到了一种新型的主链含查尔酮的二酐单体,通过二酐和2,2-双(3(-氨基-4(-羟基苯基)六氟丙烷缩聚并高温亚胺化,得到了一种新型的主链含查尔酮,侧链含羟基的光敏聚酰亚胺,并通过1H-NMR、FTIR、GPC及热分析表征了得到的聚酰亚胺的结构和热性能.这种聚酰亚胺在极性溶剂中具有较好的溶解性,并具有较高的热稳定性,在紫外光照射下,能进行[2+2]的环加成反应.     

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.     

新型含酯基结构的具有低线膨胀系数和吸水性的聚酰亚胺的合成

将2种主链中含有酯基结构的二胺单体:二(4-氨基苯基)对苯二甲酸酯(BPTP)和4-氨基苯基-4-氨基对苯甲酸酯(APAB),与几种常见的酸酐聚合,合成了一系列主链中含有酯基结构的新型聚酰亚胺膜材料.结果表明,所制备的聚酰亚胺薄膜表现出优良的热稳定性、机械性能和低吸水性,其中聚合物的表观玻璃化转变温度高达526℃,在空气和N2气气氛下5%的热失重温度分别在498和507℃以上,表明薄膜具有非常优异的热性能.由于聚合物主链中引入酯基结构而表现出低的线膨胀系数和吸水率.     

有机可溶性含氟不对称聚酰胺酰亚胺的合成与性能

采用不对称联苯二酐单体2,3,3′,4′-联苯四甲酸二酐(a-BPDA)与3-氨基-2,4,5-三氟苯甲酸(3FAB)反应制备了一种新型不对称二酸化合物2,3,3′,4′-联苯四甲酸-N,N′-双(3-羧基-2,5,6-三氟苯基)二酰亚胺 (a-BPFDI).以此两种酸为原料、N-甲基-2-吡咯烷酮(NMP)为溶剂、亚磷酸三苯酯(TPP)与吡啶为缩合剂、氯化钙为催化剂,通过Yamazaki-Higashi反应,直接与3种芳香族二胺单体反应制得一系列聚酰胺酰亚胺(PAI).研究表明:PAI材料在极性非质子性溶剂中具有优良的溶解性能,其薄膜的玻璃化转变温度超过250 ℃,氮气中起始热分解温度超过410 ℃.此外,PAI薄膜还具有良好的力学性能以及介电性能.厚度为10 μm左右的PAI薄膜在可见光区(400～700 nm)的透光率达到或超过80%.     

主链含邻位取代单元及吡啶环聚酰亚胺的合成与性能

以o-羟基苯乙酮、对氯硝基苯和苯甲醛为原料,通过亲核取代反应、改进的Chichibabin反应以及水合肼催化还原合成了一种新型含邻位取代单元及吡啶环的芳香二胺4-苯基-2,6-双[3-(4-氨基苯氧基)苯基]吡啶(o,p-PAPP).以N,N-二甲基甲酰胺(DMF)为溶剂,将o,p-PAPP分别与3,3',4,4'-二苯醚四羧酸二酐(ODPA)、2,2-双[4-(3,4-二羧基苯氧基)苯基]丙烷二酐(BPADA)、3,3',4,4'-二苯酮四甲酸二酐(BTDA)及均苯四甲酸二酐(PMDA)通过常规的两步法,合成了4种聚酰亚胺.用FTIR、DSC、TGA、XRD、溶解性测试、UV-Vis和荧光光谱对聚合物的结构和性能进行了表征.FTIR结果表明,所得的聚合物在1780,1720和1380cm-1左右出现了聚酰亚胺的特征吸收峰.实验所得的PI能很好地溶解于常见有机溶剂(如DMF,DMAC,DMSO,NMP,THF,CHCl3),在氮气氛中,PI的10%失重温度(T10)为444.2～467.5℃,800℃时的残余质量(Rw)为49.6%～58.3%.同时PI分子主链中的吡啶环结构使其具有良好的紫外光吸收性能,经HCl质子化后,在460 nm附近出现非常强的荧光发射峰.     

新型含磷和氟聚芳醚的制备、表征及性能

通过分子设计, 成功合成了一种含有三苯基膦结构的二氟单体--4,4’-二氟二苯苯磷氧(BFPPO). 在碱催化条件下, BFPPO与2-双-(4-羟苯基)六氟丙烷(六氟双酚A)缩聚得到一种新型含三苯基膦结构的聚芳醚材料(6F-PAEPO). 使用FTIR,1H NMR, 31P NMR, 和16F NMR等表征手段确定了聚合物的结构, 聚合物表现出良好的热稳定性、有机可溶性、机械性能和光透过性能, 其中聚合物的玻璃化转变温度高达211℃, 空气气氛和氮气气氛下5%热失重温度分别为512℃和523℃, 聚合物薄膜的最大光透过率超过80%. 尤其, 聚合物由于主链中三苯基磷氧结构的存在, 表现出了优异的阻燃性能, 有限氧指数(LOI)达到39.9%.     

共聚聚酰亚胺膜材料的合成及其气体渗透性能研究

以2,2′-双(3,4-二羧基苯基)六氟丙烷二酐(6FDA)作为二酐单体,1,3-苯二胺(mPDA)和2,6-二氨基甲苯(2,6-DAT)为二胺单体,采用溶液共缩聚方法合成了一系列新型共聚聚酰亚胺(6FDA-2,6-DAT/mPDA),该类聚合物均能溶于DMF、DMAc、NMP等极性非质子溶剂中,具有较好的成膜性.测试了H2、N2、O2、CH4、CO25种气体在6FDA-2,6-DAT/mPDA共聚聚酰亚胺致密膜中的渗透性能.结果显示,该系列共聚物具有优异的分离性能.在35℃,0.2 MPa下,H2/N2、O2/N2、CO2/CH4的分离性能均接近或突破Robeson上限.     

主链含有三芳基均三嗪环的可溶性双苯基芴基聚芳醚的合成与性能

以含均三嗪环结构的双氟单体2,4-二(4-氟苯基)-6-苯基-1,3,5-三嗪(BFPT)与4,4’-联苯二酚(BP)和9,9-二(4-羟基苯基)芴(BHF)为共聚单体,经溶液亲核取代逐步聚合,合成了一系列主链含三芳基均三嗪环结构和双苯基芴结构线性聚芳醚(PEPs).反应过程经优化,得到的聚合物数均分子量高达6.3×104.采用元素分析、FTIR、NMR和H-H gCOSY等对聚合物结构进行表征,并对聚合物进行溶解性、示差扫描量热(DSC)、动态力学性能(DMA)、热失重(TGA)、机械性能等测试.由于双苯基芴基团的存在,聚合物的溶解性得到明显改善.当双苯基芴结构单元含量高于20%时,聚合物可溶于N-甲基吡咯烷酮(NMP)、氯仿(CHCl3)、四氯乙烷(C2H2Cl4)、和吡啶(pyridine)等极性溶剂中,同时保持了优异的耐热性.聚合物的玻璃化转变温度Tg由DSC测得在269~307℃之间,由DMA测得在269~291℃之间,且随着主链中双苯基芴结构的增加而升高.N2气氛下,PEPs的5%热失重温度超过544℃,800℃残碳率大于48%.     

HETEROAROMATIC POLYMERS — HIGH TEMPERATURE POLYPYRROLONES DERIVED FROM 2,6-BIS(3'',4''-DIAMINOPHENYL)-4-BIPHENYLPYRIDINE AND VARIOUS AROMATIC DIANHYDRIDES

A new type of aromatic tetraarnine containing biphenyl moiety in the side chain was synthesized via a modified Chichibabin＇s reaction. 3-Nitro-4-acetamidoacetophenone was reacted with 4-phenyl benzaldehyde in the presence of ammonium acetate to obtain 2,6-bis（3＇,4＇-diaminophenyl）-4-biphenyl pyridine （DPPA）. A series of polypyrrolones （PPys） were prepared using tetraamine and various aromatic dianhydrides via a two-step cyclization procedure. All the PPys show excellent high temperature stabilities with the initial decomposition temperatures of 530-549℃ and residual weight ratio of 49%-80% at 750℃ in nitrogen. The polymers exhibit no apparent glass transition temperatures （Tgs） except PPy-1 （Tg= 327℃）, which is derived from tetraamine DPPA and 2,2-bis[4-（3＇,4＇-dicarboxyphenoxy）-phenyl]propane dianhydride （BPADA）. In addition, the polymers have acceptable mechanical properties with the tensile strength of 65-94 MPa. The PPy films show excellent hydrolysis-resistance in alkaline aqueous medium and could maintain most of the properties even after boiling in 10% aqueous sodium hydroxide solution for a week.     

Synthesis and characterization of new polybenzimidazopyrrolones derived from pyridine‐bridged aromatic tetraamines and dianhydrides

A series of new polybenzimidazopyrrolones (polypyrrolone, PPy) were synthesized by polycondensation of pyridine‐bridged aromatic tetraamines, including 2,6‐bis (3′,4′‐diaminophenyl)‐4‐phenylpyridine and 2,6‐bis(3′,4′‐ diaminophenyl)‐4‐(3″‐trifluoromethyl)phenyl pyridine, with various aromatic dianhydrides. Experimental results indicated that the PPys, multiaromatic conjugated and semiladder polymers, showed good thermal stabilities with thermal‐decomposition temperatures of about 500 °C and residual weight retention at 750 °C as high as 84%. PPy films could be obtained by casting the precursor solution, poly(amide amino acid) on glass substrate, followed by thermal dehydrating at elevated temperatures. The polymer films exhibited excellent alkaline hydrolysis resistance, which retained their original shapes and toughness after boiling 7 days in 10% sodium hydroxide solution. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 1845–1856, 2004     

ORGANO-SOLUBLE FLUORINATED POLYIMIDES DERIVED FROM a,a-BIS(4-AMINO-3,5- DIMETHYLPHENYL)-4′-FLUOROPHENYL METHANE AND VARIOUS AROMATIC DIANHYDRIDES

 Organo-soluble fluorinated polyimides were synthesized by the polycondensation of a new aromatic diamine -bis(4-amino-3,5-dimethylphenyl)-4′-fluorophenyl methane with several aromatic dianhydrides. The one-step polymerization procedure was conducted at 180℃ in m-cresol, producing the polyimides with inherent viscosities of 0.680.76 dL•g1. The polyimides could be soluble not only in polar aprotic solvents, such as N-methyl-2-pyrrolidinone, and N,N-dimethylacetamide, but also in common organic solvents, such as chloroform, cyclopentanone, m-cresol and so on. The polyimide films show excellent transparency with the UV-Vis cut-off lengths of 310360 nm and light transmittances of higher than 80% in the visible region. In addition, the polyimides exhibit good thermal stability with an initial decomposition temperature (Td) higher than 530℃ and have more than 60% of residual weight retentions at 700℃.     

含二氮杂萘酮结构溶致液晶聚芳酰胺的合成及性能

以Kevlar(R)(其结构为聚对苯二甲酰对苯二胺,PPTA)为代表的聚芳酰胺,分子链排列非常规整,分子键具有很强的极性和分子间氢键作用,这一结构特点赋予它们良好的热稳定性,优秀的耐化学性能,独特的溶致液晶性和优异的机械性能.但是另一方面也造成了它们在常用有机溶剂中有限的溶解性和高的熔融温度,因而限制了它们的生产和应用[1～3].     

SYNTHESIS AND CHARACTERIZATION OF ORGANO-SOLUBLE FLUORINATED POLYIMIDES FROM 4,4′-BIS(3-AMINO-5-TRIFLUOROMETHYLPHENOXY)-BIPHENYL AND VARIOUS AROMATIC DIANHYDRIDES

An aromatic diamine monomer, 4,4′-bis(3-amino-5-trifluoromethyl phenoxy)-biphenyl (TFBPDA), was synthesized via the nucleophilic displacement reaction of 3,5-dinitrobenzotrifluoride and 4,4′-biphenol. The monomer was reacted with various aromatic dianhydrides via the high temperature polycondensation procedure to provide a series of polyimides. The polyimides, PI-1 to PI-4, show good solubility not only in aprotic solvents, such as N-methyl-2-pyrrolidinone and N,N-dimethylacetamide, but also in many common solvents, such as m-cresol, chloroform and cyclopentanone. PI-4, derived from 4,4′-(hexafluoroisopropylidene)diphthalic anhydride and TFBPDA, was even soluble in toluene. Moreover, PI films exhibit good thermal stability, outstanding transparency in the visible light region and acceptable mechanical and electrical properties. The excellent combined properties of the polyimides make them as a good candidate for fabricating microelectronics.     

Preparation of Meltable Aromatic Polyimides and Their Adhesive Properties

A series of molecular-weight-controlled aromatic polyimides based on 4,4′-oxydiphthalic anhydride (ODPA), 1,4-bis(4-amino-2-trifluoromethylphenoxy)benzene (6FAPB) and 3,3′-diaminodiphenylsulfone (3,3′-DDS) were synthesized in the presence of phthalic anhydride (PA) as an end-capping agent. The effect of molecular weight on the solubility, melt viscosity, thermal and mechanical properties of the polyimides was investigated. Experimental results demonstrated that the polyimides exhibit good solubility in most polar aprotic solvents and in some common organic solvents, such as DMSO and THF. Homogeneous and stable polyimide solutions with solid contents as high as 40–45 wt% were prepared. High-quality polyimide films were obtained by casting the polyimide solutions onto glass plates and baking them at a relatively low temperature. The polyimide films exhibited outstanding thermal and mechanical properties. The rheological behavior of the polyimides depends on their molecular weight. The adhesive properties of polyimide films bonded to stainless steel at different temperatures were evaluated by the lap shear strength (LSS) test. The polyimides with moderate molecular weight exhibited better adhesive properties. The LSS of polyimide films at ambient and elevated temperatures increased with increasing bonding temperature, which is attributed to the better flow and wetting of the polymer melts during the bonding process.     

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 ℃.     

新型可溶性聚芳酰胺及其共聚物的合成与性能研究

采用新型二胺 1,2 二氢 2 (4 氨基苯基 ) 4 [4 (4 氨基苯氧基 ) 苯基 ] 二氮杂萘 1 酮与对苯二甲酸、间苯二甲酸、萘二酸进行均聚或共聚 ,所得聚芳酰胺的Tg 均高于 30 0℃ ,且易溶于非质子极性溶剂中 ,聚合物的特性粘数为 1 2 6～ 1 5 1dL g(2 5℃ ,NMP) ,拉伸强度为 6 2～ 89MPa ,断裂伸长率为 5 %～ 9% ,拉伸模量为 2 2～ 2 9GPa ,电阻系数为 10 1 4 ～ 10 1 6     

含1,3,5-三嗪芳香二酸及其可溶性聚芳酰胺的合成

以2,4-二氯-6-苯基-1,3,5-三嗪为原料,通过傅克和氧化反应制备了一种新型芳香二酸2,4-二(4-甲酸基苯基)-6-芳基-1,3,5-三嗪(PTDA),并采用1H-NMR,FTIR,MS和元素分析等对其结构进行了表征.利用正交试验,重点考察了氧化反应条件对产率的影响,结果表明反应温度为25℃、反应时间为8 h、HAc与H2SO4摩尔比为10∶1、CrO3与PTDA配比为4∶1时,氧化产率最高,达81.3%.以PTDA和间苯二胺(BD)为原料,制备了新型含1,3,5-三嗪聚芳酰胺PPA,其特性黏数为0.49 dL/g.该聚酰胺表现出较好的溶解性能以及优异的热稳定性和机械性能,室温下可溶于N-甲基-2-吡咯烷酮、N,N-二甲基乙酰胺等溶剂中,由其溶液可制得透明薄膜;玻璃化转变温度达315℃,氮气中起始分解温度T5%为493℃,700℃下残炭率高达59%;薄膜的拉伸强度为82 MPa,断裂伸长率在8.2%,起始模量为2.3 GPa.