共缩聚型可溶性聚酰亚胺的合成与性能

用带有侧基的柔顺性单体3’，3-二甲基-4，4’-二胺基二苯甲烷（MDT），4，4’-二氨基二苯醚（ODA）作为共缩聚二胺单体与3，3’，4，4’-二苯醚四羧酸二酐（0DPA）进行共缩聚反应，合成了一种可溶于N-甲基-2-吡咯烷酮（NMP），N，N＇-二甲基甲酰胺（DMF），N．N＇-二甲基乙酰胺（DMAc）等强极性溶剂的可溶性聚酰亚胺。红外光谱测定表明，在1780．1720和1380cm^-1附近观察到聚酰亚胺特征峰，所得样品在NMP中的特性粘度为1．236～1．278dL／g，玻璃化温度为258～268℃。氮气中的热分解温度在500℃以上。     

新型非对称聚酰亚胺的合成与性能研究

通过对4,4’-双(N-甲基联苯酰亚胺)的单硝化反应、亲核取代反应、水解反应和闭环脱水反应,成功合成了2-邻甲基苯氧基4,4’,5,5’-联苯四甲酸二酐。将这种新型非对称酸酐与4,4’-二氨基二苯醚和对苯二胺进行高温聚合反应制得了非对称聚酰亚胺。聚酰亚胺的特性黏度分别为0.55dL/g和0.89dL/g,它们在有机溶剂中的溶解性能较好,同时具有优良的热稳定性和热氧稳定性。     

含氟和氧膦共缩聚型聚酰亚胺的合成与表征

以水合肼-六水合三氯化铁-活性炭为还原体系, 3, 5 二(三氟甲基)溴苯和二苯基次膦酰氯为原料,经格氏反应、硝化和还原合成了含氟和氧膦的二胺,总收率达 50%。并用FTIR、1HNMR和熔点测试技术对其结构进行了鉴定。该反应具有操作简便,条件温和,收率高易于纯化的优点。然后用常规的二步法,使该二胺和 4, 4′ 二胺基二苯醚与六氟异丙叉基 (3, 4 邻苯二甲酸酐)进行共缩聚,并经化学酰亚胺化制得了共缩聚型聚酰亚胺,收率为 93%。该共缩聚型聚酰亚胺在非质子强极性溶剂中均具有良好的溶解性,玻璃化温度 (Tg)大于 250℃,10%的热分解温度(Td)为 519 7℃。实验表明,氧膦的引入提高了聚酰亚胺的附着力。     

一种主链带侧基的聚酰亚胺薄膜的制备与性能研究

室温下,通过溶液酰亚胺法使3,3’-二甲基-4,4’-二氨基二苯甲烷与3,3’,4,4’-二苯醚四羧酸二酐(ODPA)和3,3’,4,4’-二苯酮四羧酸二酐(BTDA)进行缩聚反应,制备了一种可溶性的主链带侧基的聚酰亚胺。这种聚酰亚胺很容易溶解于诸如NMP、DMAc和DMF等强极性溶剂．通过对其成品膜的可溶性、热稳定性、动态机械性能的初步分析,知道其具有良好的热稳定性和机械性能：热分解温度超过了500,200℃以下其贮能模量超过10^8 Pa。从DMA图中观测到其T2大约为250℃。因此,通过溶液缩聚制得的这种带侧基的聚酰亚胺薄膜具有许多良好的性能,可以被用在诸多方面．     

一种新型磺化聚酰亚胺质子交换膜的合成与表征

质子交换膜是质子交换膜燃料电池膜电极的核心部件之一,它的性能好坏对整个系统的运行起着至关重要的作用．目前在质子交换膜燃料电池中普遍采用的质子交换膜材料是全氟磺酸系列薄膜,这类材料具有较高的质子传导率、化学及机械稳定性,但用于直接甲醇燃料电池（DMFC）时则存在甲醇渗透、导致燃料电池输出性能大大降低的问题     

含氰基聚酰亚胺的合成

通过对3,3′,4,4′-联苯四甲酸二酐(BPDA)进行酯化、溴代、氰基取代、水解以及脱水闭环系列反应,合成了侧链含氰基的新型对称二酐——2,2′-二氰基联苯四甲酸二酐,将其与4,4′-二氨基二苯醚(ODA)通过两步法制备了侧链含氰基的聚酰亚胺(PIDC).PIDC的结构与性能由傅里叶变换红外光谱仪、差示扫描量热仪和热重分析仪表征.结果表明:直接由BPDA和ODA通过两步法制备的聚酰亚胺在大多数有机溶剂中不溶,而室温下PIDC在极性非质子溶剂N-甲基吡咯烷酮、二甲基亚砜、N,N-二甲基甲酰胺、N,N-二甲基乙酰胺中溶解性能良好;氰基的引入使聚酰业胺的玻璃化转变温度由266℃增至303℃,氮气氛围下失重5％的温度提高至523℃.     

含硅聚酰亚胺的合成与性能

含硅聚酰亚胺由于具有可溶性、粘合性、吸湿性以及电绝缘性等方面的优势,近年来逐渐成为聚酰亚胺改性研究的热点。本文主要综述了近年来主链型含硅聚酰亚胺、侧链型含硅聚酰亚胺以及聚酰亚胺含硅无机复合材料的合成方法及其改性性能,并对含硅聚酰亚胺的研究发展进行了展望。     

DABA-BAPP-BPADA共聚聚酰亚胺的合成与性能

用2,2-双[4-(4-氨基苯氧基)苯基]丙烷(BAPP)及3,5-二氨基苯甲酸(DABA)作为二胺,2,2-双[4-(3,4-二羧基苯氧基)苯基]丙烷二酐(BPADA)作为二酐,以N,N-二甲基甲酰胺(DMF)为溶剂,通过常规的两步法,分别经热亚胺化和化学亚胺化过程合成了可溶性共聚聚酰亚胺。用FT-IR对聚合物的结构进行了表征,性能测试采用了溶解性测试、DSC、TGA、拉伸测试和吸水率测试。FT-IR图谱表明,在1 780cm~(-1)、1720 cm~(-1)和740 cm~(-1)左右出现了聚酰亚胺的特征吸收峰。共聚聚酰亚胺在常见有机溶剂中可溶,并且有很好的热稳定性,玻璃化转变温度T_g为226.5℃,在氮气氛中降解起始温度508.5℃,800℃质量保持率为46.5%。共聚聚酰亚胺膜的拉伸强度、拉伸模量、断裂伸长率分别为109.7MPa、2.25GPa和15.2%。     

基于一种含吡啶的氟化二胺的聚酰亚胺合成与性能

对苯二酚依次与2-氯-5-硝基三氟甲苯和2-氯-5-硝基吡啶进行亲核取代反应，还原后制备了一种含吡啶杂环的氟化二胺单体6-{4-[4-氨基-2-(三氟甲基)苯氧基]苯氧基}吡啶-3-胺，并采用两步法将其与二酐聚合，得到4种芳香族聚酰亚胺（PI）。对所得PI的溶解性、耐热稳定性、光学性能、力学性能进行了测试。结果表明，基于4,4’-氧双邻苯二甲酸酐和六氟二酐的PI在常见有机溶剂中均具有良好的溶解性。N2氛围下，这些PI的5%和10%热失重温度分别在548.8～594.2和566.3～609.7℃之间，玻璃化转变温度在226～290℃之间，具有良好的耐热稳定性。这些PI薄膜有较好的光学透明度和力学性能，截止波长在382～438 nm范围内，500 nm处的透过率在52%～78%范围内，拉伸强度为98.3～110.5 MPa，杨氏模量为1.86～2.14 GPa，断裂伸长率为9%～23%。     

PMDA-TDI聚酰亚胺的合成与表征

以均苯四甲酸酐(PMDA)和甲苯二异氰酸酯(TDI)为原料,采用一步法缩聚反应在较低的温度下制备了PMDA-TDI聚酰亚胺。采用傅里叶变换红外光谱(FTIR)、X射线衍射(XRD)、差示扫描量热(DSC)、扫描电镜(SEM)、热重(TG)和耐溶剂性能分析等方法对聚酰亚胺进行表征,探讨不同TDI和PMDA的摩尔比对聚酰亚胺产品结构和性能的影响。结果表明,随着TDI和PMDA的摩尔比增大,产物中的聚脲和TDI二聚体增多,导致聚酰亚胺产品纯度降低,同时玻璃化转变温度降低,耐热性能略有下降。当TDI和PMDA摩尔比为1.1时,合成的聚酰亚胺纯度最高,耐热性能最好,同时该样品具有优异的耐溶剂性能。     

Synthesis and characterization of novel borosiloxane‐containing aromatic copolyimides with excellent thermal stability and low coefficient of thermal expansion

The properties of borosiloxane‐containing copolyimides with borosiloxane in the main chain and in the side chain were studied. Two series of borosiloxane‐containing copolyimides were synthesized by the reaction of 3,3′,4,4′‐biphenyltetracarboxylic dianhydride (s‐BPDA ) and 2,3′,3,4′‐biphenyltetracarboxylic dianhydride (a‐BPDA ) with p ‐phenylenediamine (PDA ), 4,4′‐oxydialinine (4,4′‐ODA ) and different borosiloxane diamine monomers (BSiAs ). The synthesized borosiloxane‐containing copolyimides exhibited better solubility than borosiloxane‐free copolyimides and showed high glass transition temperatures (320–360 °C), excellent thermal stability (570–620 °C for T ₁₀), great elongation at break (10% ? 14%) and a low coefficient of thermal expansion (14–24 ppm °C^?1). More specifically, the copolyimides containing BSiA‐2 formed nano‐scale protrusions and the copolyimides containing BSiA‐1 formed micro‐scale protrusions. The contact angles of the copolyimides increased from 72° for neat copolyimide to 96° for 5% of borosiloxane in the main chain of the copolymer up to 107° for 10% of borosiloxane in the side chain of the copolymer. © 2017 Society of Chemical Industry     

Thermally resistant,mechanically stable,and processable triphenylamine-based hyperbranched copolyimides

A trifunctional, triamine 4-(4-aminophenoxy)-4′,4′′-diamino triphenylamine ( A ) was successfully synthesized by N-arylation in the presence of cesium fluoride, followed by catalytic reduction. A series of aromatic tree-shaped hyperbranched copolyimides (HBPIs, 1–4) was fruitfully synthesized by one-pot polycondensation of a newly synthesized triamine monomer (A), difunctional monomer 4,4′-dianiline, 4,4′-oxydianiline (ODA) and a series of aromatic dianhydride monomers. The appropriate molar ratio of triamine, ODA to the dianhydride monomer B is 1:1:2.5 for HBPIs synthesis using the A₂ A₃ B₅ type copolymerization approach. The synthesized HBPIs exhibited a moderate number-average molecular weight (25,700–28,400 g/mol) and polydispersity in the range 2.6–3.0 as revealed by gel permeation chromatography measurement. The oxidative thermal degradation analyses of the HBPIs showed that the synthesized materials are thermally stable up to 500°C and glass transition temperature in the range 290–302°C. The elongation at break was found in the range 4.8%–8.1% as revealed by tensile measurement. Besides, good thermal stability the HBPIs exhibited excellent flow, appreciable organosolubility, easy processability, and noticeable mechanical stability, thus suggesting their use as thermally resistant, protective coatings for various devices and outdoor environment in the future.     

Synthesis and characterization of novel chain‐extended bismaleimides containing fluorenyl cardo structure

Novel fluorenyl cardo chain‐extended bismaleimides (FCCEBMIs) were synthesized by reacting maleic anhydride with fluorenyl cardo diamine and different dianhydrides. FCCEBMIs were characterized by FT‐IR spectra (FT‐IR), ¹H NMR, and elemental analysis. All FCCEBMI monomers were readily soluble in a variety of organic solvents, such as N‐methyl‐2‐pyrrolidinone, N,N‐dimethyl acetamide, chloroform (CHCl₃), methylene chloride (CH₂Cl₂), dimethyl sulfoxide, and tetrahydrofuran when compared with 9,9‐bis(4‐maleimidophenyl) fluorene. Curing process was investigated by differential scanning calorimetry. Thermal properties of the cured FCCEBMIs were characterized by thermogravimetry analysis, the cured products are stable up to 430°C. The results show that the FCCEBMIs with imide structure improve significantly the solubility of bismaleimide (BMI) in organic solvents without sacrificing thermal properties of cured BMIs. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Synthesis and characterization of poly (ethylene oxide) containing copolyimides for hydrogen purification

Reverse selective membranes comprising poly(ethylene oxide) (PEO) containing copolyimides (PEO-PI) with variations of acid dianhydrides and diamines have been synthesized for hydrogen purification. The reverse selectivity of the membranes decimate the energy required for hydrogen recompression process. Factors including PEO content, PEO molecular weight, and fractional free volume (FFV) that would affect the gas transport performance have been investigated and elucidated in terms of degree of crystallinity, phase separation in the PEO domain as well as inter-penetration between the hard and soft segments. In mixed gas tests of CO₂ and H₂ mixtures, a highly condensable CO₂ out compete H₂ for the sorption sites in hard segment and diminishes H₂ permeability. Thus the CO₂/H₂ selectivity in the mixed gas tests is much higher than that in pure gas tests. Mixed gas permeation tests at 35 °C and 2atm show that the best reverse selective membranes have a CO₂ permeability of 179.3 Barrers and a CO₂/H₂ permselectivity of 22.7. The physical properties of PEO-PIs have also been characterized by FTIR, DSC, GPC, WAXS, AFM and tensile strain tests.     

可溶性BAPP-MDA-ODPA共聚聚酰亚胺的合成与性能

用2,2-双[4-(4-氨基苯氧基)苯基]丙烷(BAPP)和4,4′-二氨基二苯甲烷(MDA)作为二胺,3,3,′4,4′-二苯醚四羧酸二酐(ODPA)作为二酐,以N,N-二甲基甲酰胺(DMF)为溶剂,通过常规的两步法,分别经热亚胺化和化学亚胺化过程合成了可溶性共聚聚酰亚胺。用FT-IR对聚合物的结构进行了表征,FT-IR测试结果表明在1 780 cm-1、1 720 cm-1和725 cm-1左右出现了聚酰亚胺的特征吸收峰。采用溶解性测试、DSC、TGA、拉伸测试和吸水率测试对产物的性能进行了测试。共聚聚酰亚胺在常见有机溶剂中可溶,并且有很好的热稳定性,在氮气氛中,起始降解温度超过500℃,800℃质量保持率为58.2%。共聚聚酰亚胺膜的拉伸强度、拉伸模量、断裂伸长率分别为103.5 MPa,2.36 GPa和11.7%。同时共聚聚酰亚胺膜还有很低的吸水率,为0.87%。     

共缩聚型可溶性耐高温聚芳酰胺合成与表征

采用二胺1，2—二氢—2—(4—氨基苯基)-4—[4—(4—氨基苯氧基)—苯基卜二氮杂萘—1—酮(二胺A)、对苯二胺为共缩聚二胺单体，与对苯二甲酸在Yamazaki膦酰化法聚合体系中，选择直接缩聚法，成功得到高分子量的聚芳酰胺，其特性粘数为0．96～1．44dL／g。以傅里叶变换红外光谱、核磁共振氢谱等分析手段研究了聚合物的结构，利用差示扫描量热法、热失重分析研究了聚合物的耐热性能。结果表明，该系列聚合物具有高的玻璃化转变温度(约为300℃)，氮气氛中5％热失重温度在450℃以上；当二胺A与对苯二胺的物质的量比例为10：0—5：5时，所得聚合物溶解于强极性溶剂。同时，系统研究了影响聚合物特性粘数的诸多因素，从而确定了最佳工艺条件。     

含噁唑环支链的苯氧型共聚聚酰亚胺的合成与表征

以3,5-二硝基苯甲酰氯和邻氨基苯酚为原料合成了含苯并噁唑基团的二胺,然后将其与二氨基二苯醚(ODA)和二苯醚四甲酸二酐(ODPA)进行常温共聚合成聚酰胺酸,最后采用两步法合成了含苯并噁唑支链的可溶性聚酰亚胺(PI)。采用红外光谱(FT-IR)、差示扫描量热法(DSC)和热重分析(TGA)等测试手段分析了该PI的结构、热性能和在各溶剂中的溶解性能。实验结果表明,经300℃热处理1h后,聚酰胺酸转化为酰亚胺化比较完全;引入苯并噁唑支链基团可以提高PI的耐热性,其玻璃化转变温度(Tg)在300℃左右,初始热分解温度为552.5℃;该PI在强极性溶剂中溶解性能良好,但不溶于一般的极性溶剂中,说明其在提高加工性能的同时仍能保持耐一般溶剂的性能。     

Synthesis and characterization of benzimidazole‐based low CTE block copolyimides

A series of block and random copolyimide films were synthesized from various molar ratios of two diamines, rigid 2‐(4‐aminophenyl)‐5‐aminobenzimidazole (APBI) and flexible 4,4′‐oxydianiline (ODA) by polycondensation with dianhydride 3,3′,4,4′‐biphenyltetracarboxylic dianhydride. The contents of APBI ranged from 10 to 60 mol % in copolyimides. The copolyimide films obtained by thermal imidization of poly(amic acid) solutions, were characterized by TMA, DMA, TGA, DSC, wide‐angle X‐ray diffraction, FTIR, tensile testing, water uptake (WU), and dielectric constant measurements. Rigid heterocyclic diamine APBI with interchain hydrogen bonding capability, led to low coefficient of thermal expansion (CTE), high T_g, high thermal stability and better mechanical properties. Increasing the APBI mol % caused a gradual decrease in the CTE and increase in T_g, thermal stability and tensile strength properties of the copolyimides films. Moreover, significantly enhanced thermal and mechanical properties of the block copolyimides were also found as compared to random copolyimides. The block copolyimide with APBI content of 60 mol %, achieved excellent properties, that is, a low CTE (4.7 ppm/K), a high T_g at 377°C, 5% weight loss at 562°C and a tensile strength at 198 MPa. This can be interpreted because of comparatively higher degree of molecular orientation in block copolyimides. These copolyimides also exhibited better dielectric constant and WU. This combination of properties makes them attractive candidates for base film materials in future microelectronics. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Synthesis,characterization, and properties of new siloxane grafted copolyimides

Three new siloxane containing grafted copolyimides have been prepared by one‐pot solution imidization technique. The polymers are made by the reaction of 4,4′‐(4,4′‐isopropylidenediphenoxy)bis(phthalic anhydride) (BPADA) with commercially available diamine 4,4′‐oxydianiline (ODA) with variation of silicon containing diamine, namely 3,5‐diaminobenzoate terminated polydimethylsiloxane (DBPDMS), as a comonomer to 10, 20, and 30 wt %. The films of the polymers were prepared by casting the polymer solution in dichloromethane. The polymers have been well‐characterized by GPC, IR, and NMR techniques. Thermal stabilities and decomposition behavior of the copolyimides were studied by DSC and TGA. The water contact angle values of the films indicate hydrophobic nature of the polymers. Thermal, flame retardant, mechanical, and surface properties of these polymers have been compared with the homopolyimide and with polyimides where polysiloxane is incorporated in the main chain. DSC revealed melting of the grafted siloxane chain at sub‐ambient temperature and a glass transition corresponding to the main polymer chain above 200°C. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Gas permeability and permselectivity of photochemically crosslinked copolyimides

A series of copolyimides were prepared from 2,4,6-trimethyl-1,3-phenylenediamines (3MPDA), 3,3′,4,4′-benzophenone tetracarboxyl dianhydride (BTDA), and pyromellitic dianhydride (PMDA). Modification of the copolyimides by ultraviolet irradiation were carried out. Gas permeabilities of H₂, O₂, and N₂ through the copolyimides and photochemically crosslinked copolyimides were measured at temperatures from 30 to 90°C. The relationships between gas permeabilities and temperature are in agreement with the Arrhenius equation. The structure of photochemically crosslinked copolyimides were characterized by Fourier transform infrared and gel measurement methods. Linear relationships between both log P and E_p and the volume fraction of PMDA–3MPDA exist. Photochemically crosslinking modification result in a decrease in gas permeability and an increase in E_p and α(H₂/N₂) for all the copolyimides. For H₂/N₂ separation, photochemically crosslinked copolyimides are of higher gas permeabilities and permselectivities simultaneously than normal polyimides. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 521–526, 1999