共缩聚聚酰胺酸和聚酰亚胺的微波辐射合成研究

在N,N′-二甲基甲酰胺(DMF)溶剂中,选用3,3,′4,4′-二苯酮四羧酸二酐(BTDA)、均苯四甲酸酐(PMDA)和4,4′-二氨基二苯醚(ODA)为单体,微波辐射低温溶液缩聚合成一种共缩聚聚酰亚胺的前驱体聚酰胺酸(PAA),然后亚胺化脱水环化生成共缩聚聚酰亚胺(PI)。通过特性黏数([η])、红外光谱(FT-IR)和热重分析(TGA)对聚合物进行了结构表征和性能测试。结果表明,微波辐射溶液聚合能够提高PAA的特性黏数及产率,微波的引入大大缩短了反应时间;IR表明,在1778 cm-1和1723 cm-1处观察到聚酰亚胺特征峰;TG表明,PI在氮气中535℃左右开始降解,10%热失重温度(Td10%)为587℃。     

微波辐射合成聚酰胺酸和聚酰亚胺的研究

在N,N’-二甲基甲酰胺溶剂中,以均苯四甲酸酐和3,3’,4,4’-二苯酮四羧酸二酐为二酐单体,4,4’-二氨基二苯醚和4,4’-二氨基二苯甲烷为二胺单体,采用微波辐射低温溶液共缩聚,合成了聚酰胺酸(PAA)预聚体,然后亚胺化脱水、环化,生成共缩聚聚酰亚胺(PI)。通过红外光谱(FT-IR)、特性粘度[η]和热重分析(TG)等对聚合物进行了一系列的结构表征和性能测试。结果表明,微波辐射溶液聚合能够提高PAA的特性粘数及产率,微波的引入大大缩短了反应时间;FT-IR表明,在1 775 cm-1和1 724 cm-1处观察到聚酰亚胺特征峰;TG表明,PI的5%热失重温度(Td5%)为477℃,10%热失重温度(Td10%)为553℃。     

化学亚胺化法合成三元共聚聚酰亚胺

以N,N-二甲基甲酰胺为溶剂,用3,3′,4,4′-二苯酮四酸二酐(BTDA)、2,2-双[4-(4-氨基苯氧基)苯基]丙烷(BAPP)和4,4′-二氨基二苯砜(DDS)合成3种聚酰亚胺(PI)。先用BAPP和/或DDS与BTDA反应生成一系列聚酰胺酸(PAA),然后将得到的PAA化学亚胺化制备相应的PI。用傅里叶变换红外光谱(FTIR)仪、核磁共振仪和黏度计等表征了聚合物的结构和性能。FTIR谱图中1780,1720,725 cm~(-1)附近出现了PI的特征吸收峰。制备的PI有很好的热稳定性,N_2气氛中低于500℃没有明显的降解。     

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%。     

PAPP/ODA共聚聚酰亚胺的制备与性能

以4–苯基–2,6–双[4–(4–氨基苯氧基)苯基]吡啶和4,4′–二氨基二苯醚为二胺单体,3,3′,4,4′–二苯酮四羧酸二酐为二酐单体,N–甲基–2–吡咯烷酮为溶剂,通过一次加料,得到共聚聚酰亚胺。用傅立叶变换红外光谱仪、差示扫描量热仪、热重分析仪、X射线衍射仪、溶解性测试等对共聚聚酰亚胺的结构和性能进行了表征。研究结果表明,所得聚合物在1 780,1 723,1 380 cm-1左右出现了聚酰亚胺的特征吸收峰,实验所得的聚酰亚胺能很好地溶解在常见有机溶剂中,玻璃化转变温度为246℃,氮气气氛中,10%的热失重温度为505℃,800℃的残余率为48%。     

三元共聚无氟芳香族透明聚酰亚胺合成及性能

以N,N-二甲基乙酰胺为溶剂,用芳香族二胺4,4′-二氨基二苯醚(ODA)与不同比例的2个芳香族二酐4,4′-联苯四甲酸二酐(BPDA)、双酚A型二醚二酐(BPADA)制备三元共聚无氟芳香族透明聚酰亚胺(PI)薄膜。用傅里叶变换红外光谱仪(FTIR)表征PI结构,用差示扫描量热仪(DSC)、热重分析仪(TG)、阻抗分析仪、紫外-可见分光光度仪(UV-VIS)研究PI薄膜的热性能、介电性能和透光率。结果表明：三元共聚PI薄膜玻璃化转变温度高于210.0℃;热失重5%的温度高于480.0℃;在可见光范围内透明性良好,PI薄膜在465 nm处透光率均超过80.0%,最高可达85.5%;相对介电常数为1.728 1～2.987 2,介电损耗为0.002 9～0.014 3。     

2L-FCCL用聚酰亚胺复合膜的制备与性能

采用2,2′-双[4-(4-氨基苯氧基)苯基]丙烷(BAPP)、4,4′-二氨基二苯醚(ODA)和3,3′,4,4′-二苯酮四酸二酐(BTDA)合成BAPP/ODA/BTDA型聚酰亚胺(PI)的前驱体聚酰胺酸(PAA)溶液,将该溶液涂覆于3,3′,4,4′-联苯四甲酸二酐(BPDA)/ODA型PI基膜上,通过去溶剂和热亚胺化制备PI复合膜,将复合膜的热塑面与铜箔复合,热压制得二层挠性覆铜板(2L-FCCL)。研究了BAPP/ODA/BTDA型PI、BPDA/ODA型PI、PI复合膜及2L-FCCL的性能。结果表明:BAPP/ODA/BTDA型PI薄膜的玻璃化转变温度为238℃,耐热性能优异,PI复合膜在280℃,15MPa下与铜箔层压50~60min制得的2F-FCCL剥离强度大于0.8N/mm,且经360℃焊锡浴测试未分层、未起泡,耐热性能和剥离强度均满足工业要求。     

含砜基聚酰亚胺的合成及其中空纤维膜的制备（英文）

以4,4'-(六氟异丙烯)二酞酸酐(6FDA)与4,4'-双(4-氨基苯氧基)二苯砜(BAPS)为反应单体,以N-甲基-2-吡咯烷酮(NMP)为溶剂,合成了聚酰胺酸(PAA),将PAA溶液采用流延成膜的方法制备成薄膜;另外,将PAA溶液采用干-湿法纺丝工艺制得PAA中空纤维膜,再将PAA薄膜及其中空纤维膜在300℃左右的高温热环化制得6FDA-BAPS型聚酰亚胺(PI)膜。研究了6FDABAPS型PI及其中空纤维膜的结构与性能。结果表明:所合成的6FDA-BAPS型PI为目标产物,其在NNP、N,N-二甲基乙酰胺、四氢呋喃中具有良好的溶解性能。6FDABAPS型PI中空纤维膜外皮层致密、支撑层疏松多孔,该中空纤维膜具有较高的热学性能和力学性能,在氮气氛围中热失重5%的温度为511℃,断裂强度为26.5 MPa。     

化学亚胺化合成含吡啶环共聚聚酰亚胺

用2,2-双[4-（4-氨基苯氧基）苯基]丙烷（BAPP）和4-苯基-2,6-双（4．氨基苯基）吡啶（PBAP）作为二胺,3,3’,4,4＇-二苯酮四酸二酐（BTDA）作为二酐,以N,N-二甲基甲酰胺（DMF）为溶剂,合成了3种聚酰亚胺。先用BAPP和PBAP同BTDA反应生成一系列聚酰胺酸（PAA）,然后将得到的PAA用化学亚胺化制备相应的聚酰亚胺。用FT-IR、^1H—NMR、粘度测试、溶解性测试和TGA对聚合物的结构和性能进行了表征。结果表明,FT—IR测试在1780cm^-1、1720cm^-1和725cm^-1左右出现了聚酰亚胺的特征吸收峰,所得聚酰胺酸的特性粘数为0．32～0．46dL／g,大部分聚酰亚胺在常见有机溶剂NMP中可溶,它们有很好的热稳定性,氮气氛中,在500℃以前没有明显的降解。     

静电纺聚酰亚胺非织造布的制备与表征

以N,N-二甲基乙酰胺(DMAc)为溶剂,3,3',4,4'-二苯醚四甲酸二酐(ODPA)和4,4'-二氨基二苯醚(ODA)为单体,利用高压静电纺丝技术,制备了聚酰胺酸(PAA)和聚酰亚胺(PI)非织造布,并采用扫描电镜(SEM)对PAA及PI非织造布的表面形态进行表征,研究了PI非织造布的力学性能。结果表明:经300℃热亚胺化处理得到的PI非织造布,纤维平均直径减小到500nm以下,纤维的带状形貌与PAA明显不同,并且出现了收缩、弯曲等现象。静电纺丝法制得的PI非织造布的力学性能仍然比较优越。     

Preparation and characterization of new optically active poly(amide‐imide)s derived from N,N‐(4,4′‐Oxydiphthaloyl)‐bis‐(s)‐(+)‐valine diacid chloride and aromatic diamines

4,4′‐Oxydiphthalic anhydride (1) was reacted with (s)‐(+)‐valine (2) in acetic acid and the resulting imide‐acid 3 was obtained in high yield. This compound 3 was converted to diacid chloride 4 by reaction with excess amount of thionyl chloride. The polycondensation reaction of diacid chloride 4 with several aromatic diamines such as 4,4′‐sulfonyldianiline (5a), 4,4′‐diaminodiphenyl methane (5b), 4,4′‐diaminodiphenylether (5c), p‐phenylenediamine (5d), m‐phenylenediamine (5e), and 4,4′‐diaminobiphenyl (5f) was performed by two conventional methods: low temperature solution polycondensation and a short period reflux conditions. To compare conventional solution polycondensation reaction methods with microwave‐assisted polycondensation, the reactions were also carried out under microwave conditions in the presence of small amount of o‐cresol that acts as a primary microwave absorber. The reaction mixture was irradiated for 4 min with 100% of radiation power. Several new optically active poly(amide‐imide)s with inherent viscosity ranging from 0.26–0.44 dL/g were obtained with high yield. All of the above polymers were fully characterized by ¹H‐NMR, FTIR, elemental analyses, and specific rotation techniques. Some structural characterizations and physical properties of these new optically active poly (amide‐imide)s are reported. POLYM. ENG. SCI. 46:558–565, 2006. © 2006 Society of Plastics Engineers     

Microwave assisted polycondensation of polyimides by [4,4′‐(hexafluoroisopropylidene)diphthalic anhydride,pyromellitic dianhydride] and [2,4,6‐trimethyl‐m‐phenylenediamine]. Power,time, and solvent effect

The microwave assisted polycondensation of two polyimides were studied using pyromellitic dianhydride (PMDA), and 4,4′‐(hexafluoroisopropyliden)diphthalic anhydride (6FDA) as dianhydride monomers and 2,4,6‐trimethyl‐m‐phenylenediamine (TrmPD), as diamine monomer, under microwave irradiation in DMF and DMSO solvents. The structure and performance of polymers were characterized by Fourier Transform Infrared Spectroscopy (FTIR), viscosity, density, and Thermogravimetric Analysis (TGA). The results show that the polyimides can be obtained in a short reaction time with high intrinsic viscosity and high yield. The effect of the presence of a bridging group, ? C(CF₃)₂? , in the monomer structure is apparent in the permeability parameters of the macromolecules as polymer (6FDA‐TrmPD) always presents better results than polymer (PMDA‐TrmPD). Properties as density and T_g increases with the time exposition to the microwave irradiation. Polyimides obtained present good thermal properties because they began to lose weight in a range of 8–16% at high temperature as 450°C. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Synthesis of novel optically active poly(ester‐imide)s with benzophenone linkages by microwave‐assisted polycondensation

A new simple and rapid polycondensation reaction of 4,4′‐carbonyl‐bis(phthaloyl‐L ‐alanine)diacid chloride [N,N ′‐(4,4′‐carbonyldiphthaloyl)]bisalanine diacid chloride with several diphenols, such as bisphenol‐A, phenolphthalein, 1,8‐dihydroxyanthraquinone, 4,4′‐dihydroxybiphenyl, 1,5‐dihydroxynaphthalene and hydroquinone, in the presence of a small amount of a polar organic medium such as o‐cresol was performed using a domestic microwave oven. The polycondensation reaction proceeded rapidly and was almost complete within 12 min to give a series of poly(ester‐imide)s with inherent viscosities of about 0.35–0.58 dl g⁻¹. The resulting poly(ester‐imide)s were obtained in high yield and are optically active and thermally stable. All the above compounds have been fully characterized by IR spectroscopy, elemental analysis, inherent viscosity (η_inh), solubility test and specific rotation. Thermal properties of the poly(ester‐imide)s have been investigated using thermal gravimetric analysis (TGA). © 2000 Society of Chemical Industry     

Synthesis and Characterization of a New Fluorine‐Containing Polybenzimidazole (PBI) for Proton‐Conducting Membranes in Fuel Cells

A new type of fluorine‐containing polybenzimidazole, namely poly(2,2′‐(2,2′‐bis(trifluoromethyl)‐4,4′‐biphenylene)‐5,5′‐bibenzimidazole) (BTBP‐PBI), was developed as a candidate for proton‐conducting membranes in fuel cells. Polymerization conditions were experimentally investigated to achieve high molecular weight polymers with an inherent viscosity (IV) up to 1.60 dl g^–1. The introduction of the highly twisted 2,2′‐disubstituted biphenyl moiety into the polymer backbone suppressed the polymer chain packing efficiency and improved polymer solubility in certain polar organic solvents. The polymer also exhibited excellent thermal and oxidative stability. Phosphoric acid (PA)‐doped BTBP‐PBI membranes were prepared by the conventional acid imbibing procedure and their corresponding properties such as mechanical properties and proton conductivity were carefully studied. The maximum membrane proton conductivity was approximately 0.02 S cm^–1 at 180 °C with a PA doping level of 7.08 PA/RU. The fuel cell performance of BTBP‐PBI membranes was also evaluated in membrane electrode assemblies (MEA) in single cells at elevated temperatures. The testing results showed reliable performance at 180 °C and confirmed the material as a candidate for high‐temperature polymer electrolyte membrane fuel cell (PEMFC) applications.     

Microwave‐assisted and conventional polycondensation reaction of optically active N,N′‐(4,4′‐sulphonediphthaloyl)‐bis‐L‐leucine diacid chloride with aromatic diamines

3,3′,4,4′‐Diphenylsulfonetetracarboxylic dianhydride ( 1 ) was reacted with L‐leucine ( 2 ) in acetic acid and the resulting imide‐acid ( 3 ) was obtained in high yield. The diacid chloride ( 4 ) was prepared from diacid derivative ( 3 ) by reaction with thionyl chloride. The polycondensation reaction of diacid chloride ( 4 ) with several aromatic diamines such as 4,4′‐sulfonyldianiline ( 5a ), 4,4′‐diaminodiphenyl methane ( 5b ), 4,4′‐diaminodiphenylether ( 5c ), p‐phenylenediamine ( 5d ), m‐phenylenediamine ( 5e ), 2,4‐diaminotoluene ( 5f ), and 1,5‐diaminonaphthalene ( 5g ) was developed by using a domestic microwave oven in the presence of a small amount of a polar organic medium such as o‐cresol. The polymerization reactions were also performed under two conventional methods: low temperature solution polycondensation in the presence of trimethylsilyl chloride, and a short period reflux conditions. A series of optically active poly(amide‐imide)s with inherent viscosity of 0.25–0.42 dL/g were obtained with high yield. All of the above polymers were fully characterized by IR, elemental analyses, and specific rotation techniques. Some structural characterizations and physical properties of these optically active poly (amide‐imide) s are reported. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2992–3000, 2004     

Synthesis of new optically active poly(amide‐imide)s containing EPICLON and L‐phenylalanine in the main chain by microwave irradiation and classical heating

EPICLON [3a,4,5,7a‐Tetrahydro‐7‐methyl‐5‐(tetrahydro‐2,5‐dioxo‐3‐furanyl)‐1,3‐isobenzofurandione] or [5‐(2,5‐dioxotetrahydrofurfuryl)‐3‐methyl‐3‐cyclohexyl‐1,2‐dicarboxylic acid anhydride] ( 1 ) was reacted with L ‐phenylalanine ( 2 ) in acetic acid, and the resulting amic acid was refluxed under a Dean‐Stark system with benzene, which produced diacid ( 3 ) in high yield. Compound ( 3 ) was converted to the diacid chloride ( 4 ) by reaction with oxalyl chloride in dry carbon tetrachloride. The polycondensation reaction of this diacid chloride ( 4 ) with several aromatic diamines such as 4,4′‐sulfonyldianiline ( 5a ), 4,4′‐diaminodiphenylmethane ( 5b ), 4,4′‐diaminodiphenylether ( 5c ), 1,4‐phenylenediamine ( 5d ), 1,3‐phenylenediamine ( 5e ), 2,4‐diaminotoluene ( 5f ), and 1,5‐diaminonaphthalene ( 5g ) was developed by using a domestic microwave oven in the presence of a small amount of a polar organic medium such as N‐methylpyrrolidone ( NMP ). The polymerization reactions were also performed under two different classical heating methods: low temperature solution polycondensation in the presence of trimethylsilyl chloride, and high temperature polymerization. A series of optically active poly(amide‐imide)s with moderate yield and inherent viscosity of 0.14–0.22 dL/g were obtained. All of the above polymers were fully characterized by IR, elemental analyses, and specific rotation. Some structural characterization and physical properties of this optically active poly(amide‐imide)s are reported. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3281–3291, 2004     

Novel optically active poly(amide‐imide)s with tetrahydropyrimidinone and tetrahydro‐2‐thioxopyrimidine moieties by microwave‐assisted polycondensation

Rapid and highly efficient synthesis of novel poly(amide‐imide)s (PAIs) were achieved under microwave irradiation by using a domestic microwave oven from the polycondensation reactions of 4,4′‐carbonyl‐bis(phthaloyl‐L ‐alanine) diacid chloride [N,N′‐(4,4′‐carbonyldiphthaloyl)] bisalanine diacid chloride (1) with six different derivatives of tetrahydropyrimidinone and tetrahydro‐2‐thioxopyrimidine compounds (2a–2f) in the presence of a small amount of a nonpolar organic medium that acts as a primary microwave absorber. Suitable organic media was o‐cresol. The polycondensation proceeded rapidly and was almost completed within 10 min, giving a series of PAIs with inherent viscosities of about 0.25–0.45 dL/g. The resulting PAIs were obtained in high yield and are optically active and thermally stable. All of the above compounds were fully characterized by means of Fourier transform infrared spectroscopy, elemental analyses, inherent viscosity (η_inh), solubility test, and specific rotation. Thermal properties of the PAIs were investigated using thermogravimetric analysis. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2416–2421, 2001     

Poly(amide‐imide)/organoclay nanocomposites using glycine as a natural amino acid: study on fire and thermal behavior

In the present study, new functional poly(amide‐imide)/organoclay nanocomposite films were successfully fabricated through the solution intercalation technique. New poly(amide‐imide) (PAI) containing glycine was synthesized via solution polycondensation of 1,1',3,3'‐tetraoxo(5,5'‐biisoindoline‐2,2'‐diyl)diacetic acid with 4,4′‐diaminodiphenylsulfone. The synthesized PAI was characterized by ¹H NMR, Fourier transform infrared (FTIR) spectroscopy, gel permeation chromatography, elemental analysis and inherent viscosity. Then, PAI/organoclay nanocomposite films containing 4 and 8 wt% of organoclay were prepared via solution intercalation through blending of organoclay 30B with the PAI solution. The nanostructures and properties of the PAI/organoclay were investigated using FTIR spectroscopy, XRD, transmission electron microscopy (TEM), TGA, DSC and microscale combustion calorimetry. XRD and TEM revealed the good dispersion of organoclay in the polymer matrix. TGA indicated that the addition of organoclay into the PAI matrix increases the thermal decomposition temperatures and char yields of the nanocomposites. Organoclay shows a positive effect in improving the flame retardancy of the PAI, reflecting the decrease in heat release rate, the total heat release and the heat release capacity of the PAI nanocomposites, while the thermal stability of the PAI nanocomposites only increased slightly compared with the neat polymer. © 2013 Society of Chemical Industry