含烷基取代基柔性聚酰亚胺薄膜的制备

以柔性二胺单体1,3-双(4-氨基苯氧基)苯(134BAPB)和含支链二胺单体3,3′-二乙基-4,4′-二氨基二苯甲烷(DEMMD)与3,3′,4,4′-二苯酮四酸二酐(BTDA)进行三元共聚,制备了一系列聚酰亚胺(PI)薄膜。通过傅里叶红外光谱、差示扫描量热仪、热重分析仪、热机械分析仪及电子万能材料试验机对材料的结构、热性能和力学性能进行了表征。结果表明PI薄膜已经成功制备,热性能与力学性能良好。     

含噁唑环均苯型聚酰亚胺的制备和表征

为了提高聚酰亚胺材(PI)料的耐热性能,以2,6-二(对氨基苯)苯并[1,2-d;5,4-d]二噁唑为单体,采用两步法与均苯四甲酸二酐(PMDA)合成出了新型聚酰亚胺薄膜.采用红外光谱、热分析等手段对其结构与性能进行了表征.测定了聚酰亚胺的预聚体-聚酰胺酸(PAA)的特性黏度达到1.18dL/g,玻璃化温度343℃,在空气中热失重温度为626℃,表现出优异的热氧化稳定性.评价了聚酰亚胺在各种溶剂中的溶解性能,均不溶于常规的极性溶剂,甚至在浓硫酸中也不溶解.经红外光谱测定,聚酰胺酸基本转化成聚酰亚胺.     

2，6-二（对氨基苯）苯并[1，2-d；5，4-d＇]二噁唑的合成

2,6-二（对氨基苯）苯并[1，2-d；5，4-d’]二噁唑是一种重要的有机二胺，可与不同二酐单体缩聚合成聚酰亚胺。由于其分子结构中含有苯并双噁唑官能团，因而具有优异的热性能，使得合成的聚酰亚胺具有更出色的耐热性。     

含苯并噁唑结构耐高温聚酰亚胺模塑料制备及性能

为提高聚酰亚胺(PI)模塑料的耐高温性能,以2–(4–氨基苯基)–5–氨基苯并噁唑(BOA)和二氨基二苯醚作为混合二胺与均苯四甲酸酐合成聚酰胺酸树脂,随后通过热亚胺化法制备得到不同噁唑单元添加量的PI模塑粉。利用傅立叶变换红外光谱对模塑粉化学结构进行表征,并考察其在氮气和氧气氛围中的热失重行为。通过热模压方法制备得到含苯并噁唑结构的耐高温PI模塑料,对模塑料室温和430℃高温条件下力学性能进行测试,并对其高温性能稳定性和尺寸稳定性进行表征分析。结果表明,通过两步法和热亚胺化法成功将噁唑基团引入到PI结构中;随着BOA引入量的增加,模塑粉耐热氧稳定性显著提升,模塑料室温拉伸性能有所下降,压缩性能提升,但430℃高温下拉伸性能和压缩性能均优于不含BOA的模塑料,且力学性能保持率显著提高;BOA的引入还提高了PI材料高温性能稳定性,显著降低线性热膨胀系数,含苯并噁唑结构的PI模塑料展现出优越的耐高温性。     

可溶性聚酰亚胺树脂的合成及其薄膜制备

以含支链3,3′-二乙基-4,4′-二氨基二苯甲烷(M-OEA)为二胺单体,采用高温一步法与四种二酐进行聚合,合成了四种聚酰亚胺(PI)树脂,并制备了一系列聚酰亚胺薄膜。对聚酰亚胺树脂进行了溶解性测试,并通过傅里叶红外光谱、紫外-可见分光光度计、差示扫描量热仪、热重分析仪、静态热机械分析仪及电子万能材料试验机对PI薄膜的结构、光学性能、热性能和力学性能进行了表征。结果表明,该系列树脂溶解性优异,薄膜热稳定性良好,5%热失重温度(T_g⁵)均在390℃以上,玻璃化转变温度(T_g)均高于230℃,两种半脂环族PI薄膜的光学性能优异,紫外截止波长280 nm。     

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。     

苯并噁唑型聚酰胺-酰亚胺的制备与性能研究

以氯化偏苯三酸酐与2-(4-氨基苯基)-5-氨基苯并噁唑为原料,通过预聚合、亚胺化两步反应合成了苯并噁唑型聚酰胺-酰亚胺。考察了不同反应温度及固含量对聚酰胺酸分子量的影响,确定了最佳的预聚合工艺。研究了苯并噁唑型PAI在不同化学溶剂中的溶解特征。通过傅里叶变换红外光谱(FTIR)与核磁共振氢谱(~1H NMR)表征了苯并噁唑型聚酰胺-酰亚胺的化学结构,采用差示扫描量热分析(DSC)与广角X射线衍射(WAXD)表征了材料的聚集态结构,并通过热失重(TG)分析了材料的热性能。结果表明,所制备得到的苯并噁唑型PAI为无定型态,具有优异的耐溶剂性与热稳定性。     

含芳杂环结构的聚酰亚胺/SiO2杂化薄膜及性能研究

以均苯四甲酸二酐(PMDA)为二酐单体,对苯二胺(p-PDA)、2-(4-氨基苯基)-5-氨基苯并噁唑(BOA)和2-(4-氨基苯基)-5-氨基苯并咪唑(BIA)为二胺单体,制备了聚酰亚胺(PI)树脂和薄膜,又采用三辊机制备了PI/SiO_2杂化树脂和薄膜。利用傅里叶红外光谱对材料的结构进行了表征,结果表明薄膜完全亚胺化,且SiO_2存在于PI基体中。此外,还研究了PI和PI/SiO_2杂化薄膜的热学性能和力学性能。随着2种不同粒径SiO_2的加入,PI/SiO_2杂化薄膜的耐热性能得到明显改善。与纯PI相比,PI/SiO_2杂化薄膜的玻璃化转变温度上升3～16℃,1%热失重温度提高了14～30℃,而且线性热膨胀得到抑制,PI-R106-5的线性热膨胀系数(CTE)仅为2.59×10~(-6)/℃。但是,PI/SiO_2杂化薄膜的力学性能相对于纯PI薄膜有所降低,未来应继续提高其相容性。     

含酮柔性共聚型聚酰亚胺性能研究

为了考察柔性二酐共聚对聚酰亚胺(PI)薄膜性能的影响,用含柔性基团的酮酐单体3,3',4,4'-二苯酮四酸二酐(BTDA)、刚性二酐单体均苯四甲酸二酐(PMDA)和芳香二胺4,4'-二氨基二苯醚(ODA)共聚,制得共聚聚酰亚胺薄膜.分别用FT-IR(ATR)、TMA、TGA、万能试验机对薄膜的结构、热性能及力学性能进行了测定.结果表明,聚合物亚胺化程度完全,且随着柔性二酐的加入聚合物的热性能得到明显改善,同时力学性能数据也表明,共聚物柔性增强,材料的加工性得到提高.     

一种三元共聚型聚酰亚胺的制备与表征

以3,3'-二甲基-4,4'-二氨基二苯甲烷、1,3-双(4-氨基苯氧基)苯(1,3-APB)与3,3',4,4'-二苯醚四羧酸二酐(ODPA)进行缩聚反应,制得一种新型的三元共缩聚型聚酰亚胺。将此聚合物与两种二元共缩聚型聚酰亚胺的性能进行对此,发现三元共聚型聚酰亚胺的溶解性能、力学性能和热性能皆较好,且使用范围扩大。     

A comparison of physical and mechanical properties of polyimide films containing different metal ions

Metal ions have been incorporated into linear polyimide films in order to improve the potential of these materials for applications in space. Various metals such as Al, Pd, Ag, Au, and Sn in a variety of chemical states were added to a polyamic acid prepared from 3,3′, 4,4′-benzophenone tetracarboxylic acid dianhydride and 4,4′-oxydianiline. Films of the metal ion-filled polyamic acids were prepared and cured to the corresponding polymides by heating at 300°C in air. The cured films were characterized for such properties as glass transition temperature, electrical conductivity, and thermal stability. Modulii and tensile strengths of the metal-containing polymide films were obtained at both ambient and elevated temperatures. Comparison of the physical and mechanical properties of these polyimide films as a function of metal additive is made.     

均苯型共聚聚酰亚胺薄膜的制备及其性能

以2,2′-双[3-苯基-4(4-氨基苯氧基)苯基]丙烷(BPAPOPP)、4,4′-二胺基二苯醚和均苯四甲酸酐为原料,采用两步法共缩聚制备了一系列共聚聚酰亚胺薄膜。采用红外光谱仪、差示扫描量热仪等分析了薄膜的结构,利用静态热机械分析仪分析了薄膜的性能。结果表明:制备的聚酰亚胺薄膜具有较低的玻璃化转变温度;随着BPAPOPP含量的增加,薄膜的热性能有所降低,但其溶解性能得到了改善。     

新型聚酰亚胺薄膜的制备及其性能研究

采用2,4,6-三甲基间苯二胺（TMmPDA）、4,4＇-二氨基二苯醚（DADPE）和3,3＇,4,4＇-四羧基联苯二酐（BP-DA）为主原料,摩尔比为1∶4∶5,合成得到了三甲基间苯二胺型聚酰胺酸（TMPAA）溶液,涂膜,热亚胺化,制得了三甲基间苯二胺型聚酰亚胺（TMPI）薄膜,并对其粘度、力学性能等进行了研究。     

Synthesis and properties of the amino‐functionalized multiple‐walled carbon nanotubes/polyimide nanocomposites

The 1,6‐hexanediamine‐functionalized multi‐walled carbon nanotubes(a‐MWNTs)/polyimide(PI) nanocomposite films were prepared through in‐situ polymerization followed by mixture casting, evaporation, and thermal imidization. To increase the compatibility of carbon nanotubes with the matrix polyimide, a‐MWNTs was used as the filler. According to the results, a‐MWNTs were homogeneously dispersed in the nanocomposite films. With the incorporation of a‐MWNTs, the mechanical properties of the resultant films were improved due to the strong chemical bonding and interfacial interaction between a‐MWNTs and 4,4′‐oxydiphthalic anhydride(ODPA)/4,4′‐Oxydianiline(ODA) polyimide matrix. The thermal stability of the a‐MWNTs/polyimide nanocomposite was also improved by the addition of a‐MWNTs. The electrical tests showed a percolation threshold at about 0.85 vol% and the electrical properties were increased sharply. POLYM. COMPOS., 2009. © 2008 Society of Plastics Engineers     

Synthesis and properties of aromatic polyimide,poly(benzoxazole imide), and poly(benzoxazole amide imide)

Two series of heterocyclic aromatic polymers were synthesized from 4,4′‐(4,4′‐isopropylidenediphenoxy)bis(phthaltic anhydride) and 2,2′‐bis(3,4‐dicarboxyphenyl)hexafluoropropane dianhydride by two‐step method. The inherent viscosities were in the range of 24–45 cm³/g. The effects of the rigid benzoxazole group in the backbone of copolymer on the thermal, mechanical, and physical properties were investigated. These polymers exhibit good thermal stability. The temperatures of 5% weight loss (T₅) of these polymers are in the range of 403–530°C in air and 425–539°C in nitrogen. The chard yields of these polymers are in the range of 15–24% in air and 54–61% in nitrogen. These polymers also have high glass‐transition temperatures and a low coefficient of thermal expansion and good mechanical properties. The poly(benzoxazol imide) has a higher tensile strength and modulus than those of neat polyimide. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Residual stress and mechanical properties of polyimide thin films

Four different structure polyimide thin films based on 1,4‐phenylene diamine (PDA) and 4,4′‐oxydianiline (ODA) were synthesized by using two different dianhydrides, pyromellitic dianhydride (PMDA) and 3,3′,4,4′‐biphenyltetracarboxylic dianhydride (BPDA), and their residual stress behavior and mechanical properties were investigated by using a thin film stress analyzer and nanoindentation method. The residual stress behavior and mechanical properties were correlated to the morphological structure in polyimide films. The morphological structure of polyimide thin films was characterized by X‐ray diffraction patterns and refractive indices. The residual stress was in the range of ?5 to 38 MPa and increased in the following order: PMDA‐PDA < BPDA‐PDA < PMDA‐ODA < BPDA‐ODA. The hardness of the polyimide films increased in the following order: PMDA‐ODA < BPDA‐ODA < PMDA‐PDA < BPDA‐PDA. The PDA‐based polyimide films showed relatively lower residual stress and higher hardness than the corresponding ODA‐based polyimide films. The in‐plane orientation and molecularly ordered phase were enhanced with the increasing order as follows: PMDA‐ODA < BPDA‐ODA < BPDA‐PDA ～ PMDA‐PDA. The PDA‐based polyimides, having a rigid structure, showed relatively better‐developed morphological structure than the corresponding ODA‐based polyimides. The residual stress behavior and mechanical properties were correlated to the morphological structure in polyimide films. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Preparation and properties of polyimide nanocomposites via a soluble polyisoimide precursor

A polyisoimide based on 4,4′‐oxydiphthalic dianhydride and 4,4′‐oxydianiline was synthesized and used for the preparation of nanocomposites with commercial organoclays by the solution dispersion technique. The cast composite films were heat‐treated to convert them into polyimide nanohybrid films. Homogeneous dispersions were obtained at lower clay concentrations (<5 wt %), and this was confirmed by X‐ray diffraction and transmission electron microscopy. The nanocomposites displayed improved thermal and mechanical properties. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 869–874, 2006     

Preparation and characterization of magnetic polyimide hybrid thin films

Magnetic polyimide hybrid thin films were synthesized from pyromellitic dianhydride (PMDA), 4,4′-oxydianiline (ODA), and Fe₃O₄ magnetic nanoparticles via thermal imidiazation in nitrogen environments. The magnetic polyimide hybrid thin films were analyzed and characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The magnetic properties of magnetic nanoparticles and polymer hybrid thin films were assessed using a vibrating sample magnetometer (VSM), and the physical properties of hybrid thin films were tested. Results revealed that the magnetic polyimide hybrid thin films had superparamagnetic behavior and excellent mechanical properties. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

新型含吡啶环芳香二胺及其可溶性聚酰亚胺的合成与表征

以苯甲醛和3-(4-硝基苯氧基)苯乙酮(NPAP)为原料,通过改进的Chichibabin反应制备了硝基化合物4-苯基-2,6-双[3-(4-硝基苯氧基)苯基]吡啶(PNPP),再用Pd/C和水合肼将PNPP进行还原,成功制备了一种新型含吡啶环的芳香二胺4-苯基-2,6-双[3-(4-胺基苯氧基)苯基]吡啶(PAPP)。以PAPP作为二胺,3,3′,4,4′-二苯醚四羧酸二酐(ODPA)作为二酐,N,N-二甲基甲酰胺(DMF)为溶剂,通过常规的两步法,经热或者化学亚胺化形成聚酰亚胺,制得了一种新型的含吡啶环聚酰亚胺。所得聚酰胺酸和聚酰亚胺的粘度分别为0.59 dL/g和0.56 dL/g。化学亚胺化所得的聚酰亚胺速溶于常见有机溶剂如DMF、N,N-二甲基乙酰胺(DMAc)、N-甲基-2-吡咯烷酮(NMP)、四氢呋喃(THF)等。制得了柔韧的聚酰亚胺膜,膜有很好的热稳定性,玻璃化转变温度(T_g)为230.8℃,氮气氛中10%失重温度为552.0℃,同时,膜还有较好的力学性能,拉伸强度为88.6 MPa,拉伸模量为1.04 GPa,断裂伸长率为8.7%,膜的吸水率为0.89%。     

含羟基聚酰亚胺改性环氧胶的制备及性能研究

将3,3'-二氨基-4,4'-二羟基联苯(DADHBP)、2,2-双(3-氨基-4-羟基苯基)六氟丙烷(BAH-PFP)和3,3',4,4'-四羧酸二苯醚二酐(ODPA)、3,3',4,4'-四羧酸二苯甲酮二酐(BTDA)单体聚合,再经亚胺化得到含羟基聚酰亚胺(HPI)粉末,采用傅里叶红外光谱对其进行了表征。由HPI、烯丙基双酚A、双马来酰亚胺、2-乙基-4-甲基咪唑与N,N,N',N'-四缩水甘油基-4,4'-二氨基二苯甲烷(TGDDM)共聚反应制得胶粘剂,并对胶粘剂的热性能、力学性能及吸水性进行了研究,结果表明:该胶拉伸剪切强度为21.1 MPa,固化后吸水率为0.49%。通过凝胶化时间法计算胶粘剂的表观活化能为64.5 kJ/mol。