低介电常数聚酰亚胺薄膜研究进展

依据国内外低介电常数聚酰亚胺（PI）薄膜材料的专利研究情况,综述了近年来低介电常数PI薄膜的制备方法,包括引入含氟取代基、脂环结构、嵌段结构、微孔结构、无机杂化材料等方法制备低介电常数材料。同时,对低介电常数PI薄膜的研究趋势进行了展望。     

低介电聚酰亚胺复合片材的结构设计与性能研究

基于夹层结构设计,在聚酰亚胺（PI）薄膜夹层间引入多孔聚酰亚胺泡沫（PIF）,成功制备具有低介电常数的PI复合片材,并研究PIF厚度对复合片材介电性能、力学性能和导热性能的影响。结果表明：介电常数随着PIF厚度的增加而增加,厚度为1 mm的复合片材的介电性能最佳,100 Hz下介电常数低至1.55。随着PIF厚度的增加,复合片材的拉伸强度降低,导热系数先降低后趋于平缓。FFF-15-5样品的导热系数最低为0.046 W/（m·K）,复合片材显示良好的隔热性能。该PI复合片材为低介电材料的设计提供新思路。     

聚倍半硅氧烷/聚酰亚胺复合材料制备及性能研究

本文以4,4'-二氨基二苯醚、均苯四甲酸二酐为原料,制备聚酰亚胺(Polyimide,PI)薄膜。并将其与笼型倍半硅氧烷(Polyhedral oligomeric silsesquioxane,POSS),通过原位分散聚合法制备了具有低介电常数POSS/PI复合薄膜。研究了POSS填充量对POSS/PI复合材料介电、热稳定性及力学性能的影响。结果表明:掺入POSS的含量为0.5wt%时,POSS/PI复合材料的介电常数与介电损耗明显降低,热分解温度变化不大,拉伸强度略有降低。     

超低介电常数聚酰亚胺的开发及应用

介绍了超低介电常数聚酰亚胺（PI）的研究开发情况。指出通过合成PI与热不稳定聚合物进行嵌段、接枝共聚制备的PI纳米泡沫材料是一种可用于微电子工业的极富应用前景的低介电常数材料，并对其在微电子工业中的应用作了简要叙述。     

低介电常数聚酰亚胺薄膜的研究进展

低介电常数的聚酰亚胺薄膜在解决超大规模集成电路所引起的RC延迟、串扰、能耗、噪声等问题中有着关键性的作用。文章综述了近几年来国内外低介电常数聚酰亚胺薄膜的制备方法,详细介绍了引入纳米多孔结构、改变聚酰亚胺本体结构以及填充低介电材料这三种研究方法,并对各种方法的优缺点做了简要评价。     

聚酰亚胺/氧化石墨烯复合材料的制备及其性能

以自制的氧化石墨烯(GO)为改性填料,通过原位聚合法制备了聚酰亚胺(PI)/GO复合材料,并对其形貌、结构和性能进行了表征和测试。结果表明:GO的引入未对PI结构产生破坏作用,且有效提高了PI的力学性能、热稳定性和介电性能,降低了吸水率;当GO质量分数为1.5%时,PI/GO复合材料的拉伸强度达126.9 MPa,较PI提高了55.7%;吸水率由3.65%降至0.92%,质量损失5%时的温度较PI提高了5.8℃;当GO质量分数为2.0%时,介电常数(0.1 MHz)较PI提高了83.1%。     

PI/介孔氧化硅复合材料的制备与性能研究

通过四乙氧基硅烷的水解、缩合制备八(四甲基铵)倍半硅氧烷(TMA-POSS),以TMA-POSS为硅源,十六烷基三甲基溴化铵(CTAB)为模板荆,制备了六方有序纳米介孔氧化硅.采用原位聚合法制备了聚酰亚胺(PI)/介孔氧化硅复合材料,并讨论了介孔氧化硅的含量对PI材料的介电常数和热稳定性的影响.结果表明,加入介孔氧化硅有利于降低PI的介电常数和提高热稳定性,当其质量分数为5%时,PL/介孔氧化硅复合材料的介电常数可降至2.69.     

低介电聚合物复合材料发展现状

随着航空、交通以及5G通信领域的快速发展,对聚合物材料的介电性能提出了更高的要求。在大型工业以及科研中,急需开发具有更低介电性能的聚合物材料。聚酰亚胺(PI)、环氧树脂(EP)、氰酸酯树脂(CE)、聚丁二烯树脂(PB)等低介电聚合物在电子通信领域具有较大的发展潜力。综述了PI、EP、CE及PB基复合材料在降低介电常数以及介电损耗等方面的研究进展。降低聚合物介电常数和介电损耗,可以通过生成的空芯或孔隙结构引入空气或者通过降低摩尔极化率,达到改善低介电复合材料介电性能的目的。深入研究了复合材料的介电性能与频率、温度及填料含量的关系,并且提出了关于低介电聚合物基复合材料应用前景和未来发展方向的展望。     

聚酰亚胺纤维对PTFE基板介电和热膨胀性能的影响

采用不同平均长度和质量分数的聚酰亚胺(PI)纤维，用压延方法制备聚四氟乙烯(PTFE)基板，研究PI纤维对PTFE基板介电和热膨胀性能的影响。结果表明，随PI纤维质量分数的提高，PTFE基板介电常数呈现升高的趋势，而介电常数随PI纤维平均长度的变化并不明显。随PI纤维质量分数的提高，PTFE基板厚度方向(Z轴方向)的热膨胀系数(Z-CTE)呈现降低的趋势，当质量分数达到9%以上时，Z-CTE趋于稳定。随PI纤维平均长度的升高，Z-CTE呈下降趋势，PI纤维平均长度超过80μm时，Z-CTE反而上升。在介电常数2.20,Z-CTE越小越好的要求下，通过响应曲面设计，找到最佳理论配方。基于该配方，制备PI纤维质量分数为7.36%、平均长度为68μm的PTFE基板样品，测试介电常数和Z-CTE，结果分别为2.201 5和234.5×10^-6 K^-1，与理论模型计算相符。     

不同方法制备聚酰亚胺/纯硅沸石复合材料的性能对比

文章将纯硅沸石纳米晶(PSZN)与聚酰亚胺(PI)前驱体混合,经旋涂及静电纺丝制备了两种复合膜,并对材料的介电常数及力学性能进行研究与对比。研究结果表明,PI/PSZN复合纤维膜的介电常数约为1.60,而旋涂法制备的复合膜介电常数最低仅为3.11;复合材料的杨氏模量随着PSZN添加量的增加而提高,PI/5 wt%PSZN复合膜和PI/7 wt%PSZN复合纤维膜拉伸强度分别比相应基体增加了19.1 MPa和11.9 MPa。     

Synthesis and Light‐Emitting Properties of New Polyimides Containing Ethynylene Units in the Main Chain

Two new polyimides (ODA‐PI and HDA‐PI) having 1,4‐phenylenediethynylene unit and octyloxy groups were synthesized. Judging from inherent viscosities of their precursor PAAs (1.42 and 1.62 dL · g^?1), the two PIs were very high in molecular weight. Casting and thermal imidization of PAAs results polyimides with good‐quality films. They were stable up to 364 °C and showed no crystallites. UV‐vis and PL spectra in NMP solutions of both PIs showed maxima at 442 and 501 nm, respectively, while PL spectra in ≈10 µm thick films exhibited a maximum at 540 nm. CV indicates that two PIs were electrochemically active in redox region. The devices with construction of ITO/PEDOT/PIs/BAlq₃/LiF/Al exhibited turn‐on voltages of 6.5 V in ODA‐PI and 7.5 V in HDA‐PI and emitted a bright bluish‐green light. ODA‐PI and HDA‐PI showed maximum luminescence of 256 and 316 cd · cm^?2, respectively, at the same voltage of 12 V.

     

热塑性聚酰亚胺微电子薄膜的制备

以微电子业所急需的聚酰亚胺薄膜为背景,采用一种热塑性聚酰亚胺树脂(TPI),实验测定了聚合物溶液特性、干燥工艺及热拉伸性能。在化学环化过程中聚合物溶液粘度随时间逐步增大;15 h后粘度和重均相对分子质量及分布趋于稳定。薄膜溶剂含量在干燥初期急剧下降,干燥速率随干燥温度升高而增大。TPI树脂表现出良好的热塑拉伸性能,当温度高于其玻璃化温度时,最大拉伸比随升温速率降低而增大,而随拉伸载荷增加呈现出先增后降。TPI薄膜经拉伸处理后其力学性能得到明显提高,综合性能与日本钟渊TP E薄膜相当。     

制备高反射高导电的聚酰亚胺银膜的新方法——原位一步法制备技术

采用原位一步法,通过选用不同原材料和制膜工艺,制备了高反射、高导电的聚酰亚胺/银复合膜,该薄膜兼具有银的高反射率和高导电性以及聚酰亚胺的高强度和耐高低温性.银以纳米粒子形式镶嵌于聚酰亚胺表面,使银层与聚酰亚胺基体之间形成强烈的互锁结构,从而不易脱落,该薄膜可用于反射和导电涂层.     

High-permeability fluorinated polyimide microcapsules by vapor deposition polymerization

Spherical microcapsules (∼1 mm in diameter and ∼1 μm in wall thickness) to be used as inertial confinement fusion targets were prepared from 6FDA-ODA polyimide by vapor deposition polymerization. Compared with the previously developed PMDA-ODA polyimide microcapsules, the 6FDA-ODA microcapsules were ∼50-fold more permeable to gases including He, D₂, O₂, N₂, Ar, and Ne, considerably more transparent in the UV-visible spectrum, and of marginally lower Young's modulus, tensile strength, and elongation at break. The microcapsules possessed amorphous morphology with an amorphous d-spacing of 5.8 Å as determined by wide-angle X-ray diffraction. The cryogenic permeability of helium was measured between 133 and 295 K, and the activation energy for permeation was determined to be 12.3 kJ/mol.     

Wear,thermal, and physical properties of fluorine-containing polyimide/silica hybrid nanocomposite coatings

This study prepared fluorine and SiO₂ particles containing organic–inorganic hybrid polyimide nanocomposite coatings (PISFs) with inorganic content in the range of 5–20% in pure polyimide solutions via the sol–gel process. Polyimide hybrid structures containing fluorine and SiO₂ particles were synthesized by using perfluorooctyltriethoxysilane and tetraethyl orthosilicate. These formulations were applied on aluminum sheets by using a 75 μm wire wound applicator, and the coatings were cured for 8 h at room temperature and then 24 h at 100 °C. Increased inorganic contents caused slight decreases in the initial decomposition temperatures, but the char yield values increased for PISF15 and PISF20. All samples exhibited hydrophobic properties. When all samples were compared, PISF5 and PISF10 exhibited hydrophobicity, high wear resistance and thermal properties. Additionally, PISF5 and PISF10 showed high adhesion, hardness, and methyl ethyl ketone solvent resistance. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47399.     

聚酰亚胺薄膜的回收与综合利用

介绍国内外聚酰亚胺废膜的回收与综合利用方法。随着环境保护意识的增强和发展循环经济的需要,人们越来越重视广泛应用于信息记录和影像材料等诸多领域中的聚酰亚胺薄膜的回收与综合利用。人们不仅注意由聚酰亚胺废膜回收单体原料的方法。更加关注,以聚酰亚胺废膜为原料直接生产其它聚酰亚胺产品的方法。     

Dendronized Polyimides Bearing Long-Chain Alkyl Groups and Their Application for Vertically Aligned Nematic Liquid Crystal Displays

Polyimides having dendritic side chains were investigated. The terphenylene diamine monomer having a first-generation monodendron, 3,4,5-tris(n-dodecyloxy)-benzoate and the monomer having a second-generation monodendron, 3,4,5-tris[-3’,4’,5’-tri(n-dodecyloxy)benzyloxy]benzoate were successfully synthesized and the corresponding soluble dendritic polyimides were obtained by polycondensation with conventional tetracarboxylic dianhydride monomers such as benzophenone tertracarboxylic dianhydride (BTDA). The two-step polymerizations in NMP that is a general method for the synthesis of soluble polyimides is difficult; however, the expected dendritic polyimides can be obtained in aromatic polar solvents such as m-cresol and pyridine. The solubility of these dendoronized polyimides is characteristic; soluble in common organic solvents such as dichloromethane, chloroform, toluene and THF. These dendronized polyimides exhibited high glass transition temperatures and good thermal stability in both air and under nitrogen. Their application as alignment layers for LCDs was investigated, and it was found that these polyimides having dendritic side chains were applicable for the vertically aligned nematic liquid crystal displays (VAN-LCDs).     

4-（3，5-二氨基苯甲酸甲酯基）三苯胺的合成及其聚酰亚胺

以三苯胺为原料,通过Vilsmeier—Haack反应、酯化和还原等反应合成了含三苯胺基团的二胺单体4-（3,5-二氨基苯甲酸甲酯基）三苯胺,然后使它和4,4’-二氨基二苯醚与2,2-双[4-（3,4-二羧酸基苯氧基）苯基]丙烷二酐在N-甲基-2-吡咯烷酮溶剂中进行共聚合反应,经热环化脱水得到含三苯胺基团的聚酰亚胺。采用FTIR、1HNMR、UV—Vis、荧光分光光度计等仪器对合成的聚酰亚胺结构和性能进行了表征。结果表明,含三苯胺基团聚酰亚胺呈现明显的荧光特性。     

聚酰亚胺薄膜及纤维的探索研究

利用均苯四甲酸二酐(PMDA)、4,4'-二氨基二苯醚(4,4'-ODA)和自制三单体在强极性非质子有机溶剂N,N-二甲基乙酰胺(DMAc)中进行共缩聚反应,制得高粘度的聚酰胺酸(PAA)溶液,经涂膜、热亚胺化,得到坚韧透明的聚酰亚胺(PI)薄膜,其具有较好的拉伸断裂强度和合适的伸长率;同时将得到的PAA溶液进行湿法纺丝,制成PAA纤维,采用热亚胺化和高温拉伸的方法制得PI纤维,其断裂强度能达到3.67cN/dtex。     

Solvent Effects on High Temperature Polyimides and their Bonded Joints

Environmental stress crazing/cracking (ESCR/C) of adhesives under organic solvent exposure is a subject of great practical importance to adhesive end-users, especially in dealing with structural applications. In the past, the mechanical properties of several adhesive systems have been shown to degrade considerably after both prolonged and momentary exposure to solvents under a state of stress. In this study, the solvent resistance of three structural polyimide adhesives was studied, with respect to organic solvents that may come in contact with the adhesives during their service life. Initially, dog-bone samples of the resin systems were prepared, according to ASTM Standard D638-91a, and these were soaked in the solvents to obtain equilibrium solvent mass uptake curves. The solvents used in the study included acetone, methyl ethyl ketone (MEK) and ethylene glycol, among others. The equilibrated samples were then tested in a miniature tensile testing machine, to obtain stress-strain characteristics. Secondly, samples equilibrated in the solvents were held in a vacuum environment at 150°C (which is below the glass transition temperature of the adhesives) to desorb the solvent, and these were then tested to obtain residual properties. To study the durability of bonded joints under solvent exposure, Ti-6A1-4V/adhesive bonds were prepared and wedge tests were performed on them for periods up to several days in solvent baths. Based on the measured crack lengths, the strain energy release rate due to solvent-induced environmental stress cracking (G_ESC) was computed as a function of crack growth rate. The G_ESC measurements help quantify the durability of the bonded joints on exposure to the various solvents, and further help in ranking the adhesives in terms of solvent resistance.