聚酰亚胺/无机纳米杂化材料的研究

聚酰亚胺是一种综合性能优异的材料,现已被广泛应用于航空航天及微电子领域.但是其明显的性能缺陷限制了其在高温和精密状态下的应用;而无机纳米粒子的引入,大大弥补了其性能缺陷（如较高的热膨胀系数和较低的吸水性）,非常适合对PI改性.本文阐述了PI纳米杂化材料的制备方法,介绍了纳米杂化材料的特点及应用.     

聚酰亚胺／纳米Al2O3-SiO2和聚酰亚胺／纳米Si3N4杂化材料的结构与性能研究

将纳米Al2O3-SiO2、Si3N4分别均匀分散于聚酰亚胺（PI）前驱体聚酰胺酸中，经过热亚胺化制备了PI／纳米Al2O3-SiO2和PI／纳米鼠N4杂化材料。通过傅里叶变换红外光谱仪、X射线衍射仪、高温微量热天平、静态热机械分析仪和差示热分析仪对杂化材料的微观结构及热性能进行了研究，结果表明，杂化材料中聚酰亚胺和无机纳米粒子之间存在相互作用，形成了复合相态结构；加入纳米Al2O3，SiO2、Si3N4后杂化材料的热稳定性均高于纯聚酰亚胺，但并不完全随无机纳米粒子含量的增加而提高；与纯PI相比，在90～130℃的温度范围内PI-8％Al2O3-SiO2、PI-8％鼠Si3N4热膨胀系数分别降低了约11％和47％，加入8％纳米Al2O3-SiO2、Si3N4后杂化材料的热导率分别提高了约8％和13％。PI／纳米Al2O3-SiO2、Si3N4杂化材料不仅保留了PI原有的优异性能，而且充分发挥了纳米无机粒子对PI的特殊改性性能。     

纳米粒子改性聚酰亚胺现状及进展

由于聚酰亚胺(PI)材料存在亲水性较弱、加工成型性较难、电导率较低等缺陷，需要通过纳米粒子改性聚酰亚胺改善其性能。基于不同纳米粒子改性聚酰亚胺，综述并评论了国内外聚酰亚胺纳米复合材料的研究现状，阐述了有机纳米粒子(CNC、FEP)、无机纳米粒子(陶瓷材料、金属纳米粒子、蜂窝芯材)、有机-无机纳米粒子(POSS、MWCNTs-COOH、OGO)复合改性聚酰亚胺性能的原理和效果，分析了聚酰亚胺复合杂化过程中面临的问题和改进方法，结合目前聚酰亚胺复合材料发展集中在合成工艺改进、填料优化改性等方面的研究趋势，提出了聚酰亚胺未来的研究方向。     

热固性聚酰亚胺复合材料的制备及性能研究

以均苯四甲酸二酐、二胺基二苯醚、N,N′-二甲基乙酰胺及纳米SiC为原料,经加热固化等工艺制备了热固性聚酰亚胺(PI)/纳米SiC复合材料。经测试,该复合材料的介电常数和吸水率均比纯PI明显降低,且复合材料中低分子纳米SiC均匀分散到PI内部,形成网络状杂化复合体系。     

聚酰亚胺/无机粒子复合材料的制备及其性能研究进展

综述了聚酰亚胺(PI)与无机粒子复合的研究进展,着重介绍了复合材料的溶胶-凝胶法、插层复合法、机械共混法三种制备方法。将PI与无机材料复合可得到集有机材料和无机材料优异性能于一体的复合材料,改善了传统PI存在的不足。无机粒子改性后的PI在不明显降低材料的热性能和力学性能的同时富集了无机小分子高模量、耐氧化、耐摩擦等性能,优化了材料的性能。引入无机纳米粒子,材料的内部分子堆积、相互作用等发生改变,对气体的选择透过性有很大的改善。改性后的PI具有可控的介电性能、膨胀性能等。     

聚酰亚胺/纳米二氧化钛复合薄膜制备及表征

采用超声分散-原位聚合的方法,制备了不同纳米二氧化钛(TiO2)含量的聚酰亚胺(PI)/纳米TiO2复合薄膜,通过X射线衍射、紫外可见光谱分析、扫描电子显微镜、红外光谱对薄膜的形态结构及纳米颗粒在复合物中的分散性进行了表征分析.结果表明,纳米TiO2以球状微粒均匀分散在PI基体中,表观粒径约为300 nm(杂化包覆后的粒径),晶形仍为锐钛矿型;纳米TiO2粒子的引入,提高了PI薄膜对可见光的吸收.     

两步亚胺化-再沉淀法制备聚酰亚胺纳米粒子

以再沉淀法为手段,经两步亚胺化的聚酰亚胺(PI)溶液为原料,在溶液体系下制备了PI纳米粒子,并对PI纳米粒子的粒径分布、形貌以及性能进行了表征.结果表明PI粒子的粒径分布受到分散剂、搅拌速度等因素的影响;PI粒子在固含量为1%时,晕现良好球形形貌;PI粒子由较纯的聚酰亚胺构成,在空气和氮气环境下均具有良好的热稳定性.     

聚酰亚胺/无机纳米粒子复合材料在介电领域应用

传统的聚酰亚胺材料的介电常数范围通常在3. 0～3. 6之间,是电子电工领域应用较多的绝缘介质材料。随着相关行业技术的不断发展,对聚酰亚胺材料的要求也越来越高。目前,具有高介电常数的聚酰亚胺复合材料薄膜正越来越多地被人们研究。通过向聚酰亚胺体系内加入不同类型的无机纳米粒子,可以不同程度低提高聚酰亚胺体系的介电常数。本文列举了不同类型无机纳米粒子掺杂的聚酰亚胺复合材料的制备及表征工作,并对其应用进行了展望。     

反胶束法制备感光聚酰亚胺/TiO2纳米杂化感光材料

采用反胶束法合成TiO2纳米粒子与感光聚酰亚胺溶液混合制备纳米杂化感光材料,用热台偏光显微镜表征了杂化材料的光刻能力及形貌,用UV光谱表征了杂化材料的TiO2纳米粒子的存在,用椭圆偏振仪测定了杂化材料薄膜的折光指数。     

聚酰亚胺(PI)/无机纳米复合材料的制备、结构与性能

依据国内外聚酰亚胺（PI）／纳米复合材料的最新研究进展，重点阐述PI复合材料的制备、结构、性能及应用，展望了PI复合材料的发展趋势。列举了几种常用纳米粉体的特性，介绍了聚酰亚胺（PI）纳米复合材料的3种制备方法：溶胶一凝胶法、插层复合法、直接分散法，由于纳米粉体在PI材料中的分散性良好，使整个聚合物基体形成新的网络结构，利用纳米粉体改变了PI材料的性能，如力学性能、热学性能、加工流动性等，插层剂的加入对PI纳米复合材料的复合体系有明显改善作用。     

有机／无机型复合粉粒——一类崭新的粉体材料

介绍了复合粉粒的发展现状，并对作为有机／无机复合粉粒重要基础原材料的聚合物微球及其生产进行了阐述和分析。指出开发聚合物粒子的重要性在于将其作为功能性高分子粉末以及它与其他物质复合，创制出新的功能性材料两个方面。     

Morphology and size control of inorganic particles in polyimide hybrids by using SiO2-TiO2 mixed oxide

Polyimide/inorganic hybrids were prepared by sol-gel reaction starting from tetraethoxysilane (TEOS), and tetrabutyl titanate (TBT) in the solution of polyamic acid in N,N-dimethylformamide. The hybrid films were obtained by the hydrolysis-polycondensation of TEOS and TBT in polyamic acid solution, followed by the elimination of solvents and imidization process. Binary polyimide/SiO₂ and polyimide/TiO₂ hybrids, as well as ternary polyimide/SiO₂-TiO₂ hybrids (with varied ratio of SiO₂ to TiO₂) were prepared to study the effects of the recipes and inorganic components on the morphologies of the polyimide hybrids. Transparent films with much higher inorganic content can be obtained in ternary polyimide hybrids, while lower inorganic content in binary hybrids. The results also indicate that the inorganic particles are much smaller in the ternary systems than in the binary systems, the shape of the inorganic particles and the compatibility for polyimide and inorganic moieties are varied with the ratio of the inorganic moieties in the hybrids. The completely imidization temperature of the polyamic acid was delayed, and furthermore, the thermal stability of polyimide was enhanced through the incorporation of the inorganic moieties in the hybrid materials.     

聚酰亚胺/二氧化硅复合薄膜电学性能的研究

用均苯四甲酸二酐(PMDA)与4,4'-二氨基二苯醚(ODA)为单体,以N,N-二甲基乙酰胺(DMAC)为溶剂,通过超声机械共混法制备聚酰亚胺/二氧化硅(PI/SiO2)复合薄膜,采用红外光谱(FTIR)、扫描电镜(SEM)分别对PI复合薄膜的结构和表面形貌进行了研究表征,通过concept 80宽带介电谱测试系统对复合薄膜电学性能进行了研究。结果表明:在一定的频率下,不同无机纳米粒子含量的复合薄膜中,介电常数和介电损耗角正切随无机纳米质量分数的增加而增大。     

Morphology and thermo‐mechanical properties of compatibilized polyimide‐silica nanocomposites

Polyimide‐silica nanocomposites have been prepared from an aromatic polyamic acid derived from pyromellitic dianhydride and oxydianiline and a silica network using the sol‐gel reaction. Compatibilization of the two components was achieved by modifying the silica network with imide linkages. Morphology, thermal, and mechanical properties of these composite materials were studied as a function of silica content and compared with the one in which reinforcement of the polyimide was achieved using a pure silica network. There was considerable reduction in the silica particle size with more homogeneous distribution in the matrix when imide spacer groups were introduced in the silica network. The tan δ spectra obtained from dynamic thermal mechanical analysis shows a large increase in the glass transition temperature with increasing silica content for the compatibilized system in contrast to the un‐compatibilized one. Mechanical properties of the polyimide composites improved due to better interaction between the organic and inorganic phases. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 2521–2531, 2005     

TEM,XPS and thermo-mechanical properties of novel sustainable hybrid coatings

This work contributes to the development of a new generation of protective coatings composed of organic–inorganic materials. A silica based hybrid film was used in this work as high performance materials. The silica sol–gel film reveals enhanced thermo-mechanical properties in comparison with the pure polymer film. Herein, we demonstrate the possibility of employing cheap SiO₂ as prospective nano-fillers for hybrid coatings with active thermo-mechanical properties. Organic–inorganic hybrid coatings based on polyimide and silica were synthesized through a simple physical mixing technique. 3,3′,4,4′-Biphenyltetracarboxylic dianhydride (BPDA), benzene-1,3-diamine (BDA), 3,3′-oxydianiline (ODA) and SiO₂, were used as precursors for the hybrid coatings. These hybrid coatings were deposited via spin coating onto a galvanized iron, aluminum and copper in order to study the adhesive strength. The effects induced by the silica content on the mechanical properties of the coated samples were investigated. The mechanical properties of hybrid composite were found to be enhanced compared to polyimide coating. The main objective was to observe potential improvements in the mechanical and thermal properties of PI–silica hybrid films. Morphology, and structural changes in the composite films were studied as well as adhesion and impact strength and these characteristics were compared with those of unreinforced polyimide films.     

聚苯胺/无机粒子复合材料的研究进展

主要综述了纳米聚苯胺与无机粒子(如无机磁性粒子、金属氧化物、碳基无机物等其他无机粒子)复合制备的功能性复合材料的力学、光学、电学和磁学性能以及此类功能性复合材料在金属防腐和防污、电磁屏蔽、光学催化、电池材料以及化学传感器等方面的应用前景,并介绍了近几年来各类纳米聚苯胺/无机粒子功能性复合材料在电磁屏蔽、隐身材料、抗静电材料、导电高分子电容器、发光二极管以及二次电池等方面的研究现状及未来发展趋势.     

Preparation and characterization of polyimide/silica‐barium titanate nanocomposites

The silica‐barium titanate (SiO₂‐BaTiO₃) nanocomposites coated with polyimide had been synthesized successfully by a dispersion polymerization method. The conformation, structure, and size of SiO₂‐BaTiO₃ nanocomposites coated with polyimide were investigated by using FT‐IR, EDAX, XRD,TEM, SEM, and TGA. The results indicate that there is a thin layer polymer of SiO₂‐BaTiO₃ nanocomposites surface, in which the polymer thickness is about 10 nm and the size of them are about 50–60 nm, and the particles are well‐dispersed with even particle size. In addition, the crystal structure of BaTiO₃ is stable in preparing composite process and the chemical bond is formed between the inorganic phase and the polymer matrix. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers     

Comparative studies on corrosion protection properties of polyimide‐silica and polyimide‐clay composite materials

Comparative studies on corrosion protection properties of polyimide‐silica‐clay composites were studied in this article. A series of polyimide‐silica (PIS), polyimide‐clay (PIC), and polyimide‐silica‐clay composites (PISC) materials, consisting of an organo‐soluble polyimide (ODA‐BSAA) matrix, inorganic silica particles prepared through the sol–gel reaction of tetraethyl orthosilicate (TEOS) and dispersed nanolayers of inorganic montmorillonite clay, were successfully prepared by solution dispersion technique. Then, all samples were characterized by FTIR, powder X‐ray diffraction patterns, transmission electron microscopy, and ²⁹Si solid‐state NMR. The main focus of this article is the comparison of the corrosion protection properties of PIS, PIC, and PISC composite materials. Normally, the aspect ratio of clay is higher than silica. Superior dispersion of clay platelets into a polymer matrix may effectively increase the length of diffusion pathways for oxygen and water. The effects of the materials composition on the corrosion protection performance, gas barrier, and optical properties, in the form of both coating and film, were also studied by electrochemical corrosion measurements (e.g., corrosion potential, polarization resistance, corrosion current, and impedance spectroscopy), gas permeability analysis, and UV‐visible transmission spectroscopy. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Dielectric property of polyimide/barium titanate composites and its influence factors (II)

Using poly(amic acid) (PAA) as a precursor followed by thermal imidization, the polyimide/barium titanate composite films were successfully prepared by a direct mixing method and in situ process. The influence of processing factors, such as particle size, distribution mode and polymerization method on dielectric properties was studied. Results revealed that the dielectric constant (?) of the composite film increased by using bigger fillers or employing in situ polymerization and bimodal distribution. When the composite film containing 50 Vol-% of BaTiO₃ with size in 100 nm was prepared via in situ process, its dielectric constant reached 45 at 10 kHz.     

PP/无机粒子复合纤维吸附性能的研究

通过熔融共混和表面涂覆两种方法制备了不同种类的PP/无机粒子复合纤维 ,对其表面形态进行SEM观察 ,并应用自行设计的吸附装置对纤维的吸附性能进行分析。研究发现 ,PP/纳米粒子复合纤维的吸附性能明显优于PP/微米粒子复合纤维的吸附性能 ;而其中PP/纳米SiO2 复合纤维的吸附性能最好 ,吸附量较之于纯PP提高了 44 %。