高储能密度PI基纳米复合材料研究进展

综述了采用溶液共混法、原位聚合等方法将纯聚酰亚胺(PI)与各类功能性填料进行掺杂。分别概述了陶瓷、纳米碳材料等填料填充制备的PI基介电纳米复合材料,极大地提升了复合材料的介电储能性。对近年来国内外PI基复合材料体系、制备方法及其介电性能的研究进行了系统的综述,对其研究和应用趋势进行了展望。     

钙长石／玻璃复合材料的制备和性能研究

采用电子陶瓷工艺制备了一系列钙长石／玻璃复合材料,并对复合材料进行X射线分析、扫描电镜观察和性能测试。结果表明：复合材料的介电常数、热膨胀系数随钙长石含量的增加而增加,而介电损耗和抗折强度随钙长石含量的增加而减小。钙长石含量大于50wt％的复合材料中α-石英和方石英的析出增加了材料的热膨胀系数,但对材料的介电性能影响不大。所制备的复合材料具有低的介电常数（5．4～6．1）、低的介电损耗（0．11％～0．41％）、低的热膨胀系数（4．3×10^-6～6．1×10^-6／℃）和低的烧结温度（≤900℃）,有望用于电子封装领域。     

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。     

聚酰亚胺/纳米钛酸钡复合薄膜的制备与表征

制备了一系列聚酰亚胺及其钛酸钡复合薄膜,并采用了XRD,IR等分析手段分析了复合薄膜的形貌和性能。主要研究内容如下:(1)采用水热法制备钛酸钡粉体;（2）分别用溶液混合法和原位聚合法制备PI/BT纳米复合薄膜。经分析可知,复合膜中钛酸钡粒子较为均匀地分散在聚酰亚胺基体中,并且复合膜的介电性能随钛酸钡粒子含量的增加而增加。在33%（钛酸钡的质量分数）1KHz频率时,制备的复合薄膜介电常数可达35,使其具有广泛的应用前景。     

聚酰亚胺/钛酸钡复合薄膜的制备及性能

将钛酸钡(BT)粒子与聚酰胺酸溶液共混,亚胺化后得到聚酰亚胺(PI)包覆的BT(PI@BT)粒子.分别以BT粒子和PI@BT粒子为改性填料,通过原位聚合法制备了PI/BT和PI/PI@BT复合薄膜,对比了两种复合薄膜的结构与性能.结果表明:PI@BT粒子具有明显的核壳结构,较BT在PI基体中分散更均匀,从而有效地提高了...     

高介电聚酰亚胺复合材料的制备及应用

随着电子工业的不断发展,传统的聚酰亚胺材料作为电子电工领域应用较多的绝缘介质材料,人们对其综合性能要求也越来越高.目前,聚酰亚胺的复合材料在生活领域中广泛应用,有关高介电常数的聚酰亚胺复合材料薄膜的研究也越来越多.不同类型的线性电介质、导电填料、介电陶瓷加入聚酰亚胺基体,可以得到介电常数不同的聚酰亚胺复合材料.本文列举...     

俄罗斯研究聚酰亚胺／纳米碳纤维复合材料

聚酰亚胺纤维是耐热性良好的高分子材料。它具有多种优越的物理性能,在航空航天、防辐射材料、耐高温耐化学材料领域,是很受青睐的高科技纤维之一．俄罗斯高分子化合研究院试验用聚酰亚胺结晶、纳米碳纤维、碳微纤维制造复合材料（碳塑料）。     

Cardo基低介电聚酰亚胺的合成及性能

以9,9-双(4氨基苯基)芴、对苯二胺、3,3′,4,4′-联苯四羧酸二酐为原料成功制备了一系列含联苯芴(Cardo)基的低介电聚酰亚胺,并表征了其各项性能。通过红外吸收光谱证明了聚酰亚胺的亚胺化程度,X射线衍射(XRD)表征了材料的聚集态结构,材料的分子间距随着Cardo基引入而变大;通过热重分析(TG)和动态热机械分析(DMA)表征了材料的热性能,结果表明,随着分子链中Cardo基含量的增加,玻璃化转变温度从340℃增加到372℃,1%的失重温度从568℃降低到507℃;通过分子模拟表明,大侧基效应导致自由体积增大,分子自由度减弱。介电测试表明,在1 MHz条件下,随着Cardo基含量的增加,介电常数从3.56降低到3.37,介电损耗从0.019降低到0.015。力学性能测试表明,Cardo基引入,材料变脆,拉伸模量和断裂伸长率下降较明显。     

Preparation and properties of high-strength-high-modulus polyimide cords/natural rubber composites

High-strength-high-modulus polyimide (PI) cords reinforced natural rubber (NR) composites are prepared, and the PI cords are treated with resorcinol-formaldehyde-latex (RFL) adhesive to enhance the interfacial adhesion with NR matrix. The influence of RFL adhesive variables, such as the ratio of R/F and RF/L, on the adhesion between PI cords and NR is investigated. Furthermore, sorbitol glycidyl ether (SGE) and caprolactam blocked methylene diisocyanate (CBI) are adhered to the surface of the PI cords through a dip-coating procedure to introduce epoxy and NCO groups and graft with more RFL adhesive. The H pull-out force of SGE/CBI-RFL treated PI cords/NR composites reaches as high as 193.9 N, which is 580% higher than that of untreated PI ones. Additionally, the SGE/CBI-RFL treated PI cords/NR composites exhibit superior adhesion, aging, and fatigue resistance together with better mechanical properties as compared with SGE/CBI-RFL treated poly(para-phenylene terephtalamide) (PPTA) cords/NR composites.     

反式聚异戊二烯/纳米碳化硅形状记忆复合材料的制备与性能

以反式聚异戊二烯（TPI）为基质,研究了纳米碳化硅用量对碳化硅/TPI形状记忆复合材料硫化特性、物理机械性能、热性能及形状记忆性能的影响。结果表明,随着碳化硅用量的增加,复合材料的焦烧时间和正硫化时间都逐渐缩短;拉伸强度呈现先增大后减小的趋势,硬度逐渐增大;结晶度逐渐降低,从纯TPI的16.5%下降至碳化硅用量20份（质量,下同）时的13.9%;碳化硅用量为10份时复合材料的单向形状记忆性能最好,而其双向形状记忆行为在应力为250 kPa时的形状回复率达到了最大值79.1%。     

Preparation and the properties of PMR‐type polyimide composites with aluminum nitride

A new polyimide composite was developed relying on the concept of in situ polymerization of monomer reactants polyimide. High thermal conductive, low dielectric constant and dielectric loss, and thermal‐stable composites were successfully demonstrated by incorporating aluminum nitride powder into the polyimide. The weight percent of aluminum nitride was up to 80%. The thermal and dielectric properties follow the classic composite theories. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 3913–3917, 2003     

Dielectric properties and energy-storage performance of two-dimensional molybdenum disulfide nanosheets/polyimide composite films

Flexible dielectric materials with high electric energy density and high-temperature resistant characteristic are of great importance for modern electronics and electrical systems. Herein, two-dimensional molybdenum disulfide (MoS₂) nanosheets were efficiently produced via liquid-phase exfoliation and then incorporated into polyimide (PI) to prepare MoS₂/PI dielectric nanocomposites. Compared to the pristine PI, MoS₂/PI nanocomposite films exhibited much larger dielectric permittivity while their dielectric losses still maintained relatively low levels. On the other hand, the Weibull breakdown strength of these nanocomposite films initially increased and then decreased with the increase in the MoS₂ content and gave rise to a maximum value of 395 MV m⁻¹ at 1 vol % loading. Combination of the improved dielectric permittivity and breakdown strength makes the MoS₂/PI nanocomposite film with 1 vol % MoS₂ possess an elevated energy density of about 3.35 J cm⁻³. Moreover, good tensile and thermal properties of the nanocomposite films hold great promise for their applications in high-temperature and harsh conditions. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47991.     

碳纤维增强碳化硅基复合材料的研究

碳纤维增强碳化硅基复合材料(Cf/SiC)具有良好的力学性能,作为特殊结构的功能材料,是航空航天领域和新能源领域的研究热点之一。本文主要阐述了增强相碳纤维的发展,复合材料的基体复合技术,以及复合材料界面相的研究,并展望了碳纤维复合材料在高新技术领域中的应用与发展前景。     

Influence of silicon carbide filler on mechanical and dielectric properties of glass fabric reinforced epoxy composites

Fiber‐reinforced polymeric composites (FRPCs) have emerged as an important material for automotive, aerospace, and other engineering applications because of their light weight, design flexibility, ease of manufacturing, and improved mechanical performance. In this study, glass‐epoxy (G‐E) and silicon carbide filled glass‐epoxy (SiC‐G‐E) composite systems have been fabricated using hand lay‐up technique. The mechanical properties such as tensile strength, tensile modulus, elongation at break, flexural strength, and hardness have been investigated in accordance with ASTM standards. From the experimental investigations, it has been found that the tensile strength, flexural strength, and hardness of the glass reinforced epoxy composite increased with the inclusion of SiC filler. The results of the SiC (5 wt %)‐G‐E composite showed higher mechanical properties compared to G‐E system. The dielectric properties such as dielectric constant (permittivity), tan delta, dielectric loss, and AC conductivity of these composites have been evaluated. A drastic reduction in dielectric constant after incorporation of conducting SiC filler into epoxy composite has been observed. Scanning electron microscopy (SEM) photomicrographs of the fractured samples revealed various aspects of the fractured surfaces. The failure modes of the tensile fractured surfaces have also been reported. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Preparation of aluminum/silicon carbide metal matrix composites using centrifugal atomization

This paper describes the development of a new technique to produce metal matrix composites (MMCs) by injecting silicon carbide particles into molten aluminum just prior to centrifugal atomization. A centrifugal atomization apparatus has been constructed for this study. Silicon carbide particles are injected during atomization of 6061 aluminum alloy to form metal matrix composite powder. The prepared aluminum/silicon carbide powder contains 18 vol.% of SiC particles and 1.2 vol.% of voids. The particle grain size is almost independent from the particle size.     

Preparation of diamond/SiC composites by the liquid silicon infiltration method and their microstructure and properties

Diamond/SiC composites have long been recognized as advanced materials for thermal management as they exhibit excellent thermal and mechanical properties. The objective was to investigate and understand the phase composition, diamond graphitization behavior, microstructure, and properties of diamond/SiC composites developed following the liquid silicon infiltration process. The results revealed that the incorporation of α-SiC particles increased the degree of uniformity of the microstructure of the diamond/SiC composites. The acoustic mismatch model was used to analyze the samples before and after diamond graphitization to evaluate the interfacial thermal resistance of the composites. The results indicated that the interfacial thermal resistance of the graphitized composites was 11.9 times higher than the interfacial thermal resistance of the un-graphitized composites. Finally, the correlation between the diamond content of the composites and their thermal and mechanical properties was investigated.     

Preparation and properties of layered silicate/polyimide hybrid films

Layered silicate/polyimide (PI) hybrid films were prepared from 4,4′‐oxydianiline, 3,3′,4,4′‐oxydiphthalic anhydride, and chemically modified montmorillonite via an in situ intercalation polymerization pathway. The X‐ray diffraction and transmission electron microscopy results indicated that the silicates were homogeneously dispersed as exfoliated layers in the PI hybrid film with 2% silicate. The mechanical properties and thermal stabilities of the PI hybrid films changed with the content of the layered silicates. The coefficient of thermal expansion and water uptake of the PI hybrid films decreased with increasing silicate contents because of the barrier effect of platelike silicate layers, which prevented the diffusion and penetration of water. The dielectric strength and electrical aging performance of the PI hybrid films could also be improved as the silicate layer highly dispersed in the films. For the hybrid PI film with 5% layered silicate, the time to failure during electrical aging exceeded 280 h, which was 2.5 times as long as that of pure PI film. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1176–1183, 2005     

多壁碳纳米管/聚酰亚胺复合材料制备及其性能研究

聚酰亚胺的前聚体,聚酰胺酸,是通过4,4-二氨基二苯醚(ODA)与3,3,4,4二苯甲酮四羧酸二酐(BTDA)反应制备的.未改性的、酸改性和胺改性的多壁碳纳米管(MWCNT)被分别地单独加入到聚酰胺酸溶液中,并加热至300℃,从而制成聚酰亚胺/碳纳米管复合材料.扫描型电子显微镜(SEM)和透射电子显微镜(TEM)的显微...