一种低介电常数液体硅橡胶复合材料及其制备方法

一种低介电常数液体硅橡胶复合材料及其制备方法     

高介电常数高分子复合材料的研究进展

简要介绍了电介质材料的定义、特征及其极化机理,详细阐述了近年来铁电类陶瓷、金属粉末、碳类（石墨、炭黑、碳纤维）粒子填充的复合型聚合物基介电材料的研究和开发进展。在埋入式无源器件、印刷电路板等电子工业领域中,研究具有更高的介电常数、低损耗、耐高温、介电性能在宽广温度和频率范围内基本稳定的聚合物是该类聚合物基介电材料的发展方向。     

聚氨酯基高介电常数复合材料的制备与表征

采用聚氨酯弹性体（PU）为聚合物基体,超高介电常数的酞菁铜齐聚物（CuPc）为添加物,通过化学方法将CuPc接到PU链上,制备高介电常数复合材料。TEM结果显示,CuPc在PU中的分散性大大改善,颗粒尺寸约为20nm,约为CuPc和PU简单共混中CuPc粒径的1/25。颗粒尺寸的减小大大增强了复合体系中界面交换耦合效应...     

碳纤维增强硅橡胶复合材料制备

由于硅橡胶具有较好的耐热性但力学性能比较差,本文用高性能的碳纤维作增强剂,硅橡胶（MVQ）作基相及偶联剂作为相容剂制备了碳纤维/硅橡胶复合材料。通过力学性能和热老化测试,确定碳纤维的用量。用偶联剂作相容剂研究了偶联剂对硅橡胶和碳纤维相容性影响;通过傅里叶变换红外光谱（FTIR)和扫描电镜(SEM)分析了碳纤维和硅橡胶交联结构和相容性。结果显示,制备了碳纤维/硅橡胶复合材料的最佳配方为硅橡胶 100份,碳纤维 12份,KH-550 2.5份。碳纤维增强硅橡胶的最佳硫化条件为：温度 175℃,压力为10MPa,时间为30min。由扫描电镜和红外光谱分析,进一步论证了用KH-550处理的比没有处理及用Si69处理的碳纤维与硅橡胶的混合相容性好。     

碳纤维/硅橡胶复合材料的制备

以硅烷偶联剂为相容剂研制碳纤维/硅橡胶复合材料。最佳配方为硅橡胶100,白炭黑20,碳纤维12,偶联剂KH-550 2.5,三氧化二铁1,硬脂酸1,防老剂D 1,交联剂DCP 5,促进剂M 1;最佳一段硫化条件为175℃/10 MPa×30 min,最佳二段硫化条件为200℃(常压)×2 h。     

苯基硅橡胶纳米复合材料及其制备方法

<正>授权公告号:CN 104031388B授权公告日:2017年2月15日专利权人:上海大学发明人:谢云婷、高群、郭昀本发明涉及一种苯基硅橡胶纳米复合材料的制备方法。复合材料的配方为:苯基硅橡胶100,纳米填料1~5,催化剂1~5,固化剂1~10,表面活性剂0.06~0.3。复合材料     

CNTs/硅橡胶纳米复合材料导电性能的研究

采用超高速剪切分散的方法制备碳纳米管(CNTs)/硅橡胶纳米复合材料.试验结果表明,CNTs在复合材料中分散效果尚可;添加CNTs后,硅橡胶体积电阻率下降明显;与羟基化多壁CNTs相比,未羟基化多壁CNTs渗流阈值较小,对硅橡胶导电性能的提高作用较明显.     

高导热绝缘硅橡胶复合材料的制备方法

制备硅橡胶制品的方法和通过这种方法获得的产品     

硅橡胶基高导电复合材料的制备及其性能研究

以导电炭黑、片状微米银、碳纳米管为填料制备甲基乙烯基硅橡胶（MVQ）基高导电复合材料并研究其性能。结果表明：导电炭黑在MVQ中的逾渗阈值为8～12份（体积分数3.33%～4.92%）,导电炭黑用量为12份时导电炭黑/MVQ复合材料的交联网络最稳定;在添加12份导电炭黑的基础上添加150份片状微米银时,导电炭黑/片状微米银/MVQ复合材料在50%应变后的导电网络恢复程度最大;导电炭黑/片状微米银/碳纳米管/MVQ复合材料在50%应变后的电导率为1.2×104 S·m-1,电导率变化率为18%。     

石墨烯/硅橡胶导电复合材料的制备及性能研究

以甲基乙烯基硅橡胶(MVQ)为主体材料、石墨烯为导电填料,制备石墨烯/MVQ导电复合材料,研究石墨烯品种和用量对复合材料物理性能和导电性能的影响。结果表明:石墨烯LKR6963的剥离程度较高、片层较薄、缺陷较少,易在硅橡胶基体中形成导电网络,提高复合材料的导电性能;随着石墨烯LKR6963用量的增大,复合材料的硬度和拉伸强度明显增大,体积电阻率逐渐减小。     

高抗撕裂硅橡胶复合材料的制备

研究了羟基硅油和四甲基四乙烯基环四硅氧烷(V 4)对气相法白炭黑增强甲基乙烯基硅橡胶(VMQ)复合材料性能的影响。结果表明,在VMQ用量为100份、气相法白炭黑用量为40份时,加入羟基硅油可明显降低混炼胶的Payne效应,有效改善白炭黑的分散性;当其用量为5份时,复合材料的综合力学性能最优。在添加5份羟基硅油的基础上,加入V 4可显著提高VMQ复合材料的撕裂强度,其用量为4份时,撕裂强度可达42.2 k N/m。     

Effects of metal oxides on the dielectric and mechanical properties of silicone rubber composites

Polysiloxane dielectric elastomers have garnered a considerable deal of attention over the last decade due to their potential as electroactive soft materials. However, the intrinsic low dielectric constant of polysiloxanes has proven a serious limitation in their practical use. In this work, we controlled the dielectric properties of silicone rubber composites by changing the type and content of oxide fillers. The silicone-based dielectric elastomers with a high dielectric constant (5.21@1 kHz), low modulus (1.62 MPa), and high elongation (1100%) were successfully obtained. The effects of different types of metal oxides on the dielectric properties and mechanical properties of the prepared composites are further explored. Due to their excellent comprehensive features, these types of materials are expected to be applied in capacitive sensors, actuators, generators, and beyond.     

Influences of dielectric and conductive fillers on dielectric and mechanical properties of solid silicone rubber composites

Dielectric elastomers are materials being used for electromechanical transduction applications. Their electromechanical response depends on permittivity, Young’s modulus and electric breakdown strength. A factor that limits its application is high operating voltages that can be reduced through improvement in permittivity. One of the methods is by incorporating high permittivity fillers into polymer matrix to obtain dielectric–dielectric composites (DDC).These composites show high permittivity at the cost of reduced flexibility. An alternative solution is development of composites by incorporating organic or inorganic conductive fillers into polymer matrix. These composites show high permittivity with high dielectric loss and low breakdown strength. To overcome both the above limitations both dielectric and conductive fillers are incorporated into dielectric polymer matrix to obtain conductor–dielectric composites (CDC). In this study, high temperature vulcanized solid silicone rubber as matrix has been used to prepare DDC composites with barium titanate (BT) filler and CDC composites with both BT as dielectric and ketjenblack as conductive fillers, using Taguchi design of experiments. The effect of factors such as amount of fillers and curing agent, mixing time in roll mill and curing temperature on the dielectric and mechanical properties are reported. Lichtenecker model predicts the permittivity of the DDC composite more accurately. For the CDC composites permittivity increased by 390%, effective resistivity decreased by 80%, Young’s modulus increased by 368% and Shore A hardness increased by 90% as compared to those of reference matrix. Important interaction effects are observed among both the fillers that are uniformly dispersed without any aggregation.

     

Expanded graphite–epoxy composites with high dielectric constant

Composites of an expanded graphite/diglycidyl ether of bisphenol A (DGEBA) were prepared by a simple melt blending method, and their dielectric and mechanical properties were investigated. During observations of fractured surfaces of the composites, the graphite sheets were seen to be homogeneously dispersed in the epoxy matrix. Moreover, the composites presented an enhanced dielectric constant (～ 180) and a low loss factor (～ 0.05) at 50 Hz, suggesting their potential suitability for embedded dielectric applications. The enhanced dielectric constant can be explained by the percolation theory and the relatively low loss factor was attributed to strong interfacial interactions between the polymer molecules and the ? OH/? COOH groups of the expanded graphite, which constrained the orientational polarization of the polarons. Furthermore, dynamic mechanical analysis of the composites showed a restricted macromolecular relaxation and improved mechanical properties. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Improving properties of ceramic silicone rubber composites using high vinyl silicone oil

Reactive high vinyl silicone oil (HVSO) was selected to prepare the ceramic silicone rubber composites. The effects of HVSO on the mechanical properties and thermal stabilities of ceramic silicone rubber composites were investigated. The structures of the cross‐linked network of silicone rubber with or without HVSO were studied. The intermolecular space of silicone rubber was enlarged, and the cross‐linked point was concentrated by addition of HVSO, which was demonstrated by cross‐linking densities, scanning electron microscope (SEM) images, and dynamic mechanical analysis (DMA). The cross‐linked network model was formed with the slipping of the cross‐linked points along with the silicone rubber chain. Mechanical properties of composites were enhanced by the formation of this cross‐linked network. The tear strength, tensile strength, and elongation at break of the composites were increased by 18.5%, 13.2%, and 37.4% by the adding of 2 phr HVSO, respectively. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41864.     

Flexible and low cost lead free composites with high dielectric constant

Highly flexible lead free composite film having random distribution of ceramic filler was synthesized using Barium Titanate (BT) as a filler and inexpensive Thermoplastic Polyurethane (TPU) as a matrix. The results show that the 30 vol% BT-TPU composite has a dielectric constant of ~31 which is comparable to the expensive and difficult to produce PVDF based composites. With a breakdown field of 150 kV/mm, an energy density value of ~3 J/cm³ was estimated. These lead-free TPU based composites provide an alternative to PVDF based composites for energy storage applications.     

In situ preparation of polyimide/titanium carbide composites with enhanced dielectric constant

A series of polyimide/titanium carbide (PI/TiC) composites with different TiC contents were prepared using the ultrasonic dispersion and in situ polymerization method. Atomic force microscopy (AFM), X‐ray diffraction (XRD), scanning electron microscope (SEM), mechanical, and electrometer were used to characterize the structure and properties of the obtained composites. The morphological study of composites by AFM and SEM showed that TiC particles had a homogeneous dispersion in polyimide matrix with nanoscale at low filler dosage (≤10% volume content). X‐ray diffractions (XRDs) indicated that the doping of TiC slightly reduced the packing density of polyimide and destructed the aggregation structure of polyimide molecules. Experimental results showed that the obtained PI/TiC composites exhibited appropriate mechanical properties and moderate electric breakdown strength. Dielectric investigation evidenced that the dielectric constant and the dielectric loss of these composites increased with the increase of the volume fraction of TiC particles. The composite with 20 vol% TiC particles showed a highest dielectric constant of 37 while retaining an appropriate dielectric loss of 0.026, as compared with the dielectric constant (3–4) of neat polyimide resin. In addition, the dielectric properties of the composites displayed good stability within a wide range of frequency. The results of this work demonstrate the potential use of a PI/TiC composite film in an embedded capacitor. POLYM. COMPOS., 125–130, 2016. © 2014 Society of Plastics Engineers     

耐高温无卤阻燃硅橡胶的研究

以N,N-1,2-二乙基-双(1,3,5-三嗪-2,4,6-三胺)(ETT)为阻燃剂、硼酸锌和氧化锌为阻燃协效剂,制备耐高温无卤阻燃甲基乙烯基硅橡胶(MVQ)材料,并研究其阻燃性能、物理性能和耐热空气老化性能。结果表明,当阻燃剂ETT用量为56份、硼酸锌用量为3份、氧化锌用量为1份时,MVQ垂直燃烧级别达到FV-0,氧指数为38,综合物理性能和耐热空气老化性能均较好。     

Polyvinylidene fluoride-modified BaTiO3 composites with high dielectric constant and temperature stability

Polyvinylidene fluoride (PVDF)-modified X7R-type BaTiO₃ (BTO) composites were prepared by hot pressing, and the dielectric properties were investigated. The dielectric constant of the PVDF–BTO composites at 1 kHz increased significantly with increasing the volume fraction of BTO up to 0.5, and good temperature stability of dielectric constant was obtained for the composites, which benefited from the temperature-stable dielectric constant of the modified BaTiO₃. Two significant dielectric relaxations were observed for the PVDF–BTO composites, and they fit the Vogel–Fulcher and Arrhenius fittings, respectively.     

Correction to: Influences of dielectric and conductive fillers on dielectric and mechanical properties of solid silicone rubber composites

Iranian Polymer Journal - The article listed above was initially published with incorrect Table&nbsp;1 and Table&nbsp;2 values.