聚苯胺改性0-3 型PZT/ 聚氨酯复合材料的极化与电性能

以聚苯胺( PANI) 原位聚合改性聚氨酯( PU) 树脂为基体, 锆钛酸铅( PZT) 陶瓷为功能相, 制备了0-3 型压电复合材料, 研究了复合材料极化和电性能。结果表明: 适量PANI 能够有效地提高0-3 型复合材料的极化和压电性能。随着PANI 含量增加, 复合材料的压电系数d33和机电耦合系数kp 迅速增大。当PANI 体积分数为4 %时, 复合材料的d33 = 34 pC/ N , kp = 0.25 , 均达到最大值。复合材料的介电常数和介电损耗随PANI含量的增加而上升。      

柔性智能聚苯胺/聚氨酯导电纳米纤维的制备及性能

利用静电纺丝技术制备聚氨酯(PU)纳米纤维,采用原位聚合法在纤维表面聚合导电聚合物聚苯胺(PANI),得到具有优良导电性能的柔性PU/PANI复合纳米导电纤维。通过扫描电镜观察到表面均匀包覆聚苯胺的复合纳米纤维;红外光谱结果证明在聚氨酯纳米纤维表面成功合成了聚苯胺。通过实验可知,聚苯胺最佳聚合工艺为苯胺单体浓度为1.3 mol/L、聚合时间为120 min。导电性能测试发现,PU/PANI复合纳米纤维导电性能优良,电导率可达7.6×10-1S/cm,经聚合后力学性能较为稳定。将PU/PANI导电纳米纤维制成简易柔性传感器件,探究发现PU/PANI导电纳米纤维具有柔性应变电学性质,且反应灵敏。     

PANI/Ce(OH)_3-Pr_2O_3·3H_2O/NanoG复合材料的热稳定性及导电性

采用一种制备纳米复合材料的新方法——反胶束模板-原位聚合一步法成功地制备了PANI/Ce(OH)3-Pr2O3.3H2O/NanoG复合材料,并系统研究了其热稳定性及导电性能。测试结果表明,该复合材料的热稳定性较纯聚苯胺(PANI)有了明显的提高;石墨纳米薄片(NanoG)的特殊的结构(较大的径厚比)对其在聚合物基体中形成导电网络具有重要作用;PANI/Ce(OH)3-Pr2O3.3H2O/NanoG复合材料的渗滤阀值低于1.0%。     

压电陶瓷/聚合物基新型阻尼复合材料的研究进展

压电陶瓷/聚合物基复合材料兼具了聚合物和压电陶瓷两相的优点,是新型的智能阻尼材料.叙述了压电陶瓷/聚合物基复合材料的阻尼性能表征、阻尼原理以及影响阻尼性能的主要因素,并展望了研究前景.指出从压电阻尼材料的基础理论、制备工艺和性能表征、结构与性能关系上寻找突破,可以获得可控的高阻尼压电复合材料.     

以石墨烯气凝胶为导电相的压电阻尼复合材料

阻尼材料在减振降噪领域有着极其重要的应用,而压电阻尼复合材料能够在普通阻尼材料摩擦损耗基础之上进一步引入力-电-热损耗,从而提高基体材料的阻尼性能,使其在主动和被动减震方面备受青睐。但是通常为了达到导电渗流阈值,需要添加大量的导电相。采用模板辅助氧化石墨烯自组装的方式制备了三维石墨烯气凝胶,以此作为导电相,以聚氨酯/聚甲基丙烯酸丁酯/聚甲基丙烯酸甲酯IPN共聚物作为基体,锆钛酸铅压电陶瓷作为压电相,制备了压电阻尼复合材料。三维石墨烯气凝胶的使用,由于其本身三维导电网络的存在,使得制备的压电阻尼复合材料可以在很低的导电相含量下达到导电渗流阈值,将压电陶瓷产生的电能转化为热能损耗掉,有效拓宽了基体材料的阻尼温域和提高了材料室温下的阻尼性能。     

壳聚糖/聚乙烯醇复合纳米导电纤维的制备及性能表征

以壳聚糖(CS)、聚乙烯醇(PVA)和纳米石墨粉(G)为原料,利用静电纺丝技术分别制备了壳聚糖/聚乙烯醇共混纳米纤维及壳聚糖/聚乙烯醇/纳米石墨粉复合纳米纤维,采用原位聚合法在纤维表面聚合导电聚合物聚苯胺,得到具有优良导电性能的聚合CS/PVA和聚合CS/PVA/G复合纳米纤维。通过扫描镜、X射线衍射、红外光谱等测试手段对纤维的形貌和结构进行表征。结果表明,聚苯胺均匀包覆在经原位聚合的复合纳米纤维表面,提高了纤维的导电性能,纳米石墨粉与聚苯胺形成插入化合物进一步提高了纤维的导电性能。     

碳纳米管/导电聚苯胺复合材料的制备及相互作用研究进展

综述了近年来通过原位聚合法和化学共价法制备碳纳米管/导电聚苯胺复合材料的最新研究进展,并且重点分析了碳纳米管、聚苯胺之间的相互作用.与原位聚合法相比,化学共价法制备的碳纳米管/导电聚苯胺分子间除了π-π相互作用外,还存在着强烈的化学键作用,能够显著提高导电聚苯胺的热稳定性,同时,导电聚苯胺可提高官能化碳纳米管的电化学氧化还原稳定性.     

压电陶瓷/CIIR复合材料的阻尼性能的研究

以氯化丁基橡胶(CIIR)及其互穿网络为基体,加入压电陶瓷PMN和导电炭黑CB制备PMN/CB/CIIR复合材料,系统研究其的阻尼性能的影响因素以及机理,以获得高介电常数和高阻尼性能的压电陶瓷/聚合物基复合材料,拓展其在介电材料和阻尼材料领域的应用。     

原位聚合法制备PANI/EP导电防腐蚀涂层

传统方法制备的聚苯胺防腐蚀导电涂层,聚苯胺易下沉,使涂层电导率差.为此,借用原位聚合方法制备了聚苯胺/环氧树脂(PANI/EP)复合防腐蚀涂层.利用相应的性能测试方法检测和比较了不同反应条件下(如苯胺单体用量、引发剂的用量、酸量、聚合时间)合成的聚苯胺复合涂层的导电性能,并将其与传统方法制备的涂层进行了比较.结果表明:降低了氧化剂、酸的用量;因为降低了聚苯胺的粒径而减轻了聚苯胺粒子在涂层中的下沉,从而提高了涂层的导电性能,电导率达到1.6×10-2S/m.     

本征态聚苯胺/聚丙烯驻极体复合过滤材料的制备与性能

为研究本征态聚苯胺对非织造过滤材料的驻极性能和过滤性能的影响,制备具有良好性能的非织造复合材料。采用原位聚合法制备了本征态聚苯胺/聚丙烯(PANI/PP)复合材料,通过SEM扫描电镜对复合材料的表面形态进行了表征,测试分析及比较本征态聚苯胺/聚丙烯(PANI/PP)复合材料和PP材料电晕驻极后的表面静电势和电荷储存性能及过滤性能。实验结果表明,本征态聚苯胺/聚丙烯(PANI/PP)复合材料具有较好的驻极性能,本征态聚苯胺(PANI)能够大幅提升聚丙烯(PP)材料的表面静电势,同时在最佳驻极条件下本征态聚苯胺/聚丙烯(PANI/PP)复合材料比聚丙烯(PP)材料的电荷储存性能更加稳定,电荷保留率为60%左右,且过滤效率高出20%左右。     

Damping behavior and acoustic performance of polyurethane/lead zirconate titanate ceramic composites

0–3 Type PU-based lead zirconate titanate ceramic (PZT) composites are prepared by in situ polymerization method, this PU/PZT composite material has excellent sound absorption property at low frequencies because of damping property and piezoelectric property. The dispersion of PZT particles in PU matrix, dielectric loss tangent (tan δ), dynamic storage modulus (E′), dynamic loss modulus (E″), and the acoustic absorption coefficient (α) of PU/PZT composites are studied by scanning electron microscopy (SEM), dynamic mechanical analysis (DMA) and two-microphone impedance tube, respectively. The results indicate that the modified PZT particles dispersed well in PU matrix with the content of 30 wt%; the tan δ, E′ and E″ are 0.62, 3.75 GPa and 6.05 GPa, respectively, when the composite with 30 wt% of polarizing PZT; the acoustic absorption coefficient is found to increase with an increase of PZT content, and the average acoustic absorption coefficient is 0.32 at low frequencies from 125 to 500 Hz.     

0-3型橡胶基压电阻尼复合材料的制备及其性能

本文以通用橡胶为基体材料,以一定体积分数的锆钛酸铅粉体（PZT）为压电相、导电炭黑为导电相制备了0-3型压电阻尼复合材料。经过直流高温油浴极化处理后,获得了在低频下具有较高损耗因子的压电阻尼材料,并研究了其断面形貌、压电应变系数、损耗因子等各项性能。     

Mechanisms in damping of mechanical vibration by piezoelectric ceramic-polymer composite materials

The piezoelectric ceramic (piezoceramic) component of a polymer-piezoelectric ceramic composite converts mechanical energy into electrical energy and this electrical energy is dissipated as heat in a load resistance, R _x, simulated by a shunted resistance, but provided in practice by a conductive polymer composite matrix. The composite therefore dissipates the input mechanical energy via the damping mechanism provided by piezoelectric ceramic-conductive matrix material, as well as the conventional viscoelastic damping provided by the polymer. Mathematical models have been developed to characterize the damping behaviour of the composites, and the maximum damping ratio of composites can be as high as 23%. A two degrees-of-freedom (2DOF) experimental setup was developed to test the validity of the models. The experimental results are in good agreement with the theoretical predictions.     

Optimized pyroelectric properties of 0-3 composites of PZT particles in polyurethane doped with lithium perchlorate

A substantial improvement in the performance of pyroelectric 0-3 composites of ceramic particles in a polymer matrix has been achieved by doping the polymer matrix material. Readily prepared and polarized films with various volume fractions of lead zirconate-titanate (PZT) particles in polyurethane have been doped in a solution of lithium perchlorate in acetone to increase the conductivity. With an appropriate conductivity, the dielectric permittivities of the ceramic particles and the polymer matrix become matched, resulting in an improvement of the pyroelectric coefficient from about 6 microC/(m(2)K) to about 50 microC/(m(2)K). The experimental results are explained by theoretical predictions.     

压电陶瓷粒度分布对锆钛酸铅/聚偏氟乙烯复合材料电性能的影响

将不同粒度的锆钛酸铅(PZT)陶瓷粉进行复配,制成不同粒度分布的PZT陶瓷颗粒,然后与聚偏氟乙烯(PVDF)复合制备不同PZT粒度分布的PZT/PVDF复合材料,研究了复合材料的介电性能和压电性能。结果表明,当陶瓷颗粒体积分数高达70%时,双峰分布复合材料的压电系数可达75 pC·N-1。这是由于双峰分布复合材料中大陶瓷颗粒保持了完整的钙钛矿结构,小陶瓷颗粒填充在大颗粒之间,陶瓷颗粒彼此联接,形成了更多的电-力耦合通道,有效地实现了压电效应的传递。大陶瓷颗粒完整的钙钛矿结构以及大、小颗粒的协同堆砌效应,提高了PZT/PVDF复合材料的电性能。     

基于ANSYS的0-3型压电复合材料电荷分布

通过MATLAB软件对陶瓷颗粒均匀分布的0-3型压电陶瓷/聚合物复合材料进行了建模, 通过有限元分析软件ANSYS, 研究了压电复合材料受力时内部应力分布及电荷分布状态, 同时研究了压电陶瓷颗粒体积分数及静态载荷变化时, 压电陶瓷/聚合物复合材料中压电陶瓷产生的最大节点电压的变化情况。研究表明: 压电陶瓷/聚合物复合材料在受力时, 压电相受到的应力远远大于聚合物相, 压电相棱角处受到的应力最大, 产生的电荷最多。随着压电陶瓷体积分数变化, 压电复合材料中压电陶瓷产生的最大节点电压也增加, 当压电陶瓷体积分数达到30%时, 产生的最大节点电压达到2.86×10^-5 V。随着静态载荷的增加, 压电复合材料产生的最大节点电压呈线性增加, 阻尼效果越明显, 与文献中的实验结果吻合。     

O-3型压电陶瓷/聚合物复合材料的制备工艺新进展

0－3型压电陶瓷／聚合物复合材料具有单相压电陶瓷或聚合物所不具备的良好的综合性能,因此引起了人们广泛的兴趣和研究。本文综述了0－3型压电复合材料的制备工艺及相应复合材料的压电性能,重点介绍了水解－聚合法、凝聚－胶体法、溶液聚合法3种新型制备工艺,简要分析各种制备工艺的优缺点,为压电陶瓷／聚合物复合材料（甚至是纳米级压电复合材料）的进一步研究、开发和应用提供依据。     

0—3型压电陶瓷—聚合物复合材料的制备与压电性

采用电陶瓷锆钛酸铅粉末掺入聚合物基聚偏二硫乙烯的方法，制备了柔性压电复合材料ＰＺＴ－ＰＶＤＦ。本文报导了这两种复合材料的制备工艺及其介电性和压电性，并讨论了在水听器方面的应用。     

A novel in-situ polymer derived nano ceramic MMC by friction stir processing

Friction stir processing (FSP) is a solid state technique used for material processing. Tool wear and the agglomeration of ceramic particles have been serious issues in FSP of metal matrix composites. In the present study, FSP has been employed to disperse the nanoscale particles of a polymer-derived silicon carbonitride (SiCN) ceramic phase into copper by an in-situ process. SiCN cross linked polymer particles were incorporated using multi-pass FSP into pure copper to form bulk particulate metal matrix composites. The polymer was then converted into ceramic through an in-situ pyrolysis process and dispersed by FSP. Multi-pass processing was carried out to remove porosity from the samples and also for the uniform dispersion of polymer derived ceramic particles. Microstructural observations were carried out using Field Emission Scanning Electron Microscopy (FE-SEM) and Transmission Electron Microscopy (TEM) of the composite. The results indicate a uniform distribution of ~ 100 nm size particles of the ceramic phase in the copper matrix after FSP. The nanocomposite exhibits a five fold increase in microhardness (260HV₁₀₀) which is attributed to the nano scale dispersion of ceramic particles. A mechanism has been proposed for the fracturing of PDC particles during multi-pass FSP.     

New type of mechanical damping composites composed of piezoelectric ceramics,carbon black and epoxy resin

New types of piezoelectric damping materials, piezoelectric ceramic (PZT) powder/carbon black (CB) powder/epoxy (EP) resin composites, were developed, and their mechanical and damping properties were studied. Here the mechanical energy of vibrations and noises were transformed into electric energy (current) by PZT, and the electric current was conducted to an external circuit through CB powders and then dissipated as thermal energy through a resistor. When CB was added to PZT/EP (70/30 in wt%), the mechanical loss factor (η), a measure of mechanical of damping intensity, showed a maximum value of ∼0.08 at the CB content of ∼0.51 wt%, at which the CB particles electrically just contact each other. In the present work, it was found that the PZT/CB/EP composite of 90.0/0.5/9.5 shows a large η value of ∼0.15.