PU/CB/PZT压电阻尼复合材料极化条件的研究

以导电碳黑(CB)为导电相、压电陶瓷(PZT)为压电相、聚氨酯(PU)为基体制备了一系列的压电阻尼复合材料(PU/CB/PZT)。研究了CB、PZT对所制备材料的耐击穿性能的影响,探讨了材料的压电性能和阻尼性能随PZT含量以及极化时间的变化规律。结果表明,PU/CB/PZT压电阻尼复合材料的压电常数随PZT含量和极化时间增加而增加,当极化场强选为5 kV/mm、极化时间30 min、PU/CB/PZT质量份为100/4/80时,材料的压电性能最佳,达到45.7 PC/N。随着PZT用量和极化时间增加,压电阻尼复合材料的阻尼因子峰值提高。     

压电陶瓷PZN-PZT对压电复合材料性能的影响

本研究采用固相烧结法合成了PZN-PZT压电陶瓷粉体,并用XRD分析了其晶相组成。将PZN-PZT陶瓷粉体与PVDF复合,制备出PZN-PZT/PVDF0-3型压电复合材料,研究了陶瓷质量分数对复合材料铁电性、介电性及压电性的影响。结果表明,复合材料的铁电性、介电性和压电性能随陶瓷含量的增加而增强,当陶瓷含量为90%时,复合材料的剩余极化强度Pr达到5.27μC·cm-2,矫顽场EC为76kV·cm-1,介电常数εr为188,介电损耗tanδ为0.065,压电常数d33则达到33.4pC/N。     

压电陶瓷/NBR复合材料阻尼性能研究

采用机械共混法制备压电陶瓷/NBR复合材料,并对其拉伸性能和阻尼性能进行研究.结果表明,当压电陶瓷用量为200份时,复合材料的拉伸性能和阻尼性能较好;极化可提高复合材料的阻尼性能;随着外加交变作用力的增大,极化后的复合材料阻尼性能提高.     

聚氨酯/钛酸铜镧钠复合材料的制备及介电性研究

采用溶胶-凝胶法制备了钛酸铜镧钠Na_(0.5)La_(0.5)Cu_3Ti_4O_(12)(NLCTO)陶瓷粉末填料。以聚氨酯(PU)材料为基体,采用原位聚合方法,制备了PU/NLCTO复合材料。利用红外光谱仪、X射线衍射仪、扫描电子显微镜、阻抗分析仪对复合材料的结构和性能进行了研究。结果表明:随着NLCTO陶瓷粉体含量增加,复合材料的介电常数和电导率相应地增大,但其介电损耗在一定的频率范围内变化不大。当NLCTO质量分数达到30%时,复合材料的介电常数在100 Hz下达到64.5,是聚氨酯基体的5倍;在10 k Hz下达到22,是聚氨酯基体的7.5倍。     

阻尼赋予剂对丁苯橡胶/再生橡胶并用胶性能的影响

研究阻尼赋予剂[锆钛酸铅压电陶瓷(PZT)、石墨、氧化锌晶须]对丁苯橡胶/再生橡胶并用胶性能的影响,胶料阻尼性能在振动仿真试验机上测试。结果表明:当振动频率为10Hz时,胶料的阻尼性能稳定;随着振动时间延长,添加不同阻尼赋予剂的胶料阻尼性能均有不同程度降低;添加阻尼赋予剂的胶料阻尼性能、加工安全性能和物理性能均有所提高;PZT胶料的阻尼性能最好,PZT的用量以3份为宜。     

陶瓷粉体粒度对PZN—PZT／PVDF压电复合材料性能的影响

将铌锌锆钛酸铅（PZN—PZT）压电陶瓷粉体分散于聚偏二氟乙烯（PVDF）基体中,制备出0-3型PZN—PZT／PVDF压电复合材料。文中研究了PZN—PZT陶瓷不同粒度对复合材料的压电性、介电性、铁电性的影响。结果表明,当陶瓷粒度为100～150目时,压电复合材料的综合性能最佳,压电常数d33达到23．10pC／N,剩余极化强度Pr达到5．131μC·era2,矫顽场Ec为45．7lkV·cm^-1,介电常数ε。为192．86,介电损耗tanδ为0．10。     

复合工艺对压电复合材料性能的影响

采用直接混合和溶液混合两种不同的复合工艺,将铌锌锆钛酸铅（PZN—PZT）压电陶瓷粉体分散于有机聚偏二氟乙烯（PVDF）基体中,制备了0—3型PZN—PZT／PVDF压电复合材料。研究了复合工艺对压电复合材料性能的影响。结果表明,采用溶液混合法能有效地改善陶瓷的分散性及复合材料的压电性,当陶瓷质量分数为90％时,压电复合材料的压电常数d33达到33．4pC·N^-1。     

氟橡胶基压电复合材料的性能研究

试验研究导电炭黑用量、压电陶瓷用量和极化条件对氟橡胶基压电复合材料性能的影响.结果表明,当导电炭黑用量为30份、压电陶瓷用量为60份、极化温度为100℃、极化电压为7.5 kV、极化时间为30 min时,压电复合材料不仅保持了一定的物理性能,还具有良好的压电性能.     

受阻酚AO-80/混炼型聚氨酯复合材料的制备及阻尼性能研究

在混炼型聚氨酯(MPU)中加入受阻酚AO-80制备AO-80/MPU复合材料,并对其性能进行研究。结果表明:受阻酚AO-80与MPU的热力学相容性良好;随着受阻酚AO-80用量的增大,受阻酚AO-80/MPU复合材料的玻璃化温度逐渐向高温方向移动;与纯MPU相比,复合材料的损耗因子最大值增大,有效阻尼温域拓宽,物理性能下降,阻尼性能明显提高;当受阻酚AO-80用量为40份时,复合材料的阻尼性能和综合物理性能良好。     

成瓷助剂对陶瓷化聚烯烃复合材料性能的影响

以乙烯-乙酸乙烯酯共聚物(EVA)和乙烯-1-辛烯共聚物(POE)为基体树脂,低熔点玻璃粉为助熔剂,陶瓷粉为成瓷填料,制备了陶瓷化聚烯烃复合材料,研究了成瓷助剂添加量对复合材料力学性能、电绝缘性能及耐火性能的影响。结果表明：低熔点玻璃粉的加入提高了复合材料的力学性能和击穿场强,体积电阻率略微下降,介电常数变化不大;随着陶瓷粉添加量的增加,复合材料的力学性能先提高后降低,体积电阻率先增大后减小,电气强度提高;成瓷助剂的加入可以提高复合材料燃烧残余物的稳定结构。     

聚氨酯基压电阻尼复合材料阻尼性能的研究

用绝缘电阻测试仪研究了以聚氨酯(PPG2000)为基体材料,锆钛酸铅(PZT)为压电填料,导电炭黑(CB)为导电填料的压电复合阻尼材料的导电性能。以渗流理论分析了对于PPG2000导电炭黑的渗流阈值,以及PZT的加入对导电炭黑渗流阈值的影响。采用动态力学性能分析(DMA)技术对聚氨酯压电陶瓷复合阻尼材料的阻尼性能进行研究,分析了导电性能对其阻尼性能的影响。     

Design and properties 1–3 multi-element piezoelectric composite with low crosstalk effects

Piezoelectric composites are gaining increasingly importance in ultrasonic fields due to their superior properties. Here novel 1–3 multi-element piezoelectric composites were developed by using piezoelectric ceramic as functional phase, epoxy resin as matrix phase, and silica gel and polyurethane as decoupling materials. The effects of decoupling materials and composite thickness on dielectric, piezoelectric and electromechanical coupling properties of the composites were investigated. The coupling response among various elements of the composites was discussed by setting up an ultrasonic testing platform. The results show that the multi-element piezoelectric composites have larger piezoelectric voltage factor than piezoelectric ceramic, however, less relative permittivity and piezoelectric strain factor. With decreasing the composite thickness, the thickness resonant peaks of the piezoelectric composite shift toward high frequency direction, and no obvious high-order and coupling resonant peaks appear. The multi-element piezoelectric composites have larger thickness electromechanical coupling coefficient k_t and less mechanical quality factor Q_m than piezoelectric ceramic. When composite thickness is 5 mm, the epoxy/silica piezoelectric composite has a maximum k_t value of 70.41%, and a minimum Q_m value of 11.29. The coupling response testing results show that epoxy/silica piezoelectric composite shows less crosstalk effect than epoxy/epoxy and epoxy/polyurethane piezoelectric composites.     

High-damping polyurethane/hollow glass microspheres sound insulation materials: Preparation and characterization

The high-damping property of polyurethane elastomers and the low density of the hollow glass microspheres (HGM) were used to prepare the sound insulation materials in the present work. The transmission loss (TL) was measured to evaluate the HGM content on the sound insulation properties. The experimental results showed that the addition of HGM improved the hardness and compression modulus of the HGM-filled polyurethane composites, and the loss factor (tan δ) of polyurethane composites were greater than 0.9. The average transmission loss (ATL, from 63 to 6300 Hz) reached 37.32 dB when the content of HGM was 10 wt%. The ATL of the HGM-filled polyurethane composites with 15 wt% HGM in the damping control region and the mass control region were 31.94 and 46.78 dB, respectively. The synergistic effect of the microphase separation, the interfacial effect and the rigidity of polyurethane composites resulted in the improvement on sound insulation property. The polyurethane composite has a great potential application for the field of sound insulation materials.     

热压法制备压电陶瓷／聚合物复合材料及性能研究

采用热压法分别制备了PZT／PVDF,PT／PVDF O-3型压电复合材料,所得材料具有较高的压电常数和良好的可柔性加工性能。并分析了无机压电陶瓷种类、含量对复合材料介电性能和压电性能的影响。     

Piezoelectric response of porous ceramic and composite materials based on Pb(Zr,Ti)O3: experiment and modelling

Abstract

The present paper presents experimental and theoretical studies of the effective piezoelectric properties of porous Pb(Zr,Ti)O₃ based ceramics and composites. The experimental dependence of piezoelectric coefficients and dielectric permittivity on relative density is determined for porous materials containing different piezopassive components. The piezoelectric response of these materials in a wide range of volume concentrations of the piezopassive components are analysed in the framework of a model of a modified laminated composite with 2–2 and 1–3 connectivity elements. The role of these elements in forming different concentration dependences of the effective parameters of the porous piezoceramic and piezocomposite materials is discussed.     

改性高岭土/水性聚氨酯复合材料的制备与表征

采用钛酸酯偶联剂干法改性高岭土,配成母液,用此母液乳化中和后的聚氨酯预聚体,制得改性高岭土/水性聚氨酯复合材料(WPUM)。研究了复合材料的乳液粒径、胶膜力学性能、结晶性和热稳定性等性能。结果表明:复合材料乳液粒径随着改性高岭土质量分数的增加,先增加后减小;改性高岭土的加入可以明显提高水性聚氨酯胶膜的力学性能,当改性高岭土质量分数为1.6%时,复合材料的断裂伸长率与纯聚氨酯胶膜相比提高了13%;X射线衍射法(XRD)分析结果显示,改性高岭土促进了聚氨酯的微相分离;热重分析法(TG)、差示热重法(DTG)分析结果表明,水性聚氨酯复合材料胶膜热分解的起始温度无变化,硬段最高热失重温度略有降低。     

光固化超支化聚氨酯的制备及其阻尼性能研究

以甲苯-2,4-二异氰酸酯(TDI)、二乙醇胺(DEOA)和丙烯酸羟乙酯(HEA)为原料,合成了光固化超支化聚氨酯(UV-HPU)。结果表明:随着HEA含量的增加,树脂的热稳定性能、柔韧性和阻尼性能均有所提高;当w(HEA)=40%时,树脂的阻尼性能最好,tanδ峰值达到最大值(0.76),其力学性能接近甚至超过国内外同类产品。     

CNT loaded PVDF-KNN nanocomposite films with enhanced piezoelectric properties

The emerging smart PVDF-based composites can compensate for the intrinsic property deficiencies in either of their components. The properties of the composite are determined by the properties of the constituents and its fabrication method. In this research, a lead-free piezoelectric ceramic, potassium sodium niobate (KNN), was used as the primary reinforcement, and MWCNTs were added to improve the electrical properties. Solution casting was used to prepare PVDF-KNN-CNT composite films. After phase and structure identification of composites using SEM, XRD, FTIR, and TGA methods, the dielectric, piezoelectric and ferroelectric properties of the products were investigated. The obtained results indicated a strong dependency of dielectric, piezoelectric, and ferroelectric properties of composites on KNN content. Samples with the highest KNN content rendered ε_r, d₃₃ and g₃₃ values of 156, 28 pC/N, and 20.32 mV m/N, respectively. Introducing a small amount of conductive CNT to primary PVDF-KNN composites can drastically affect the electrical properties by severely interfering in the charge distribution within the sample. While the dielectric constant was enhanced by increasing CNT content, both piezoelectric and ferroelectric properties showed their best behavior at a critical CNT loading. Beyond this limit, a percolation path formed, which is responsible for power consumption. At the optimum CNT amount, d₃₃ and g₃₃ reached 50 pC/N and 31.93 mV m/N, respectively. The presence of conducting CNTs gave rise to the formation of more round polarization curves with higher remnant polarization. The present findings give a prospective understanding of smart piezoelectric polymer-based composites that can be used as sensors and energy harvesters.     

铁掺杂钛酸铋钠钾陶瓷的制备及表征

采用传统固相法制备了无铅压电陶瓷Bi0.5(Na0.825K0.175)0.5TiO3+xFe2O3(x为质量分数,0、0.1%、0.3%、0.5%、0.7%、1.0%、1.5%)(简写BNKTF-x),利用X射线衍射(XRD),和扫描电子显微镜(SEM)等分析表征了该体系陶瓷的结构、介电与压电性能。XRD测试表明,在1 180℃、2 h的烧结条件下,当铁的质量分数小于1.0%时,陶瓷呈现单一相的钙钛矿结构。所有陶瓷晶粒大多呈四方晶形,晶界明显。增加铁的含量有利于晶粒生长。此外,铁的加入也使陶瓷样品气孔率降低,当铁的质量分数在0.3%左右时陶瓷的致密性最好。BNKTF-0.1%体系陶瓷具有较好的电学性能:d33=145 pC/N,kp=0.28,εr=869,tanδ=0.032,Qm=106。