聚醚酰亚胺/改性钛酸钡复合材料制备及介电储能性能

采用Stober法对高介电常数陶瓷填料钛酸钡(BT)进行改性,得到二氧化硅(SiO2)包覆BT(BT@SiO2)填料,并采用溶液浇铸法制备具有高介电储能性能的聚醚酰亚胺(PEI)/BT@SiO2复合材料薄膜,研究了复合材料薄膜的表面结构、结晶行为、介电性能、储能性能等.X射线衍射(XRD)及透射电子显微镜结果表明,Si...     

新型含氟聚醚酰亚胺的合成与表征

利用对苯二酚、2-氯-5-硝基三氟甲苯合成得到1,4-双(2-三氟甲基-4-硝基苯氧基)苯,再在钯/炭、水合肼和有机溶剂的作用下,合成得到了1,4-双(2-三氟甲基-4-氨基苯氧基)苯,并对其性能进行了表征,包括其本身的熔点、红外吸收特征等。合成得到的1,4-双(2-三氟甲基-4-氨基苯氧基)苯与4,4'-二氨基二苯醚、2,2-双[4-(3,4-二羧基苯氧基)苯基]丙烷二酐反应,制得了含氟聚醚酰亚胺,并对其性能进行了表征。     

柔性PMIA复合电介质的制备及其储能特性

为了抑制由于钛酸钡(BT)纳米粒子和聚间苯二甲酰间苯二胺(PMIA)介电常数差异引起的PMIA复合电介质内部局部电场畸变,分别将TiO₂和聚多巴胺(PDA)包裹在BT纳米粒子表面形成双核壳结构PDA@TiO₂@BT复合粒子(PTBP),随后将PTBP与PMIA浆料复合制备了PTBP/PMIA复合膜。采用FTIR、XRD、SEM对样品进行了表征,测试了PTBP/PMIA复合膜的介电性能、击穿强度及储能特性。结果表明,随着PTBP含量(以PMIA固体质量计,下同)的增加,PTBP/PMIA复合膜的介电常数明显提升;当PTBP含量为10%时,PTBP/PMIA复合膜在1×10³ Hz时的介电常数比PMIA基体提高了57.1%,在高温环境中(>150℃),其介电性能保持稳定。此外,PTBP还明显改善了PTBP/PMIA复合膜的储能特性;当PTBP含量为10%时,PTBP/PMIA复合膜在室温、电场强度为250 MV/m时的储能密度和放电能量密度分别为1.91和1.23 J/cm³,比PMIA基体分别提...     

新型含嘧啶核的超支化聚酰亚胺的制备与表征

采用3,3′,4,4′-二苯甲酮四酸二酐(BTDA)为A2型单体,2,4,6-三氨基嘧啶(TAP)为B′B2型单体,通过控制BTDA和TAP的比例制备了一系列含有嘧啶核的超支化聚酰亚胺(HBPI)。采用傅立叶变换红外光谱、核磁共振、热失重分析和溶解性测试对合成的HBPI进行了结构表征和性能研究。结果表明,合成的新型含嘧啶核的HBPI在强极性非质子溶剂中具有良好的溶解性;新型HBPI的耐热性能比普通聚酰亚胺有所降低,但仍具有较为优异的耐热性能。     

超临界流体法制备聚醚酰亚胺泡沫的研究

研究了超临界流体发泡聚醚酰亚胺(PEI)的制备方法,采用复合超临界流体发泡剂解决了PEI发泡倍率不高的问题。结果表明:制备的发泡粒子表观密度15~20 kg/m~3,闭孔率100%,泡孔直径小于100μm,发泡倍率高达50~60。采用物理发泡法,加工过程没有改变原树脂的化学结构和性能,可以最大程度保持聚PEI树脂的特性。     

新型阻燃聚醚多元醇的合成研究

以 3 (2 ,4 ,6 三溴苯氧基 )环氧丙烷为阻燃单体 ,N ,N 二 (2 羟基乙基 ) 2 ,4 ,6 三溴苯胺为起始剂 ,合成了具有阻燃特性的聚醚多元醇。着重考察了反应物料比、投料方式、反应时间等因素对阻燃聚醚多元醇物理性质及收率的影响。应用试验结果表明 :适合制造软泡材料的阻燃聚醚多元醇原料配方是 :起始剂 /环氧丙烷/ 3 (2 ,4 ,6 三溴苯氧基 )环氧丙烷物质的量比为 0 18/ 3/ 1。当阻燃聚醚多元醇质量分数为 19%的国产 2 5 # 软质聚氨酯泡沫 ,氧指数达 2 7 1,其它物理特性也满足了GB/T 2 4 0 6 - 1993的要求。     

立构规整性偶氮苯聚醚的制备及储能性质

太阳能热燃料可以实现在一个封闭的循环系统中,通过分子构象的转换捕获和储存太阳能,并按需以热的形式释放能量。本文通过外消旋偶氮苯基环氧烷烃对映选择性均聚,合成出一系列具有主链手性的立构规整性偶氮苯聚醚,深入研究了偶氮苯聚醚的热性质、光异构化和作为新一代太阳能热燃料的储能性质。结果表明,等规反式偶氮苯聚醚均为半结晶材料,熔点为230~259 ℃,结晶温度为197~219 ℃；聚醚中的偶氮苯基团在光照下可实现高效可逆的顺反异构化转变。由于等规聚醚自结晶的特点,其储能密度较无定形聚醚有明显提高,最高可达193.7 J/g,说明结晶性对偶氮苯聚合物的储能密度中起着重要作用。本文利用立构规整性聚合物的自结晶特点提高偶氮苯类聚合物的储能密度,为聚合物储能材料的研究提供了新思路。     

新型聚醚基三硅氧烷表面活性剂的制备及表面活性

以巯丙基三硅氧烷与聚乙二醇烯丙基甲基醚经thiol-ene反应合成了新型聚醚基三硅氧烷表面活性剂,并对其结构进行了FT-IR和~1H NMR表征,通过表面张力的测定考察了其表面活性。结果表明,该法可以高效合成高纯度的聚醚基三硅氧烷表面活性剂,该表面活性剂能将水的表面张力降低至21～23 mN/m,具有优良的表面活性。     

新型高活性聚醚多元醇的制备及应用

详细介绍了用三(五氟苯基)硼烷为代表的新型Lewis酸催化剂制备高活性聚醚多元醇的工艺,并介绍了该高活性聚醚多元醇在聚氨酯(PU)泡沫及弹性体中的应用情况,指出用该新型聚醚多元醇制备的PU树脂具有优异的固化特性、力学性能、耐水性和湿热稳定性。     

萘酰亚胺树枝状聚（胺-酯）荧光材料的合成及性能

以乙二胺(EDA)、三羟甲基丙烷三丙烯酸酯(TMPTA)和1,8-萘二甲酸酐为原料,合成了萘酰亚胺树枝状聚(胺-酯)(PAE-1,8-NL),产率为32.79%。用IR和1HNMR表征了它的结构。通过紫外-可见吸收光谱、荧光光谱等手段对PAE-1,8-NL及加入稀土金属离子(La3+、Nd3+、Dy3+、Gd3+、Eu3+)或质子的各种溶液的光物理性能进行研究。结果表明,PAE-1,8-NL在氯仿-乙醇(体积比1∶1)稀溶液中在激发波长为335 nm激发下产生两处荧光峰370 nm和386 nm,分别归属为萘单体荧光峰和分子内萘基-萘基激基缔合物荧光峰;稀土金属离子或质子与PAE-1,8-NL内部的胺络合后,对萘单体荧光峰影响不大,而对激基缔合物荧光强度产生规律性的变化。PAE-1,8-NL溶液的荧光强度随稀土金属离子浓度的增大先增强后减弱;随H+浓度的增大而增强;随稀土金属离子和H+浓度的增大先增强后减弱。     

Energy storage density and efficiency of polyetherimide nanocomposites diminished by the temperature dependent charge hopping

The utilization of renewable energies requires extensive use of energy storage equipment such as dielectric capacitor. Polyetherimide nanocomposites (PEI PNCs) have high energy storage performance, and become the next generation advanced dielectric s However, the quantitative relation between the charge transport and energy storage of PEI PNCs is not very clear, restricting further improvement of their performance. Considering the charge injection from electrodes and the charge hopping transport inside the dielectric, the energy storage and release model of capacitors was established. Firstly, the conductivities of PEI PNCs were simulated, and the charge transport parameters were determined by comparing with the experiments. Then, the electric displacement-electric field (D-E) loops of PEI PNCs were simulated, and the discharged energy density and energy efficiency were calculated from them. The simulation results are consistent with the experiments, and the quantitative relationship between charge injection and transport parameters and energy storage performance is established. In addition, it is found that the energy storage density and efficiency are diminished by the increase of hopping distance at high temperatures. Increasing the hopping barrier, reducing the hopping distance and its temperature dependence through nano-doping can significantly improve the energy storage performance under high temperatures and high electric fields.     

Preparation and characterization of sulfonated polyetherimide/polyetherimide blend membranes

Polyetherimide (PEI) was sulfonated by chlorosulfonic acid (CSA) in 1,2‐dichloroethane for the first time. With the increase of the CSA/PEI repeat unit ratio and/or reaction time, the ion‐exchange capacity (IEC) of the sulfonated polyetherimide (SPEI) increased accordingly. Water‐uptake testing and contact‐angle measurement showed that the hydrophilicity of the SPEI increases with the increase of the IEC. Membranes were fabricated from SPEI/PEI blends with different ratios. The morphologies of the blend membranes were examined by scanning electron microscopy, which showed that the membrane pore size is larger when SPEI with higher IEC was used. With the increase of SPEI ratio in the blend membranes, the membrane pore size also increased. The contact‐angle data of the membranes showed that the hydrophilicity of the blend membrane was elevated because of the sulfonate group on the SPEI molecular backbone. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 1709–1715, 2004     

Enhanced electrocaloric response and energy storage performance of Li-substituted BaTiO3 ceramics

Recently, ferroelectric and antiferroelectric ceramic materials have gained a lot of interest for the development of environment-friendly highly-efficient electrocaloric refrigeration and energy-storage devices. In this work, lead-free Ba_1−xLi_xTiO₃ ceramics with x = 0, 0.01, 0.02, 0.03, 0.04, and 0.05 were synthesized by the conventional solid-state reaction method, and the effect of Li doping on dielectric, leakage current, ferroelectric, electrocaloric, and energy storage properties of BaTiO₃ ceramics was systematically investigated. The XRD and Raman studies confirmed that the structure of Ba_1−xLi_xTiO₃ remains tetragonal as for BaTiO₃. The Li substitution shifted the phase transition (T_C) of BaTiO₃ slightly towards the lower temperature side. Significant drop in leakage current was observed with an addition of Li content. The maximum values of the electrocaloric effect (ΔT), electrocaloric responsivity, and coefficient of performance were found to be 1.44 K, 0.24 × 10⁻⁶ K m/V, and 5.75, respectively, for x = 0.04 at an applied field of 60 kV/cm near the Curie temperature. The maximal value of energy storage density was found to be 0.42 J/cm³ with an energy storage efficiency of 60% for x = 0.05. Our results suggested that lead-free Ba_1−xLi_xTiO₃ ceramic material is a promising candidate for potential applications in solid-state refrigeration technology and high-efficiency energy storage devices.     

Preparation and characterization of a novel injectable in situ cross-linked hydrogel

A novel injectable in situ cross-linked hydrogel was prepared from α,β-poly(N-hydroxyethyl)-dl-aspartamide (PHEA), which had excellent biocompatibility and biodegradability. PHEA was modified by acryloyl chloride (AC) via the reaction between hydroxyl groups and acryl groups to introduce reactable double bonds into the chain. Two macromers with different degrees of derivatization were prepared. Through NMR and FT-IR characterizations, the structures of the polymers were proposed. Hydrogels were prepared by covalent cross-linking between double bonds with a transition from liquid to gel at body temperature. The effect factors on gelation time, swelling ratio and gel content were investigated in detail. It was found that the grafting ratios of AC, concentrations of macromer and initiator had great influence on the gelation time. And it could be adjusted to meet the requirements of an injectable material.     

压气储能系统中储气装置的性能分析与改进

压缩空气储能系统是一种大规模的能量存储技术,在可再生能源利用以及调峰领域发挥重要作用。储气室作为系统中主要的储能设备,其特性对系统运行有重要影响。为了研究储气室热力特性对AA-CAES系统性能的影响,设计能够提高系统性能的新型储气装置,建立实际、绝热、恒温3种储气室模型,并结合其他部件模型,对系统进行联合求解。分析求解结果发现,储气室绝热模型具有最高的储能效率,可以达到68.97%,恒温模型的储能密度最高,为2.4706 kW·h/m³,实际模型的储能效率和储能密度都较低;恒温模型下系统的性能受到环境温度的影响,提高环境温度可以使储能效率上升,但会导致储能密度下降;改进的储气装置能够结合绝热模型与恒温模型的优点,使系统性能获得改善。     

Review of recent advances of polymer based dielectrics for high-energy storage in electronic power devices from the perspective of target applications

Polymer-based dielectric capacitors are widely-used energy storage devices.However,although the functions of dielectrics in applications like high-voltage direct current transmission projects,distributed energy systems,high-power pulse systems and new energy electric vehicles are similar,their requirements can be quite different.Low electric loss is a critical prerequisite for capacitors for electric grids,while high-temperature stability is an essential pre-requirement for those in electric vehicles.This paper reviews recent advances in this area,and categorizes dielectrics in terms of their foremost properties related to their target applications.Requirements for polymer-based dielectrics in various power electronic equipment are emphasized,including high energy storage density,low dissipation,high working temperature and fast-response time.This paper considers innovations including chemical structure modification,composite fabrication and structure re-design,and the enhancements to material performances achieved.The advantages and limitations of these methods are also discussed.     

LiTaO3 assisted giant strain and thermally stable energy storage response for renewable energy storage applications

Piezoceramics with composition (1–z) [Bi_0.5(Na_0.84K_0.16)_0.5TiO₃]_0.96–0.04SrTiO₃–zLiTaO₃ (z = 0.00–0.030) were formulated by ordinary firing process following by rapid quenching treatment. Effect of LiTaO₃ on the structural, electrical and energy-storage properties were analyzed. For the composition with molar ratio 0.025, room temperature large-field piezoelectric coefficient (S_max/E_max = d₃₃*) of 885 pm/V at 3.6 kV/mm was recorded. Furthermore, for compositions z = 0.025 and 0.030, broad temperature stable dielectric constants and low losses from ~135 to 350 °C with a small variation of ± 15% was observed. Additionally, the energy density for z = 0.025 was ~0.60 J/cm³ in the broader temperature range of 75–125 °C, along with the energy-storage efficiency of greater than 70%. These observations suggest that the studied piezo-material compositions are promising for the ceramic actuators and capacitor applications.     

Improved energy storage density and energy efficiency of Samarium modified PMNT electroceramic

We report the improved energy storage density and efficiency after 2.5% of Samarium substitution in ferroelectric Pb[(Mg_1/3Nb_2/3)_0.80Ti_0.20]O₃ (PMNT) electroceramic. The microstructure and surface morphology were analyzed and correlated with various functional properties. The energy storage density, leakage current density, ferroelectric and dielectric properties were investigated thoroughly, indicating that Samarium's substitution significantly modified the microstructure, the dielectric strength, breakdown electric field, and turned ferroelectric PMNT to relaxor ferroelectrics. Due to the relaxor nature, the gap between remanent polarization and maximum polarization increases with the substitution of Samarium in PMNT matrix, which further increases the recoverable energy storage density and energy efficiency. A nearly 100% increase in recoverable energy density and efficiency was obtained at an electric field strength of 35 kV/cm at room temperature (～296 K). The electroceramic shows maximum energy density near the ferroelectric phase transition temperature (325 K–345 K) region and provides a moderate energy storage density for possible applications in power microelectronics.     

Optimization of high temperature energy storage properties of PEI-based composite dielectric based on rapid in-situ growth of inorganic functional layer

The serious deterioration of the energy density of polymer energy storage dielectrics in high temperature environment is the main reason to curb the in-depth application of dielectric film capacitors in the field of modern electrical and electronic engineering. Here, aiming at the problem of low dielectric constant of polymer dielectric, a simple, low-cost method is proposed to grow inorganic polar functional layer on surface of polymer film in situ, which effectively improves the polarization characteristics of polymer dielectric at high temperature. The in situ growth of Ti(OH)₄ inorganic polar functional layer on surface of polyetherimide (PEI) film noteworthy to improve the energy storage performance of dielectric film. The energy storage density of 4.59 J/cm² is obtained at 150°C and 600 MV/m, which is 1.18 times that of PEI film under the same condition. The significant enhancement of high temperature energy storage density can be attributed to introduction of functional layer, which effectively improves the dielectric properties and polarization intensity of dielectric film. Furthermore, the facile preparation method provided in this paper can be applied to various thin films under the premise of controllable cost, which is of great significance to improve the high temperature energy storage characteristics of polymer dielectric.