HIGH PERFORMANCE POLYMERS
·
2018
·
IF 1.047
Jingting Wang,Yanfeng Wei,Xuesong Li,Jianxin Mu
A series of novel poly(aryl ether sulfone)s (PESs) with polyhedral oligomeric silsesquioxane (POSS) and biphenyl group in the main chain were synthesized from 4,4′-biphenol, biphenol POSS and 4,4′-bis[(4-chlorophenyl)sulfonyl]-1,1′-biphenyl via a nucleophilic aromatic substitution polycondensation. The structures of the polymers were characterized by infrared, nuclear magnetic resonance, and wide-angle X-ray diffraction spectroscopy. The incorporation of POSS and biphenyl group into PES matrix at various molar percentages of POSS resulted in a dramatic decrease of dielectric constant as well as a significant increase of hydrophobicity. As the content of POSS increased, the dielectric constant decreased from 2.54 to 1.82, while the contact angle can be increased to 122.6°. The thermal properties, crystallinity, solvent resistance, and surface topography were also studied in this article.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
高影响因子
Materials
·
2018
·Vol. 11
·期 9
·1756
·
IF 2.467
Mi Zhang,Yu Gao,Yixing Zhan,Xiaoqing Ding,Ming Wang,Xinlong Wang
Degradable, flame retardant, and flexible nanocomposite films with low dielectric constant were prepared with poly (lactic acid) (PLA), nano ZIF-8@GO, and degradable flame-retardant resorcinol di(phenyl phosphate) (RDP). The SEM results of the fractured surfaces indicated that ZIF-8@GO and RDP were dispersed uniformly in the PLA matrix. The prepared films had good mechanical properties and the tensile strength of the film with 1.5 wt% of ZIF-8@GO was increased to 48.2 MPa, compared with 38.5 MPa of pure PLA. Meanwhile, the nanocomposite films were flexible due to the toughing effect of RDP. Moreover, above 27.0% of limited oxygen index (LOI) and a VTM-0 rating were achieved for the nanocomposite films. The effects of nano ZIF-8@GO hybrids and RDP on the dielectric properties were investigated, and the results showed that ZIF-8@GO and RDP were beneficial in reducing the dielectric constant and dielectric loss of the nanocomposites.
研究领域:
材料科学
·
电子工程
✓ 已验证
DOI
高影响因子
Crystals
·
2021
·Vol. 11
·期 11
·1383
·
IF 2.589
Panpan Zhang,Lize Zhang,Ke Zhang,Jiupeng Zhao,Yao Li
Due to the high value of its dielectric constant, polyimide does not meet the requirements of the development of integrated circuits and high-frequency printed circuits. The development of novel low dielectric constant polyimide materials for the preparation of flexible copper clad laminates is of theoretical and practical significance in the application of polyimide for 5G communications. In this work, different fluorinated graphene/polyamic acids (FG/PAA) were used as the precursor, and the porous polyimide film was successfully prepared by phase inversion. The dielectric constant of the porous polyimide film is relatively low, being less than 1.7. When the content of fluorinated graphene is 0.5 wt%, the overall dielectric performance of the porous film is the best, with a dielectric constant of 1.56 (10 kHz) and a characteristic breakdown field strength of 56.39 kV/mm. In addition, the mechanical properties of the film are relatively poor, with tensile strengths of 13.87 MPa (0.2 wt%), 13.61 MPa (0.5 wt%), and 6.25 MPa (1.0 wt%), respectively. Therefore, further improving the breakdown resistance and mechanical properties of the porous film is essential for the application of porous ultra-low dielectric polyimide materials.Keywords:polyimide;phase inversion;dielectric constant;porous films
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POLYMER SCIENCE
·
2025
·
IF 3.6
Panpan Zhang,Ke Zhang,Ting Du,Shuliang Dou,Jiupeng Zhao,Yao Li
The high dielectric constant inherent to traditional polyimides (PIs) limits their ability to meet the demands of high-frequency circuit boards. The challenge of reducing this dielectric constant, while simultaneously preserving or enhancing the material's overall performance, is of critical theoretical and practical significance for advancing the use of PIs in the 5G communication sector. In this study, fluorinated graphene/polyimide (FG/PI) was employed as a reinforcing layer to fabricate a double-layer structure that enhances the mechanical and breakdown properties of low-dielectric PIs. PI porous composite films were developed using a layer-by-layer coating method, and their dielectric, mechanical, and thermal properties were investigated. The resulting double-layer PI films exhibited low dielectric constants and robust comprehensive performance. Specifically, the dielectric constants of the three films, PI-1, PI-2, and PI-3, were 2.01, 1.90, and 1.70, respectively, with corresponding tensile strengths of 42.69 MPa, 37.54 MPa, and 24.41 MPa, and breakdown strengths of 180.75 kV mm −1 , 138.70 kV mm −1 , and 89.77 kV mm −1 . These results underscore the importance of multi-layer structural designs in enhancing the breakdown resistance and mechanical properties of porous films, which are critical for the practical application of low-dielectric porous PI materials. Graphical The preparation process and properties of double-layer polyimide films.
研究领域:
材料科学
·
电气工程
·
高分子复合材料
·
纳米技术
·
通信技术
✓ 已验证
产品关联
DOI
高影响因子
Advanced Industrial and Engineering Polymer Research
·
2020
·
IF 0
Lishuai Zong,Chuang Li,Yuan Zu,Jinyan Wang,Xigao Jian
Modern microelectronics devices urgently request low dielectric constant materials with commendable mechanical properties. Novel fluorinated poly(aryl ether)s (FPPEs) were prepared by traditional polycondensation of 4-(4-Hydroxylphenyl)(2H)-phthalazin-1-one (DHPZ), Bisphenol AF (BAF) and Decafluorobiphenyl (DFB) to study bulky phthalazinone effects on mechanical and dielectric behavior of polymers. After the introduction of phthalazinone moieties, FPPEs showed excellent solubility to readily solve in many organic solvents like NMP, DMAc, CHCl 3 , and THF. Simultaneously, they exhibited relatively high glass transition temperatures ( T g s) from 180 °C to 294 °C, increasing with the content of phthalazinone groups. The FPPEs still possessed excellent thermal stability with decomposition temperature up to 514 °C and char yield at 800 °C as high as 56% under nitrogen atmosphere. FPPE films showed good mechanical strength with tensile stress higher than 68 MPa and modulus surpassing 10.8 MPa, also increasing with phthalazinone concentration. The dielectric property of FPPEs was investigated with impedance analyzer. FPPE8020 and FPPE 6040 showed dielectric constant from 3.10 to 3.30 and dielectric loss of 0.005–0.008 under a large frequency range of 0.02–60 GHz. The phthalazinone moieties mainly contributed to the decrease of dielectric constant. The results evidently suggest FPPEs as commendable candidate for those high-tech electronic applications.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
MATERIALS SCIENCE FORUM
·
2020
·
IF 0
Zhi Wei He,Hong Xiao Lin,Chun Yan Li,Ashok M. Mahajan,Swati A. Gupta,Mei Zhou
Effect of various silicon sources, such as TEOS, MTES mixed with TEOS and 1,3,5-tris(triethoxymethyl) on SiO2 films was investigated. The synthesized solutions were used as silicon sources to prepare silica-like backbone films. The investigation showed that all precursors can able to produce the flat and uniform films. An FTIR spectrum confirmed the formation of SiO2 in film matrix. The results indicated that the internal microstructure of each film is different. The incorporation of less polar bonds such as F and C was carried out using various Si sources, while the introduction of these sources confirmed through FTIR spectra. Optical properties of the films were carried out by using ellipsometric porosometry (EP) measurement. The leakage current density for the films prepared by using TEOS, MTES and 135TTEB was observed to be 2.8 × 10-7 A/cm2, 2.9 × 10-8 A / cm2, and 4.1 × 10-6 A / cm2, respectively, at 1 MV/cm electric field strength by the IV curves obtained by semiconductor characterization after fabricating MIS devices. The calculated dielectric constants from RI of the deposited SiO2 films were 2.0, 1.9 and 2.5 respectively. When the microstructure of the precursor solution changed, the introduction of atomic morphology or terminal inerted group ratio changed the internal bridging mode of SiO2, and thereby significantly reduced the dielectric constant and improved insulation.
研究领域:
材料科学
·
电子工程
✓ 已验证
DOI
POLYMER
·
2024
·
IF 4.1
Siqi Zhang,Shu Wu,Qi Wang,Mengxiang Guan,Bowen Yang,Guirong Peng,Xiaojia Zhao
P(VDF-HFP) is widely used in transistors, electret and artificial skin due to its excellent dielectric properties . In order to dramatically improve its dielectric constant, conductive fillers are used for doping, but the compatibility is not optimistic between the fillers and the PVDF . In this paper, PEDOT:PSS/P(VDF-HFP) all-organic films with interpenetrating network structure were prepared by the addition of H 2 O. The dielectric constant of the film with 0.5 wt % PEDOT:PSS reached up to 323 and the tanδ was only 0.48 (1 k Hz, 18 °C). The addition of the H 2 O made the small amount of PEDOT:PSS evenly distribute in the P(VDF-HFP), as a result, the percolation threshold decreased. Besides, molecular chains of PEDOT:PSS were overlapped to form a uniform network. This paper provided a novel preparation method for a uniform film with two kinds of matters with different compatibility.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2021
·
IF 5.302
Bing Liu,Ke Sha,Meng Fei Zhou,Kai Xin Song,Yu Hui Huang,Cheng Chao Hu
Two novel low- ε r gallates MGa 2 O 4 (M = Ca, Sr) have been synthesized via a standard solid-state reaction method. According to the X-ray diffraction results, CaGa 2 O 4 crystallizes in space group Pna2 1 with an orthorhombic symmetry, while SrGa 2 O 4 belongs to the monoclinic P2 1 / c system. Both ceramics show ever-improving microstructures with the increasing sintering temperature . The optimal microwave dielectric properties ( ε r = 9.2, Qf = 66,000 GHz, τ f =–85 ppm/°C for SrGa 2 O 4 and ε r = 10.6, Qf = 15,400 GHz, τ f =–58 ppm/°C for CaGa 2 O 4 ) are obtained when sintered at 1275 °C. A patch antenna is fabricated using SrGa 2 O 4 ceramics as the substrate, which realizes a return loss of –19.94 dB and total efficiency of –1.38 dB (72.8 % in power ratio) at 4.84 GHz. The exceptional performances indicate that SrGa 2 O 4 ceramics are promising candidates for antenna applications at the Sub-6 GHz band.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
Materials Today Physics
·
2021
·
IF 9.298
Feichong Yao,Wenhao Xie,Ming Yang,Hang Zhang,Hongbo Gu,Ai Du,Nithesh Naik,David P. Young,Jing Lin,Zhanhu Guo
With the purpose of ameliorating the electrical property, permittivity and magnetoresistance of polyaniline (PANI) nanofibers , three types of phenylenediamine (PDA), including o -PDA, m -PDA, and p -PDA, and different contents of PDA have been incorporated into the PANI polymer backbone by the interfacial copolymerization of aniline with PDA. The results demonstrate that different types and contents of PDAs could disclose the distinct effects on the chemical structures , crystalline structures, and morphologies for copolymers of aniline with PDA affirmed by Fourier transform infrared (FTIR) spectroscopy, solid-state 13 C nuclear magnetic resonance ( 13 C NMR), X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscopy (TEM). The molecular weight of all copolymers is reduced by several orders of magnitude relative to pure PANI nanofibers confirmed by gel permeation chromatography (GPC). The resistivity variations for the copolymers of aniline with different types of PDAs are well explained from the point view of their molecular structures based on the first-principle simulations (i.e. intrachain electrical conductivity) and degree of crystallinity gained from XRD (i.e. interchain electrical conductivity). A tunable room-temperature magnetoresistance (MR) and a controllable negative permittivity are discovered in the copolymers of aniline with different types and contents of PDAs. This work provides a new insight for the manipulation of electrical transport for PANI nanofibers and helps seek the new applications of conductive polymer .
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2018
·
IF 3.779
Chunli Diao,Hanxing Liu,Haiwu Zheng,Zhonghua Yao,Javed Iqbal,Minghe Cao,Hua Hao
Electrostatic dielectric energy storage capacitors have attracted much attention recently for their fast charging-discharging speed and high power density. Trilayered Ba 0.4 Sr 0.6 TiO 3 /BaTiO 3 /Ba 0.4 Sr 0.6 TiO 3 (BST/BT/BST) thin films were prepared by spin-coating technique. The sandwich-structured thin films showed high dielectric constant (ε r = 952) and low dielectric loss (tanδ = 0.034) at room temperature (10 kHz). Moreover, the dielectric constant of the thin films demonstrated good frequency stability within the measured frequency range and broad capacitance variation (20 °C–160 °C, ΔC/C 25°C <±10%). The electric-field dependence of dielectric response was investigated and the dielectric tunability was 13.3% at 100 kV/cm. Compared with pure BT thin films, the heterostructure exhibited enhanced electric breakdown strength and energy storage density. The recoverable energy storage density and efficiency of BST/BT/BST thin films were 14.69 J/cm 3 and 33.9% at 1.44 MV/cm, respectively. The results indicated that BST/BT/BST heterostructure films would be an alternative way to improve the energy storage density of dielectrics for applications.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
Polymer Chemistry
·
2021
·Vol. 12
·期 16
·2481-2489
·
IF 5.582
Tianwen Zhu,Qiaoxi Yu,Weiwen Zheng,Runxin Bei,Wenhui Wang,Minming Wu,Siwei Liu,Zhenguo Chi,Yi Zhang,Jiarui Xu
The precision regulation of the dielectric polarization and dielectric loss of polymer materials, developing intrinsic high-performance polymers with high dielectric constant, low dielectric loss and excellent temperature resistance is very challenging. In this work, a facile molecular design strategy was developed by directly introducing two ortho-position aromatic nitrile groups into the rigid polyimide backbone. Compared with similar polyimides without nitrile groups (0CN-PIs), the polarizability and dielectric constant of the designed polyimide (2CN-PIs) can be greatly increased. Meanwhile, the polarization motions of the nitrile groups can be limited at room temperature, which is beneficial to lowering the dielectric loss. Among the designed polyimides, 2CN-BTDA shows a high k value of 4.80, low dielectric loss of 1.57 × 10−3 at 1 kHz (25 °C), and breakdown strength of 219.4 kV mm−1 with high maximum discharge energy density of 1.023 J cm−3. Moreover, its Tg value is as high as 325 °C, much higher than that of most traditional dielectric polymers. The essence of designing high-k–low-loss intrinsic polymers was revealed by reconsidering the Clausius–Mossotti equation, where the total polarizability should be maximized while the chain stacking should be as tight as possible; that is, a rigid polymer backbone, small sized polar groups (like nitrile groups), and a spatial position in favor of orientation polarization are preferred. The results are helpful to promote the research progress of dielectric polarization and of great significance to the development of high-performance high-k–low-loss dielectric materials for potential applications in modern electronic information and microelectronic industry.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
MACROMOLECULAR RAPID COMMUNICATIONS
·
2023
·Vol. 44
·期 10
·2200971
·
IF 4.6
Jie Mao,Jing Li,Wang Lin,Faliang Luo
This work describes an easy and effective process for preparing a homogeneous polybutadiene (PB) dielectric elastomer with improved actuated strain by utilizing a photochemical thiol-ene click reaction. The carboxyl groups and various ester groups are used for grafting on the PB. Since the length of the alkyl chains of the ester groups will significantly influence the polarities of the carbonyl groups and hydrogen bonding effect, the influence of polarity and hydrogen bonding effect on the dielectric properties and mechanical properties of the modified polybutadienes is carefully discussed. Very interestingly, it is found that the increment of dielectric constant of PB modified by carboxyl groups is the lowest one compared to other modified PBs with the ester groups. Meanwhile, the modified PBs with the ester groups could achieve pretty low dielectric loss factor, and finally, a high dielectric constant (3.6), low dielectric loss factor (0.0005), and large actuated strain (≈25%) of the modified polybutadienes could be achieved by the modified PBs with butyl acrylate groups. This work provides a simple and effective method for the designing and synthesizing of a homogeneous high electromechanical performance dielectric elastomer with high dielectric constant and low dielectric loss.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）