Quartz fiber cloth-reinforced semi-aromatic thermosetting polyimide composite with high-frequency low dielectric constant

2019 ◽  
Vol 32 (1) ◽  
pp. 91-102 ◽  
Author(s):  
Zhen-he Wang ◽  
Hai-xia Yang ◽  
Shi-yong Yang

We report a series of semi-aromatic thermosetting polyimide (PI) resins that can be used as matrix for copper-clad laminates for high-frequency applications. The poly(amic ester) (PAE) resins derived from the diester of 1,2,4,5-cyclohexanetetracarboxylic dianhydride, aromatic diamines (the mixture of 2,2′-dimethylbenzidine and 2,2′-bis[4-(4-aminophenoxy) phenyl] propane), and the monoester of nadic anhydride were synthesized by Polymerization of Monomer Reactants (PMR) method. The structure conversion of PAE resins at different temperatures was investigated and the B-stage PI powders prepared by thermally baking the PAE resins at 220°C are nearly fully imidized. The viscosities of the B-stage PI powders and the mechanical and thermal properties of the cured PI resins were optimized by varying the molar ratio of the two diamines. The cured PI resins possess low and steady dielectric constants ( Dk) below 3.0 and dielectric dissipation factors ( Df) of less than 0.01 at high frequency of 1–12 GHz. Furthermore, the quartz fiber cloth-reinforced semi-aromatic thermosetting PI composites (QF/PI) exhibit excellent dielectric performance, good heat resistance, and mechanical properties. At a high frequency of 1–12 GHz, the Dk of QF/PI-4 is stable in the range of 3.16–3.2, and the Df is stable in the range of 0.0026–0.0046. These results suggest the potential of the semi-aromatic QF/PI for use in high-frequency IC boards.

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 537
Author(s):  
Meng-Ge Huangfu ◽  
Deng-Xiong Shen ◽  
Xin-Xin Zhi ◽  
Yan Zhang ◽  
Yan-Jiang Jia ◽  
...  

The rapid development of advanced high-frequency mobile communication techniques has advanced urgent requirements for polymer materials with high-temperature resistance and good dielectric properties, including low dielectric constants (low-Dk) and low dielectric dissipation factors (low-Df). The relatively poor dielectric properties of common polymer candidates, such as standard polyimides (PIs) greatly limited their application in high-frequency areas. In the current work, benzoxazole units were successfully incorporated into the molecular structures of the fluoro-containing PIs to afford the poly(imide-benzoxazole) (PIBO) nano-fibrous membranes (NFMs) via electrospinning fabrication. First, the PI NFMs were prepared by the electrospinning procedure from organo-soluble PI resins derived from 2,2′-bis(3,4-dicarboxy-phenyl)hexafluoropropane dianhydride (6FDA) and aromatic diamines containing ortho-hydroxy-substituted benzamide units, including 2,2-bis[3-(4-aminobenzamide)-4-hydroxylphenyl]hexafluoropropane (p6FAHP) and 2,2-bis[3-(3-aminobenzamide)-4-hydroxyphenyl]hexafluoropropane (m6FAHP). Then, the PI NFMs were thermally dehydrated at 350 °C in nitrogen to afford the PIBO NFMs. The average fiber diameters (dav) for the PIBO NFMs were 1225 nm for PIBO-1 derived from PI-1 (6FDA-p6FAHP) precursor and 816 nm for PIBO-2 derived from PI-2 (6FDA-m6FAHP). The derived PIBO NFMs showed good thermal stability with the glass transition temperatures (Tgs) over 310 °C and the 5% weight loss temperatures (T5%) higher than 500 °C in nitrogen. The PIBO NFMs showed low dielectric features with the Dk value of 1.64 for PIBO-1 and 1.82 for PIBO-2 at the frequency of 1 MHz, respectively. The Df values were in the range of 0.010~0.018 for the PIBO NFMs.


2018 ◽  
Vol 9 (21) ◽  
pp. 2913-2925 ◽  
Author(s):  
Ming Zeng ◽  
Jiangbing Chen ◽  
Qingyu Xu ◽  
Yiwan Huang ◽  
Zijian Feng ◽  
...  

The effects of the reaction solvent on the preparation, polymerization kinetics, and high-frequency dielectric properties of aliphatic main-chain benzoxazine copolymers were investigated.


2012 ◽  
Vol 24 (8) ◽  
pp. 683-691 ◽  
Author(s):  
Cheng-Yuan Shang ◽  
Xiao-Juan Zhao ◽  
Xin Yang ◽  
Ying Zhang ◽  
Wei Huang

A novel epoxy resin containing trifluoromethyl and pendant polyfluorinted phenyl groups, 1,1-bis[4-(2,3-epoxypropoxy)phenyl]-1-(3,4,5-trifluorophenyl) -2,2,2-trifluoroethane (6FEP) was synthesized and characterized. The reactivtiy of 6FEP with two aromatic diamines, 4,4′-diaminodiphenyl methane (DDM) and 1,4-bis(4-amino-2-trifluoromethylphenoxy) benzene (6FAPB), and the properties of the cured 6FEP were investigated and compared with those of the commonly used epoxy resin diglycidyl ether of bisphenol A (DGEBA). The experimental results indicated that 6FEP showed lower reactivity than DGEBA. The cured 6FEP exhibited good thermal stabilities with decomposition temperature at 5% weight loss of 374–397°C, high glass transition temperature of 159–177°C and good mechanical properties. The cured 6FEP epoxy resin also showed low dielectric constants at 1 MHz in the range of 3.2–3.4 and dielectric dissipation factors (tan δ) in the range of 2.10–2.48 × 10−3. Moreover, the cured 6FEP epoxy resins exhibited higher surface hydrophobicity and lower moisture absorption compared with DGEBA. The improved dielectric properties and hydrophobic properties of the cured 6FEP epoxy resin could be attributed to the introduction of trifluoromethyl and pendant polyfluorinated phenyl groups into the molecular structure of the epoxy resin.


2019 ◽  
Vol 1 (4) ◽  
pp. 625-630 ◽  
Author(s):  
Jiangbing Chen ◽  
Ming Zeng ◽  
Zijian Feng ◽  
Tao Pang ◽  
Yiwan Huang ◽  
...  

Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 130
Author(s):  
Carlos Corona-García ◽  
Alejandro Onchi ◽  
Arlette A. Santiago ◽  
Araceli Martínez ◽  
Daniella Esperanza Pacheco-Catalán ◽  
...  

The future availability of synthetic polymers is compromised due to the continuous depletion of fossil reserves; thus, the quest for sustainable and eco-friendly specialty polymers is of the utmost importance to ensure our lifestyle. In this regard, this study reports on the use of oleic acid as a renewable source to develop new ionomers intended for proton exchange membranes. Firstly, the cross-metathesis of oleic acid was conducted to yield a renewable and unsaturated long-chain aliphatic dicarboxylic acid, which was further subjected to polycondensation reactions with two aromatic diamines, 4,4′-(hexafluoroisopropylidene)bis(p-phenyleneoxy)dianiline and 4,4′-diamino-2,2′-stilbenedisulfonic acid, as comonomers for the synthesis of a series of partially renewable aromatic-aliphatic polyamides with an increasing degree of sulfonation (DS). The polymer chemical structures were confirmed by Fourier transform infrared (FTIR) and nuclear magnetic resonance (1H, 13C, and 19F NMR) spectroscopy, which revealed that the DS was effectively tailored by adjusting the feed molar ratio of the diamines. Next, we performed a study involving the ion exchange capacity, the water uptake, and the proton conductivity in membranes prepared from these partially renewable long-chain polyamides, along with a thorough characterization of the thermomechanical and physical properties. The highest value of the proton conductivity determined by electrochemical impedance spectroscopy (EIS) was found to be 1.55 mS cm−1 at 30 °C after activation of the polymer membrane.


Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4017
Author(s):  
Dorota Szwagierczak ◽  
Beata Synkiewicz-Musialska ◽  
Jan Kulawik ◽  
Norbert Pałka

New ceramic materials based on two copper borates, CuB2O4 and Cu3B2O6, were prepared via solid state synthesis and sintering, and characterized as promising candidates for low dielectric permittivity substrates for very high frequency circuits. The sintering behavior, composition, microstructure, and dielectric properties of the ceramics were investigated using a heating microscope, X-ray diffractometry, scanning electron microscopy, energy dispersive spectroscopy, and terahertz time domain spectroscopy. The studies revealed a low dielectric permittivity of 5.1–6.7 and low dielectric loss in the frequency range 0.14–0.7 THz. The copper borate-based materials, owing to a low sintering temperature of 900–960 °C, are suitable for LTCC (low temperature cofired ceramics) applications.


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