Synthesis, polymerization kinetics, and high-frequency dielectric properties of novel main-chain benzoxazine copolymers

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

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Low-Dissipation Thermosets Derived from Oligo(2,6-dimethyl phenylene oxide)-containing Benzoxazines

10.20944/preprints201803.0110.v1 ◽

2018 ◽

Author(s):

Chien-Han Chen ◽

Kuan-Wei Lee ◽

Ching-Hsuan Lin ◽

Tzong-Yuan Juang

Keyword(s):

Dielectric Properties ◽

Nucleophilic Substitution ◽

Catalytic Hydrogenation ◽

High Frequency ◽

Main Chain ◽

Dissipation Factor ◽

Insulating Materials ◽

Phenylene Oxide ◽

Low Dissipation ◽

Chain Type

Poly(2,6-dimethyl phenyl oxide) (PPO) is known for its low dissipation factor. To achieve insulating materials with low dissipation factor for high-frequency communication application, a monomer-type benzoxazine (P-APPO) and a main-chain-type benzoxazine (BPA-APPO) were prepared from an amine end-capped oligo (2,6-dimethyl phenylene oxide) (APPO). The APPO was prepared from a nucleophilic substitution of a phenol-end capped oligo (2,6-dimethyl phenylene oxide) (a commercial product, SA 90) with fluoronitrobenzene, and followed by catalytic hydrogenation. After self-curing or curing with a dicyclopentadiene-phenol epoxy (HP 7200), thermosets with high-Tg and low-dissipation factor can be achieved. Furthermore, the resulting epoxy thermosets show better thermal and dielectric properties than those of epoxy thermoset cured from its precursor SA90, demonstrating it is a successful modification in simultaneously enhancing the thermal and dielectric properties.

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Sintering, Microstructure, and Dielectric Properties of Copper Borates for High Frequency LTCC Applications

Materials ◽

10.3390/ma14144017 ◽

2021 ◽

Vol 14 (14) ◽

pp. 4017

Author(s):

Dorota Szwagierczak ◽

Beata Synkiewicz-Musialska ◽

Jan Kulawik ◽

Norbert Pałka

Keyword(s):

Dielectric Properties ◽

Dielectric Permittivity ◽

High Frequency ◽

Ceramic Materials ◽

Sintering Behavior ◽

Terahertz Time Domain Spectroscopy ◽

Very High Frequency ◽

X Ray ◽

Low Dielectric ◽

Very High

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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An impregnation-reduction method to prepare graphite nanosheet/alumina composites and its high-frequency dielectric properties

Rare Metals ◽

10.1007/s12598-015-0595-1 ◽

2015 ◽

Vol 36 (3) ◽

pp. 205-208 ◽

Cited By ~ 3

Author(s):

Ke-Lan Yan ◽

Run-Hua Fan ◽

Min Chen ◽

Kai Sun ◽

Xu-Ai Wang ◽

...

Keyword(s):

Dielectric Properties ◽

High Frequency ◽

Reduction Method ◽

Graphite Nanosheet ◽

Alumina Composites

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Multistructural Network Design Enables Polybenzoxazine to Achieve Low-Loss-Grade Super-High-Frequency Dielectric Properties and High Glass Transition Temperatures

Industrial & Engineering Chemistry Research ◽

10.1021/acs.iecr.1c03846 ◽

2021 ◽

Author(s):

Ming Zeng ◽

Dengru Tan ◽

Zijian Feng ◽

Jiangbing Chen ◽

Xiang Lu ◽

...

Keyword(s):

Glass Transition ◽

Dielectric Properties ◽

Network Design ◽

High Frequency ◽

Transition Temperatures ◽

Low Loss ◽

Glass Transition Temperatures ◽

Super High Frequency

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LOW-TEMPERATURE ION-PLASMA DEPOSITION TECHNOLOGY OF NANOSTRUCTURED FILMS OF ALUMINUM AND BORON NITRIDES

Optoelektronìka ta napìvprovìdnikova tehnìka ◽

10.15407/iopt.2021.56.097 ◽

2021 ◽

Vol 56 ◽

pp. 97-107

Author(s):

M. S. Zayats ◽

Keyword(s):

Dielectric Properties ◽

Low Temperature ◽

Magnetron Sputtering ◽

High Frequency ◽

Plasma Deposition ◽

Heating Temperature ◽

Substrate Heating ◽

Ion Plasma ◽

Technological Cycle ◽

Physical And Chemical

A low-temperature (substrate heating temperature up to 400 °C) ion-plasma technology for the formation of nanostructured AlN and BN films by the method of high-frequency reactive magnetron sputtering of the corresponding targets has been developed (the modernized installation "Cathode-1M"), which has in its technological cycle the means of physical and chemical modification, which allow to purposefully control the phase composition, surface morphology, size and texture of nanocrystalline films. The possibility of using the method of high-frequency magnetron sputtering for deposition of transparent hexagonal BN films in the nanoscale state on quartz and silicon substrates is shown. Atomic force microscopy (AFM) has shown that AlN films can have an amorphous or polycrystalline surface with grain sizes of approximately 20-100 nm, with the height of the nanoparticles varying from 3 to 10 nm and the degree of surface roughness from 1 to 10 nm. It was found that the dielectric penetration of polycrystalline AlN films decreases from 10 to 3.5 at increased frequencies from 25 Hz to 1 MHz, and the peak tangent of the dielectric loss angle reaches 0.2 at 10 kHz. Such features indicate the existence of spontaneous polarization of dipoles in the obtained AlN films. Interest in dielectric properties in AlN / Si structures it is also due to the fact that there are point defects, such as nitrogen vacancies and silicon atoms, which diffuse from the silicon substrate during synthesis and play an important role in the dielectric properties of AlN during the formation of dipoles. The technology makes it possible, in a single technological cycle, to produce multilayer structures modified for specific functional tasks with specified characteristics necessary for the manufacture of modern electronics, optoelectronics and sensorics devices. It should also be noted that the technology of magnetron sputtering (installation "Cathode-1M") is highly productive, energetically efficient and environmentally friendly in comparison with other known technologies for creating semiconductor structures and allows them to be obtained with minimal changes in the technological cycle.

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