scholarly journals Dielectric Property and Space Charge Behavior of Polyimide/Silicon Nitride Nanocomposite Films

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 322 ◽  
Author(s):  
Minghua Chen ◽  
Wenqi Zhou ◽  
Jiawei Zhang ◽  
Qingguo Chen
Keyword(s):  
Dielectric Constant ◽  
Silicon Nitride ◽  
Space Charge ◽  
Loss Tangent ◽  
Breakdown Strength ◽  
In Situ Polymerization ◽  
Composite Films ◽  
Polymeric Materials ◽  
Nanocomposite Films ◽  
Transport Channel

Polymeric materials have many applications in multiple industries. In this paper, silicon nitride nanoparticles (Si3N4) were incorporated into a polyimide (PI) matrix to obtain composite films via the in situ polymerization method. The Si3N4 nanoparticles were consistently scattered in the composites, and the thickness of PI/Si3N4 films was around 50 µm. The effects of nanoparticle content on the dielectric constant, loss tangent and breakdown strength were simultaneously studied. A 3 wt.% doped PI/Si3N4 film revealled excellent dielectric properties, a dielectric constant (ε) of 3.62, a dielectric loss tangent (tanδ) of 0.038, and a breakdown strength of 237.42 MV/m. The addition of Si3N4 formed an interface layer inside PI, resulting in a large amount of space charge polarization in the electric field. The space charge of materials from the microscopic point of view was analyzed. The results show that there are trapenergy levels in the composites, which can be used as a composite carrier center and transport channel, effectively improving the performance of a small amount of nanoparticles film.

Preparation and Dielectric Property of Al2O3 Surface Coating Modified BaTiO3/Polyimide Composite Film

2014 ◽  
Vol 908 ◽  
pp. 63-66
Author(s):  
Ya Jun Wang ◽  
Xiao Juan Wu ◽  
Chang Gen Feng
Keyword(s):  
Dielectric Constant ◽  
Barium Titanate ◽  
Composite Film ◽  
Breakdown Strength ◽  
In Situ Polymerization ◽  
Chemical Properties ◽  
Dielectric Strength ◽  
Xrd Analysis ◽  
Nanocomposite Films ◽  
The Matrix

Polyimide (PI) was chosen as the matrix of the composite, barium titanate/polyimide (BT/PI) nanocomposite films were prepared by in situ polymerization. In order to improve the dispersion and the physical-chemical properties of BT surface, barium titanate was modified by Al2O3coating and modified BT/PI nanocomposite films were prepared. The prepared modified BT was characterized by X-ray diffraction (XRD) analysis, and scanning electron microscopy (SEM), and the dielectric properties of the composites were characterized in detail. It was shown that surface modification with Al2O3is the chemical process and there were new substances forming. When BT was modified by 10 wt% Al2O3, the dielectric constant of the composite film was 18.96 (103Hz), the loss tangent 0.005, breakdown strength 70 MV·m-1, energy storage density 0.41 J·cm-3. The dielectric constant of BT modified by Al2O3is decreased while the dielectric strength of the modified BT/PI composite film is increased.

Microstructure and electrical properties in three-component (Al2O3–TiO2)/polyimide nanocomposite films

2010 ◽  
Vol 25 (12) ◽  
pp. 2384-2391 ◽  
Author(s):  
Jun-Wei Zha ◽  
Ben-Hui Fan ◽  
Zhi-Min Dang ◽  
Sheng-Tao Li ◽  
George Chen
Keyword(s):  
Glass Transition ◽  
Loss Factor ◽  
Breakdown Strength ◽  
In Situ Polymerization ◽  
Composite Films ◽  
Inorganic Nanoparticles ◽  
Nanocomposite Films ◽  
Proposed Model ◽  
Polyimide Nanocomposite

Polyimide (PI)-matrix composite films containing inorganic nanoparticles (nano-Al2O3 and nano-TiO2) have been fabricated. A proposed model is used to explain different structures of the (Al2O3–TiO2)/PI (ATP) films synthesized by employing in situ polymerization. Dependences of dielectric permittivities of the ATP films on frequency and temperature were studied. Results show the breakdown strength of the films decreases with prolonging the corona aging time. The incorporation of the nano-Al2O3 and nano-TiO2 particles significantly improves the corona resistance of the films. The corona aging also influences the infrared absorbance, the glass transition temperature (Tg), and loss factor (tanδ) of the ATP films.

Ultrahigh Energy Storage Performances of Polymer-based Nanocomposite via Interfaces Engneering

2020 ◽  
Author(s):  
Peng Wang ◽  
Zhongbin Pan ◽  
Weilin Wang ◽  
Jianxu Hu ◽  
Jinjun Liu ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Energy Storage ◽  
High Performance ◽  
Breakdown Strength ◽  
Composite Films ◽  
Power Electronic ◽  
Ultrahigh Energy

High-performance electrostatic capacitors are in urgent demand owing to the rapidly development of advanced power electronic applications. However, polymer-based composite films with both high breakdown strength (Eb) and dielectric constant...

Enhanced dielectric properties and thermostability in polyimide composites with core-shell structured polyimide@BaTiO3 nanoparticles

2021 ◽  
pp. 095400832199352
Author(s):  
Wei Deng ◽  
Guanguan Ren ◽  
Wenqi Wang ◽  
Weiwei Cui ◽  
Wenjun Luo
Keyword(s):  
Dielectric Constant ◽  
Dielectric Loss ◽  
Energy Density ◽  
Breakdown Strength ◽  
In Situ Polymerization ◽  
Dielectric Materials ◽  
High Energy ◽  
Amic Acid ◽  
High Energy Density ◽  
Core Shell

Polymer composites with high dielectric constant and thermal stability have shown great potential applications in the fields relating to the energy storage. Herein, core-shell structured polyimide@BaTiO3 (PI@BT) nanoparticles were fabricated via in-situ polymerization of poly(amic acid) (PAA) and the following thermal imidization, then utilized as fillers to prepare PI composites. Increased dielectric constant with suppressed dielectric loss, and enhanced energy density as well as heat resistance were simultaneously realized due to the presence of PI shell between BT nanoparticles and PI matrix. The dielectric constant of PI@BT/PI composites with 55 wt% fillers increased to 15.0 at 100 Hz, while the dielectric loss kept at low value of 0.0034, companied by a high energy density of 1.32 J·cm−3, which was 2.09 times higher than the pristine PI. Moreover, the temperature at 10 wt% weight loss reached 619°C, demonstrating the excellent thermostability of PI@BT/PI composites. In addition, PI@BT/PI composites exhibited improved breakdown strength and toughness as compared with the BT/PI composites due to the well dispersion of PI@BT nanofillers and the improved interfacial interactions between nanofillers and polymer matrix. These results provide useful information for the structural design of high-temperature dielectric materials.

scholarly journals Crystallization and Dielectric Properties of MWCNT /Poly(1-Butene) Composite Films by a Solution Casting Method

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 755
Author(s):  
Lingfei Li ◽  
Qiu Sun ◽  
Xiangqun Chen ◽  
Yongjun Xu ◽  
Zhaohua Jiang
Keyword(s):  
Dielectric Constant ◽  
Dielectric Properties ◽  
Dielectric Loss ◽  
Breakdown Strength ◽  
Composite Films ◽  
Conductive Filler ◽  
Interfacial Polarization ◽  
Solution Casting ◽  
Casting Method ◽  
Solution Casting Method

In this work, poly(1-butene) (PB-1) composite films with multi-walled carbon nanotubes (MWCNT) were prepared by a solution casting method. The relationship between the dielectric properties and the crystal transformation process of the films was investigated. It was indicated that there were two crystal forms of I and II of PB-1 during the solution crystallization process. With the prolongation of the phase transition time, form II was converted into form I. The addition of the conductive filler (MWCNT) accelerated the rate of phase transformation and changed the nucleation mode of PB-1. The presence of crystal form I in the system increased the breakdown strength and the dielectric constant of the films and reduced the dielectric loss, with better stability. In addition, the dielectric constant and the dielectric loss of the MWCNT/PB-1 composite films increased with the addition of MWCNT, due to the interfacial polarization between MWCNT and PB-1 matrix. When the mass fraction of the MWCNT was 1.0%, the composite film had a dielectric constant of 43.9 at 25 °C and 103 Hz, which was 20 times that of the original film.

Preparation and properties of thermostable well-functionalized graphene oxide/polyimide composite films with high dielectric constant, low dielectric loss and high strength via in situ polymerization

2015 ◽  
Vol 3 (18) ◽  
pp. 10005-10012 ◽  
Author(s):  
Xinliang Fang ◽  
Xiaoyun Liu ◽  
Zhong-Kai Cui ◽  
Jun Qian ◽  
Jijia Pan ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Graphene Oxide ◽  
Dielectric Loss ◽  
High Dielectric Constant ◽  
In Situ Polymerization ◽  
Composite Films ◽  
Functionalized Graphene ◽  
Functionalized Graphene Oxide ◽  
Low Dielectric ◽  
High Dielectric

Thermostable well-functionalized graphene oxide/polyimide composites with high dielectric constant and low dielectric loss were obtained at a low percolation threshold.

scholarly journals Polymer-Single Wall Carbon Nanotube Composites for Potential Spacecraft Applications

2001 ◽  
Vol 706 ◽  
Author(s):  
Cheol Park ◽  
Zoubeida Ounaies ◽  
Kent A. Watson ◽  
Kristin Pawlowski ◽  
Sharon E. Lowther ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Carbon Nanotube ◽  
Composite Films ◽  
Polymeric Materials ◽  
Polymer Nanocomposite ◽  
Weight Percent ◽  
Nanocomposite Films ◽  
Mechanical And Thermal Properties ◽  
Single Wall Carbon Nanotube ◽  
Single Wall Carbon

AbstractPolymer-single wall carbon nanotube (SWNT) composite films were prepared and characterized as part of an effort to develop polymeric materials with improved combinations of properties for potential use on future spacecraft. Next generation spacecraft will require ultra-lightweight materials that possess specific and unique combinations of properties such as radiation and atomic oxygen resistance, low solar absorptivity, high thermal emissitivity, electrical conductivity, tear resistance, ability to be folded and seamed, and good mechanical properties. The objective of this work is to incorporate sufficient electrical conductivity into space durable polyimides to mitigate static charge build-up. The challenge is to obtain this level of conductivity (10-8 S/cm) without degrading other properties of importance, particularly optical transparency. Several different approaches were attempted to fully disperse the SWNTs into the polymer matrix. These included high shear mixing, sonication, and synthesizing the polymers in the presence of pre-dispersed SWNTs. Acceptable levels of conductivity were obtained at loading levels less than one tenth weight percent SWNT without significantly sacrificing optical properties. Characterization of the nanocomposite films and the effect of SWNT concentration and dispersion on the conductivity, solar absorptivity, thermal emissivity, mechanical and thermal properties were discussed. Fibers and non-woven porous mats of SWNT reinforced polymer nanocomposite were produced using electrospinning.

The Effects of Coupling Agents on the Electrical Properties of Polyimide/TiO2 Hybrid Films

2014 ◽  
Vol 556-562 ◽  
pp. 371-374
Author(s):  
Kai Yan ◽  
Xiao Xu Liu
Keyword(s):  
Composite Film ◽  
Breakdown Strength ◽  
In Situ Polymerization ◽  
Composite Films ◽  
Electric Breakdown ◽  
Future Application ◽  
Breakdown Field ◽  
Coupling Agents ◽  
Hybrid Films ◽  
Simple Method

Polyamides (PI)-matrix composite films with inorganic nanoTiO2 have been fabricated by employing in situ polymerization. Before addition, TiO2 particles were firstly modified with coupling agents (KH550). The electric breakdown strength and micromorphology of hybrid films were characterized and investigated. Results indicated that nanoTiO2 particles were homogeneously dispersed in the PI matrix for the addition of coupling agents and the electric breakdown strength of PI/TiO2 composite films with KH550 were better than unmodified PI composite film. The breakdown field strength and tensile modulus of PI composite film with the inorganic content of 5 wt% were 200.1 (KV/mm). So the using coupling agent can effectively improve the compatibility and the homogenous dispersion of nanoTiO2 particles in PI matrix. Meanwhile, the procedure described here offers an effective and simple method to produce PI/TiO2 with excellent electrical needed for future application in electrical engineering field.

Fabrication, Morphology and Properties of Polyimide/Al2O3 Nanocomposite Films via Surface Modification and Ion-Exchange Technique

2018 ◽  
Vol 921 ◽  
pp. 91-98
Author(s):  
Ming Yu Zhang ◽  
Li Zhu Liu ◽  
K.S. Hui
Keyword(s):  
Ion Exchange ◽  
Composite Film ◽  
Original Film ◽  
Treatment Time ◽  
Breakdown Strength ◽  
Composite Films ◽  
Nanocomposite Films ◽  
Polyimide Films ◽  
Force Microscopy ◽  
Corona Resistance

Polyimide films with Al2O3composite layers were prepared by KOH solution surface hydrolysis, ion exchange and heat treatment. Scanning electron microscope (SEM), atomic force microscopy (AFM), X-ray diffractometry (XRD), thermo gravimetric analyzer (TGA), breakdown voltage tester, high frequency pulse voltage machine were performed to characterize the micromorphology, thermal stability, mechanical properties, electric breakdown strength, and corona resistance time of composite films. Results indicated that the thermal properties of the composite film are better than the original film. The corona resistance time of the composite film was longer than that of the pristine film. The composite film had the longest corona resistance time and reached 101.2min while the KOH treatment time was 90min.

scholarly journals Thermal and electrical properties of polyimide/PANI nanofiber composites prepared via in situ polymerization

2018 ◽  
Vol 36 (2) ◽  
pp. 283-287
Author(s):  
Aseel A. Kareem
Keyword(s):  
In Situ Polymerization ◽  
Composite Films ◽  
Nanocomposite Films ◽  
X Ray Diffraction ◽  
Nanofiber Composite ◽  
X Ray ◽  
Thermal And Electrical Properties ◽  
Ft Ir ◽  
Thermal Stability Of

Abstract Polyimide/polyaniline nanofiber composites were prepared by in situ polymerization with various weight percentages of polyaniline (PANI) nanofibers. X-ray diffraction (XRD) and Fourier transform infrared spectra (FT-IR), proved the successful preparation of PANI nanofiber composite films. In addition, thermal stability of PI/PANI nanofiber composites was superior relative to PI, having 10 % gravimetric loss in the range of 623 °C to 671 °C and glass transition temperature of 289 °C to 297 °C. Furthermore, the values of the loss tangent tanδ and AC conductivity σAC of the nanocomposite films were notably higher than those of pure polyimide. The addition of 5 wt.% to 15 wt.% PANI nanofiber filler enhanced the activation energy of PI composites from 0.37 eV to 0.34 eV.

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