Synthesis and characterization of branched phenylethynyl-terminated polyimides

Sun, Wanlu; Gu, Junwei; Tian, Lidong; Pan, Yao; Zhang, Qiuyu

doi:10.1007/s10965-015-0735-1

Cited by 15 publications

(9 citation statements)

References 34 publications

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“…The bands near 1778 cm −1 and 1726 cm −1 can be ascribed to the asymmetrical and symmetrical stretching vibration of the C=O groups, respectively [22]. The characteristic stretching vibration peak at 1379 and 1116 cm −1 can be assigned to the C-N group, and the bending vibration peak at 720 cm −1 can be attributed to the imide group [23]. In addition, all the FTIR curves of the PI/Si 3 N 4 complexes present clear characteristic absorption peaks near 3533, 1647, 1074, 952 and 447 cm −1 , owing to the incorporation of Si 3 N 4 nanoparticles [24,25].…”

Section: Structure Characterization Of Pi/si 3 Nmentioning

confidence: 97%

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

et al. 2020

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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.

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Section: Structure Characterization Of Pi/si 3 Nmentioning

confidence: 97%

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

et al. 2020

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“…The difficulty comes from several reasons: a polymer performance is usually affected by several chemical and structural factors in a complicated way, while to vary one of these factors without changing the other factors demands systematic synthetic techniques. [10][11][12][13][14] High-performance polymers are used in applications demanding service at enhanced temperatures, while maintaining their structural integrity and an excellent combination of chemical, physical, and mechanical properties. 15 Among them, aromatic polyimides represent an increasing important class of materials in aerospace, microelectronics, and other industrial applications.…”

Section: Introductionmentioning

confidence: 99%

Effects of biopolyimide molecular design on their silica hybrids thermo-mechanical, optical and electrical properties

et al. 2018

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“…Porous polyimide (PI) has been widely used in the fields of chemical, mechanical and electronic because of its excellent thermal oxidation and mechanical properties including corrosion resistance and wear resistance (Ding et al, 2016;He et al, 2016;Ma et al, 2019;Sun et al, 2015). Consequently, PI composites are often used to make space bearing retainers because of the characteristics of low friction coefficient and selflubrication (Lv et al, 2015;Zhang, 2018).…”

Section: Introductionmentioning

confidence: 99%

The friction and wear behaviors of polyimide bearing retainer under point-contact condition

Zhang

Zhang²,

Zhou³

et al. 2020

ILT

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Purpose Random point-contact between the space bearing retainer and the rolling elements may cause wear of the space bearing retainer. The paper aims to clarify the friction and wear behaviors of polyimide bearing retainer under point-contact condition. Design/methodology/approach Space bearing retainers were cut into flat specimens and the tribological behaviors of the specimens were studied under point-contact condition using a friction and wear testing machine. Different sliding velocities and normal loads were used to simulate the running state of space bearing retainer. The wear behaviors of the space bearing retainer were analyzed by SEM and white light interferometer. Findings The friction coefficient of the polyimide composites decreased with increase in sliding velocity from 1 to 5 mm/s. Moreover, with increase in sliding velocity and normal load, the wear rate of the polyimide composites decreased and increased, respectively. Moreover, the wear behaviors of the polyimide composites were mainly determined by the combined actions of ploughing friction and adhesive friction. The lubricating properties of transfer film and wear debris were limited under point-contact condition. Practical implications The paper includes implications for the understanding of the wear mechanism of the polyimide composites space bearing retainer under point-contact condition and then to optimize space bearing retainer materials further. Originality/value Under point-contact condition, wear debris can hardly participate in the friction process because of limited contact area. Consequently, the wear debris has limited impact on the wear process to decrease the friction and wear. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-01-2020-0017/

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Synthesis and characterization of branched phenylethynyl-terminated polyimides

Abstract: A series of PEPA-TAP-ODA-6FDA branched phenylethynyl-terminated polyimides (BPIs) are successfully synthesized by incorporation of branching units into the linear PI. The molecular structures, thermal and rheological properties of the BPIs are investigated and characterized by FTIR, 1

Cited by 15 publications

References 34 publications

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

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

Effects of biopolyimide molecular design on their silica hybrids thermo-mechanical, optical and electrical properties

The friction and wear behaviors of polyimide bearing retainer under point-contact condition

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