Binary polymer blend of ArPTU/PI with advanced comprehensive dielectric properties and ultra‐high thermally stability

Abstract

Flexible high‐temperature polymeric dielectrics with advanced dielectric properties are urgently demanded in various applications. In this work, series of polymer blend films were prepared from aromatic polythiourea (ArPTU) and polyimide (PI). The experimental results revealed that the blend films were properly engineered to achieve higher breakdown strength, greater dielectric constant, and larger energy density than pure PI film. For instance, the optimum property was obtained from the blend film with 10 wt% ArPTU, exhibiting prominent dielectric properties (K = 4.52, Eb = 443 MV/m), enhanced energy density (4.00 J/cm3) as well as excellent heat resistance (Tg = 419°C). In addition, stable dielectric properties at broad temperature range from −50 to 250°C were also acquired. It is deduced that the good compatibility from ArPTU and PI with similar polarity are responsible for the improved properties. The superior comprehensive properties which combine the advantages of ArPTU and PI suggest the potential applications of ArPTU/PI blend film in high‐temperature dielectric areas.

High-temperature energy storage performances of “isomer-like” polyimide and its thermoplastic polyurethane blending system

“…6(c). 22,23,[26][27][28][29][30][31] The U e of the 3% TPU/i-PI film reported in this work is much higher than all other PI blend films at 25 1C. A high U e value is also obtained at 150 1C, and very few all-organic PI blend films have been reported at this temperature.…”

“…The interchain space of polymers can be reflected by calculating the d value in the Bragg equation (2 d sin θ = nλ ). 22 Compared with the common PI film ( d = 4.48 Å), the i-PI film has a smaller d of 3.88 Å. Fig.…”

“…Typically, 4,4 0 -diaminodiphenyl ether (ODA) and pyromellitic dianhydride (PMDA) are most commonly used to synthesize polyimide (common PI). [22][23][24][25] However, its longer p-p conjugation is favorable for the formation of electronic conduction paths, which greatly reduces the U e and efficiency (Z) at high temperatures. In addition, its rigid structure leads to a lower packing density, and the resulting larger interchain space (d) facilitates carrier migration and reduces its E b .…”

“…In addition, aromatic polythiourea (ArPTU) molecular chains were embedded into PI molecular chains, and the chain spacing between adjacent molecular chains was reduced in the obtained blend (ArPTU/PI), which was also beneficial to improve the dielectric properties. 22 The above studies achieved remarkable dielectric and energy storage properties through the regulation of molecular chains. Unfortunately, the influence of polymer interchain space on its high-temperature capacitive performance has not been systematically explored.…”

Novel cardo‐type heat‐resistant polyimides bearing 9H‐xanthene and polymer‐based nanocomposite consisting of NH2‐terminated TiO2: Synthetic strategies, extraction of methylene blue dye, and biological activities

“…[12][13][14] High-performance polymers as polymer matrices can be ideal support for synthesis of composites. 15,16 As an example of these materials, one can mention aromatic polyimides (PI)s, offering an extensive range of attributes, such as good barrier, non-flammability, transparency, thermal stability, low dielectric constant, high chemical resistance, and radiation resistance. PIs are widely applied in automobile, semiconductor, electronics, and aerospace fields, and so forth, due to their outstanding properties.…”