A novel family of optically transparent fluorinated hyperbranched polyimides with long linear backbones and bulky substituents

Liu, Yu; Guo, Jinyu; Wang, Jiuyang; Zhu, Xiaoyu; Qi, Duo; Li, Wenze; Shen, Kunzhi

doi:10.1016/j.eurpolymj.2020.109526

Cited by 27 publications

(18 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Figure 3 compares the tensile modulus, total transmittance, and YI of CLPI-70 and CLPI-70/S-1.8 with those of previously reported optical films, including various conventional CLPIs prepared in this study. [15,[63][64][65][66][67][68][69][70][86][87][88][89][90][91][92][93] CLPI-70 has enhanced mechanical strength and optical properties compared to those of the reported optical films. Moreover, CLPI-70/S-1.8 has a tensile modulus of over 8.0 GPa, total transmittance close to 90%, and YI below 3.0.…”

Section: Mechanical and Optical Properties And Folding Reliabilitymentioning

confidence: 99%

Highly Transparent, Colorless Optical Film with Outstanding Mechanical Strength and Folding Reliability Using Mismatched Charge‐Transfer Complex Intensification

Ahn

Kim

Hong

et al. 2022

Adv Funct Materials

View full text Add to dashboard Cite

The development of flexible displays and electronics is hindered by the disadvantages of polymeric window films, such as low mechanical strength, poor optical properties, and lack of folding and rolling reliability. To overcome these critical limitations, a novel colorless polyimide window film is prepared in this study using the concept of charge‐transfer complex (CTC) intensification. The resulting window film has a tensile modulus of 8.4 GPa, total transmittance of ≈90%, and yellow index below 3, which is the best recorded balance between mechanical strength and optical properties for a highly flexible optical film. Unlike commercially available optical‐grade engineering plastic films and glass substrates, the prepared window film has both pencil hardness grade over 2H and folding reliability over 200 000 folding/unfolding cycles. These remarkable properties are attributed to the unique supramolecular structure with multiple hydrogen bonding and salt complexation interactions, which exhibits CTC intensification. The CTC intensification mechanism is also proposed in this study.

show abstract

Section: Mechanical and Optical Properties And Folding Reliabilitymentioning

confidence: 99%

Highly Transparent, Colorless Optical Film with Outstanding Mechanical Strength and Folding Reliability Using Mismatched Charge‐Transfer Complex Intensification

Ahn

Kim

Hong

et al. 2022

Adv Funct Materials

View full text Add to dashboard Cite

show abstract

Section: Introductionmentioning

confidence: 99%

“…Therefore, how to effectively reduce the coefficient of thermal expansion (CTE) of CPI films while improving transparency has become one of the important directions in the current research field. 26,27 Many strategies have been reported to reduce the CTE value of CPI films, such as introducing rigid rod structure into the main chain, 26,28,29 or adding inorganic fillers with inherently low CTE, but to obtain a lower CTE value, a higher filling coefficient is required, which significantly reduces the flexibility of CPI film. Another way to improve the thermal dimensional stability of CPI films is introducing hydrogen bonds into the PI main chain to induce tight stacking and segment orientation by enhancing the interaction between chains.…”

Section: Introductionmentioning

confidence: 99%

Transparent polyimide films with ultra-low coefficient of thermal expansion

Zhang

Yang

Piao

et al. 2022

High Performance Polymers

View full text Add to dashboard Cite

According to the application requirements of colorless transparent polyimide (CPI) film for low coefficient of thermal expansion (CTE) in the field of OLED display, the new aromatic dianhydride monomers with amide bond structure were synthesized, namely s-ABDA, i-ABDA, EADA. Furthermore, a series of CPI films were prepared by two-step method from the reaction of as-synthesized dianhydrides with 2.2′-bis (trifluoromethyl) −4.4′-diaminobiphenyl (TFMB) or trans-1.4′-cyclohexanediamine ( t-CHDA). Based on the analysis of performance results, the incorporation of amide group and biphenyl, benzene or ether bond into dianhydride monomer helped this new type of transparent polyimide film with excellent optical properties (T550 nm> 88%), great heat stability (CTE < 4.4 ppm/K; Tg > 314°C; Td5% > 478°C) and good mechanical strength (σ > 208 MPa). The film s-ABDA/TFMB showed ultra-low CTE value at 4.4 ppm/K, aligning with the maximum birefringence, indicating that the role of hydrogen bonding was of great benefit to the regulation of thermal expansion.

show abstract

“…Several studies have been reported to have reduced the dielectric properties of PI polymers while maintaining superior physical properties. , First, it has been proposed that the fluorinated and aliphatic-modified PIs can reduce polarization and introduce free volume. , Han et al decreased the dielectric constant to 2.78 at 1 MHz by introducing a hyperbranched fluorine unit into the main PI chain with a cross-linking agent . Feng et al incorporated two-dimensional fluoro-graphene sheets into PI composites to decrease the dielectric constant to 2.09 at 1 MHz .…”

Section: Introductionmentioning

confidence: 99%

Green and Facile Synthesis of Hybrid Composites with Ultralow Dielectric Properties from Water-Soluble Polyimide and Dual-Porous Silica Nanoparticles

Kim

Lee

Park

et al. 2022

ACS Appl. Mater. Interfaces

View full text Add to dashboard Cite

Here, we proposed an eco-friendly synthetic method for synthesizing hybrid composites with ultralow dielectric properties at high frequencies up to 28 GHz for true 5G communication from aqueous aromatic polyimide (PI) polymers and dual-porous silica nanoparticles (DPS). The "one-step" water-based emulsion template method was used to synthesize the macroporous silica nanoparticles (MPS). A substantially negative ζ potential was produced along the surface of MPS by the poly(vinylpyrrolidone)-based chemical functionalization, enabling excellent aqueous dispersion stability. The water-soluble poly(amic acid) (PAA), as a precursor to PI, was also "one-step" polymerized in an aqueous solution. The MPS were dispersed in a water-soluble PAA matrix to create the hybrid composite films using an entirely water-based approach. The compatibility between the PAA matrix and MPS was elucidated by investigating relatively diverse end-terminated PAAs (with either amine or carboxyl group). It was also discovered that, during a thermally activated imidization reaction, the MPS are in situ converted into the DPS with macro-and microporous structures (with a surface area of 1522.4 m 2 /g). The thermal, dielectric, mechanical, and morphological characteristics of each composite film were examined, while the amount of DPS in the PI matrix varied from 1 to 20 wt %. With the addition of 5 wt % DPS as an optimum condition, it showed ultralow dielectric properties, with the D k and D f being 1.615 and 0.003 at a frequency of 28 GHz, respectively, and compatible mechanical properties, with the tensile strength and elastic modulus being 78.2 MPa and 0.32 GPa, respectively. These results can comprehensively satisfy various physical properties required as a substrate material for 5G communication devices.

show abstract

A novel family of optically transparent fluorinated hyperbranched polyimides with long linear backbones and bulky substituents

Cited by 27 publications

References 45 publications

Highly Transparent, Colorless Optical Film with Outstanding Mechanical Strength and Folding Reliability Using Mismatched Charge‐Transfer Complex Intensification

Highly Transparent, Colorless Optical Film with Outstanding Mechanical Strength and Folding Reliability Using Mismatched Charge‐Transfer Complex Intensification

Transparent polyimide films with ultra-low coefficient of thermal expansion

Green and Facile Synthesis of Hybrid Composites with Ultralow Dielectric Properties from Water-Soluble Polyimide and Dual-Porous Silica Nanoparticles

Contact Info

Product

Resources

About