Synergistic Enhancement of Mechanical and Dielectric Properties in Transparent Polyimides by Regulating Hydrogen Bonding and Microbranched Cross-Linking Structure

ACS Applied Polymer Materials, Год журнала: 2024, Номер 6(17), С. 10738 - 10749

Опубликована: Авг. 28, 2024

The development of polyimide (PI) films with excellent mechanical properties and low dielectric constants is crucial for flexible optoelectronic devices printed circuit boards. Here, a method to improve the decrease constant PI reported by introducing synergistic effect between hydrogen bonding (H-bonding) microbranched cross-linking structures. A triamine monomer (4,4′,4″-(1H-imidazole-2,4,5-triyl) trianiline, DTI) acting as bond donor was designed synthesized. It then in situ polymerized commercial 3,3′,4,4′-biphenyl tetracarboxylic dianhydride (BPDA), 4,4′-(hexafluoroisopropylidene) diphthalic anhydride (6FDA), 4,4′-oxidianiline (ODA), 1,4-phenylenediamine (PDA) obtain four different films, BPDA/ODA/DTI, BPDA/PDA/DTI, 6FDA/ODA/DTI, 6FDA/PDA/DTI. With introduction DTI, corresponding exhibited high modulus coefficient thermal expansion (CTE). When DTI content optimized, several high-performance suitable electronic applications were achieved. At 10 MHz, 6FDA/PDA series decreased from 3.39 2.89, while increased 3.41 4.60 GPa. CTE BPDA/PDA reduced 8.61 0.27, reduction approximately 97%. Structural characterization, density functional theory (DFT), molecular dynamics (MD) simulations revealed competitive relationships bonds branched cross-links within chains. This approach offers strategy overcome performance trade-off films.

Язык: Английский

---

Acyloxy-Containing Fluorene- and Benzimidazole-Based Polyimides with Improved Solubility, Transparency, and Dielectric Properties by Postmodification

ACS Applied Polymer Materials, Год журнала: 2025, Номер unknown

Опубликована: Янв. 16, 2025

Polyimide (PI) films with a low dielectric constant (Dk) and dissipation factor (Df) at high frequency remain an intriguing study for the ever-increasing demand 5G high-frequency transmission. In this study, effective molecular design strategy preparing low-dielectric PI excellent overall performance is presented by simultaneously introducing acyloxy-containing fluorene-based Cardo structure rigid benzimidazole unit H-bonding site. Based on concept, series of different-length fluorene- benzimidazole-based PIs were easily prepared moderate postmodification hydroxyl-containing (PI–OH-NH). Because presence structures, all modified still possess decent thermal stability, mechanical properties, coefficient expansion (CTE) values. Introducing acyloxy side groups effectively reduces packing density chains increases fractional free volume, resulting in improving solubility, transparency, properties films. Testing results show that keep good solubility high-polar solvents display improved low-polar solvents. addition, transmittances 500 nm (T500) obviously increase to 84.0%–86.4% from 69.6% PI–OH-NH film. The Dk Df values 1 MHz reduce 2.57–3.42 0.0105–0.0210 3.58 0.0282 film, respectively. Similarly, 10 GHz also 2.68–2.91 0.0131–0.0227 3.20 0.0354 integrative make these favorable candidates interlayer insulation materials flexible circuit substrates microelectronics optoelectronic engineering industries.

Язык: Английский

---

Transparent Poly(amide-imide)s with Low Coefficient of Thermal Expansion from Trifluoromethylated Trimellitic Anhydride

Polymers, Год журнала: 2025, Номер 17(3), С. 309 - 309

Опубликована: Янв. 24, 2025

Making transparent aromatic polymers with high Tg and low thermal expansion behavior, like glass, is challenging. We report soluble poly(amide-imide)s (PAIs) dimensional stability synthesized from the new monomer, trifluoromethylated trimellitic anhydride. Insertion of trifluoromethyl (CF3) groups into polymer chains enhanced solubility optical properties without sacrificing stability. Model reactions were utilized to study how CF3 group in anhydride affects polymerization reaction diamine monomers, a series PAIs synthesized. All polar organic solvents can be solution-cast nearly colorless flexible freestanding films. The obtained PAI films possessed (Td5: 437–452 °C N2) transparency (84~87% transmittance at 550 nm). Interestingly, prepared this exhibited thermodimensional CTE values 9 26 ppm/°C. poly(amide-imide) film value finds its application display devices that require form factors.

Язык: Английский

---

Synthesis and Characterization of High Glass Transition Temperature Colorless Polyimides Containing Hydrogen Bonding Carbazole Diamine for Optoelectronic Devices

ACS Applied Polymer Materials, Год журнала: 2025, Номер unknown

Опубликована: Март 24, 2025

Maintaining ultrahigh heat resistance, a low thermal expansion coefficient (CTE), and adequate colorless transparency concurrently poses significant challenge for polyimides (CPIs), especially as substrate materials flexible optoelectronic devices. In this work, we designed synthesized hydrogen-bonding carbazole tetraphenyl aromatic diamine, 2,7-bis[2-trifluoromethyl-4-aminophenyl]-9H-carbazole (2,7-CPFDA). The corresponding polyimide (PI) films were via the copolymerization of 2,7-CPFDA 2,2′-bis(trifluoromethyl)benzidine (TFDB) with 3,3′,4,4′-biphenyltetracarboxylic dianhydride (BPDA) at varying molar ratios. All copolymer PI presented high resistance 5% weight loss temperatures (Td5) between 552 563 °C, glass transition (Tg) ranged from 354 to 380 °C. As content increased, CTE decreased 17.6 10.4 ppm K–1, while tensile modulus (E) rose 5.7 6.7 GPa, elongation break (ε) improved 5.4% 28%. When BPDA was substituted 9,10-diphenyl-9,10-bis(trifluoromethyl)-9,10-dihydroanthracene-2,3,6,7-tetraacid (6FDPDA) 4,4′-(hexafluoroisopropylidene)diphthalic anhydride (6FDA), CPI exhibited overall favorable properties. Notably, C–PI-7 Tg 456 excellent mechanical properties (E = ε 11.9%), (8.7 K–1), transmittance 450 nm (T450 86.1%), thereby meeting performance requirements electronic

Язык: Английский

---

Synthesis and properties of high heat-resistant transparent polyimides containing terphenyl skeleton

European Polymer Journal, Год журнала: 2025, Номер unknown, С. 113924 - 113924

Опубликована: Март 1, 2025

Язык: Английский

---

Ultra-heat resistance and low CTE polyimides with spirobis(indene)bis(benzoxazole)-benzimidazole unite for flexible substrate applications

European Polymer Journal, Год журнала: 2025, Номер unknown, С. 113923 - 113923

Опубликована: Март 1, 2025

Язык: Английский

---