Dielectric Constant, Thermal and Mechanical Properties of Ladder‐Like Polypropylsilsesquioxane/Crown Ether‐Polyimide Nanocomposites

Peng

ACS Appl. Polym. Mater.

et al. 2022

Self Cite

At present, high-performance liquid crystalline polyesters with a good processability, low dielectric constant, and low dielectric loss at a high frequency (GHz) are in high demand ascribed to the rapid development of high-speed communication technology. Here, an imide dicarboxylic acid (IA) with a bulky phenyl side group is designed and synthesized. It is then copolymerized with 4-hydroxybenzoic acid (HBA), isophthalic acid (IPA), 4,4′-dihydroxybipheny (BP), and 4,4′-dihydroxydiphenyl ether (ODP) via solution polycondensation to obtain liquid crystalline poly(ester imide)s (LCPEIs). By controlling the feeding ratio of IA, the solubility, thermal stability, mechanical properties, and dielectric properties of the LCPEIs are tunable. When the molar fraction of IA reaches or exceeds 5%, the obtained LCPEIs are soluble in ordinary organic solvents, such as chloroform, N,N-dimethylformamide, N-methyl-2-pyrrolidinone, and so forth, which allows a simple solution casting to prepare isotropic LC films. The nematic LCPEIs show high glass transition temperatures (T g > 200 °C) but relatively low melting temperatures and isotropization temperatures (T m and T i, <340 °C). The LCPEI prepared with 10 mol % IA shows excellent combined properties, whose ηinh, M n (GPC), T g, T m, T i, T d 5%, tensile strength, tensile modulus, water uptake, dielectric constant, and dielectric loss (at 10 GHz) are 0.92 dL g–1, 20,900 g mol–1, 218 °C, 268 °C, 330 °C, 458 °C, 80.5 MPa, 4.0 GPa, 0.39%, 3.07, and 0.006, respectively. These LCPEIs can be promising candidates for flexible copper-clad laminate substrates.

Section: Results and Discussionmentioning

confidence: 99%

“…The possible reason is the significant decrease in the content of a highly polarized imide group in the structures. 34,35 Obviously, the water-absorbing capacity of the LCPEIs films enhances gradually with an increasing content of imide units.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

Soluble Liquid Crystalline Poly(ester imide)s with High Glass Transition Temperatures and Improved Dielectric Properties

Peng

ACS Appl. Polym. Mater.

et al. 2022

Self Cite

J of Applied Polymer Sci

“…In recent years, polyimide (PI) films, due to their excellent mechanical properties, heat resistance and dielectric properties, have been widely used as dielectric materials and electronic packaging materials in the field of microelectronics. [1][2][3][4][5] However, with the rapid development of information technology and microelectronics industry, the integrated circuit continues to shrink and the lead density on the circuit board continues to increase, which inevitably leads to the problems such as time delay, crosstalk noise and power loss between the interconnect capacitors. 6,7 Therefore, this field increasingly needs materials with ultra-low dielectric constant or low dielectric constant to meet the high integration degree of the circuit board.…”

Section: Introductionmentioning

confidence: 99%

Polyimide hollow glass microspheres composite films with low dielectric constant and excellent thermal performance

Cao

Wen

Song

et al. 2021

Nowadays, polyimide (PI) with low dielectric constant is expected to be widely applied in microelectronics. For this reason, hollow glass microspheres (HGM) modified by silane coupling agent KH-550 (K-HGM), a series of HGM/PI and K-HGM/PI composite films with excellent thermal performance, hydrophobic and low dielectric constant were fabricated by in situ polymerization. The effect of HGM/K-HGM content on the properties of composite films was studied. The superior heat resistance of HGM can improve the thermal performance of composite films. Due to silane coupling agent KH-550, K-HGM exhibits a good interfacial compatibility with PI matrix and forms an interfacial adhesion region. With the HGM loading of 6%, comparing with pure PI films, the glass transition temperatures (T g) of composite films were dramatically increased by 32.3 C. Especially, the low dielectric constant of 2.21 and dielectric loss of 0.0059 at 1 MHz were obtained for the PI/K-HGM composite film with addition of 8 wt%. Thus, PI/K-HGM composite films show more excellent performance. The current work provides a promising solution for fabrication of PI with low dielectric constant and superior thermal performance that may be applied in microelectronics industry.

“…There were various fillers, e.g. nanoscale graphene fluoroxide, graphene oxide, graphite‐like carbon nitride, KIT‐6, polyhedral oligomeric silsesquioxane, amino functionalized polyhedral oligomeric silsesquioxane, ladder‐poly(propylsilsesquioxane), nanosized silica, SBA‐15, pure silica zeolite nanocrystals and graphene oxide blended with octa(aminophenyl) silsesquioxane,…”

Section: Introductionmentioning

confidence: 99%

Low dielectric constant polyimide mixtures fabricated by polyimide matrix and polyimide microsphere fillers

Qiu

2020

Polymer International

Polyimide microspheres were prepared via non-aqueous emulsion polymerization by using pyromellitic dianhydride (PMDA) as anhydride monomer and 2,2-bis(4-(4-aminophenoxy)phenyl)propane as amine monomer. The polyimide microspheres were well characterized by Fourier transform infrared spectroscopy, SEM and laser particle size analyzer. They were spherical in shape and monodisperse and their size was 31-33 ∼m. Polyimide mixtures formed by polyimide microspheres as fillers and polyimide composed of pyromellitic and dianhydride 4,4 0 -oxydianiline (ODA) as matrix were investigated with regard to thermal properties, dielectric properties and mechanical properties. With 10%-50% polyimide microspheres in the polyimide mixtures, the dielectric constants were 2.26-2.48 (1 MHz) and the loss tangents were 0.00663-0.00857 (1 MHz), which were both significantly lower than the values for ODA-PMDA polyimide. The decomposition temperature and glass transition temperature were above 440 and 290°C. The polyimide mixtures possessed excellent thermal resistance. When the percentage of polyimide microsphere addition was 30%, the polyimide mixtures had the largest tensile strength (128.50 MPa) and elongation at break (9.01%). These results indicate that the polyimide microspheres were used as both low dielectric fillers and reinforcing fillers.