Chemically crosslinked polyimide-POSS hybrid: A dielectric material with improved dimensional stability and dielectric properties

Di-Cyclohexene Oxide Bridged by DDSQ: Preparation, Characterization, and Application as Fillers for Cyanate Ester Resin

In order to improve the dielectric properties of existing thermosetting resins, taking advantage of reactive fillers is a simple and feasible option. In this paper, we synthesized a new double epoxycyclohexane double-decker silsesquioxane (DEDDSQ), in which the structure of aliphatic epoxy resin introduced into DDSQ successfully, and the resulting structure of DEDDESQ is confirmed by Fourier transform infrared (FTIR), nuclear magnetic resonance (NMR) spectroscopy, and mass spectrometry (MS). Cyanate ester resin was selected as the case study for the application of DEDDSQ as reactive fillers. A CE/E51/DEDDSQ nanocomposite was fabricated by incorporating a small proportion of E51 resin and DEDDSQ into cyanate ester resin to enhance its comprehensive properties. X-ray diffraction (XRD) and energy-dispersive spectroscopy (EDS) analyses demonstrated that DEDDSQ dispersed uniformly within the resin matrix. Dynamic mechanical analysis (DMA) demonstrated that the CE/E51/8.0DEDDSQ nanocomposites exhibit excellent thermal properties. The glass transition temperature (Tg) of the nanocomposite was measured to be 264 °C, indicating its excellent thermal stability. Dielectric property measurements showed that the addition of DEDDSQ reduced the dielectric constant of the cyanate ester resin, with the CE/E51/8.0DEPOSS nanocomposite exhibiting a dielectric constant of 2.47 at 1 MHz.

Metal-organic cage crosslinked nanocomposites with enhanced high-temperature capacitive energy storage performance

Polymer dielectric materials are widely used in electrical and electronic systems, and there have been increasing demands on their dielectric properties at high temperatures. Incorporating inorganic nanoparticles into polymers is an effective approach to improving their dielectric properties. However, the agglomeration of inorganic nanoparticles and the destabilization of the organic-inorganic interface at high temperatures have limited the development of nanocomposites toward large-scale industrial production. In this work, we synthesize metal-organic cage crosslinked nanocomposites by incorporating self-assembled metal-organic cages with amino reaction sites into the polyetherimide matrix. The in-situ crosslinking by self-assembled metal-organic cages not only achieves a homogeneous distribution of inorganic components, but also constructs robust organic-inorganic interfaces, which avoids the interfacial losses of conventional nanocomposites and improves the breakdown strength at elevated temperatures. Ultimately, the developed nanocomposites exhibit exceptionally high energy densities of 7.53 J cm-3 (150 °C) and 4.55 J cm-3 (200 °C) with charge-discharge efficiency of 90%.

The Recent Advances of Polymer-POSS Nanocomposites With Low Dielectric Constant

This study provides a comprehensive overview of the preparation methods for polyhedral oligomeric silsesquioxane (POSS) monomers and polymer/POSS nanocomposites. It focuses on the latest advancements in using POSS to design polymer nanocomposites with reduced dielectric constants. The study emphasizes exploring the potential of POSS, either alone or in combination with other materials, to decrease the dielectric constant and dielectric loss of various polymers, including polyimides, bismaleimide resins, poly(aryl ether)s, polybenzoxazines, benzocyclobutene resins, polyolefins, cyanate ester resins, and epoxy resins. In addition, the research investigates the impact of incorporating POSS on improving the thermal properties, mechanical properties, surface properties, and other aspects of these polymers. The entire study is divided into two parts, discussing systematically the role of POSS in reducing dielectric constants during the preparation of POSS composites using both physical blending and chemical synthesis methods. The goal of this research is to provide valuable strategies for designing a new generation of low dielectric constant materials suitable for large-scale integrated circuits in the semiconductor materials domain.

Polyimide/crown ether composite film with low dielectric constant and low dielectric loss for high signal transmission

Dielectric properties of polyimide (PI) are constrained by its inherent molecular structure and inter-chain packing capacities. The compromised dielectric properties of PI, however, could be rescued by introducing trifluoromethyl and forming a host-guest inclusion complex with the introduction of crown ethers (CEs). Herein, we report PI/crown ether composite films as a communication substrate that could be applied under high frequency circumstances. In this work, three kinds of bisphenol A-containing diamine (2,2'-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[4-(2-methyl-4-aminophenoxy)phenyl]propane, and 2,2-bis[4-(2-trifluoro methyl-4-aminophenoxy)phenyl]propane) are synthesized and polymerized with 4,4'-(hexafluoroisopropylidene)diphthalic anhydride to prepare low-dielectric PI films by means of thermal imidization. Crown ethers are introduced into the PI with different mass fractions to obtain three series of PI films. Following the combination of trifluoromethyl into the molecular chain of PI, high frequency dielectric loss of modified PI films can be effectively reduced. The properties of these materials (especially the dielectric properties) are thoroughly explored by crown ether addition. The results show that the crown ether addition process can offer crown ethers with increased free volume of PI matrix, thus allowing them to generate a special necklace-like supramolecular structure, which makes the crown ether disperse more uniformly in the PI matrix, resulting in improved dielectric properties. Importantly, the dielectric constant and dielectric loss of the composite films at high frequencies are remarkably reduced to 2.33 and 0.00337, respectively. Therefore, these composite films are expected to find extensive use as a 5G communication substrate at high frequencies in the future.