Polyimide/fluorinated silica composite films with low dielectric constant and low water absorption

In this study, KMnO4 was applied as an etchant to partially decompose the silica microspheres into mesoporous structures. 1H,1H,2H,2H-perfluorodecyltriethoxysilane was grafted onto the surface of the hollow silica. A fluorinated silica/polyimide hybrid material was prepared. Meanwhile, the influence of fluorinated silica on the dielectric property and moisture absorption property of the hybrid material was discussed. It is found that the fluorinated silica can lower the dielectric constant and hygroscopicity of the hybrid film. The fluorinated silica is characterized by strong hydrophobicity, good dispersibility, and good thermal stability. Even at a very low filling level of only 2 wt%, the dielectric constant of the polyimide hybrid is significantly reduced to 2.61 without sacrificing thermal stability. The water absorption rate of the polyimide hybrid film is reduced from approximately 3.1% to 2.1 wt%. Moreover, this provides a new idea for reducing the dielectric and water absorption properties of materials.

A non-enzymatic glucose sensor based on electrospun 3-D copper oxide micro-nanofiber network films using carboxylic-functionalized poly(arylene ether ketone)s as templates

3-D network films of rope-like CuO-MNFs with high surface-to-volume ratio were prepared. The product is a promising electrode material for fabrication of amperometric enzymeless glucose sensors.

Mixed Rigid and Flexible Component Design for High-Performance Polyimide Films

To develop the polyimide (PI) which is closely matched to the coefficient of the thermal expansion (CTE) of copper, a series of PIs are prepared from 5,4′-diamino-2-phenyl benzimidazole (DAPBI), 4,4′-diaminodiphenyl ether (ODA), and 3,3′,4,4′-benzophenonetetracarboxylic dianhydride (BTDA) using a sequential copolymerization, blade coating, and thermal imidization process. The physical properties of the PIs are effectively regulated and optimized by adjusting the ratio of the rigid DAPBI and flexible ODA components. By increasing the DAPBI content, thermal stability, dimensional stability, and mechanical properties, the resultant polymer is enhanced. PI-80 exhibits an excellent comprehensive performance, a glass transition temperature of 370 °C, and a tensile strength of 210 MPa. Furthermore, the CTE as calculated in the range 50–250 °C is ca. 19 ppm/K, which is equal to that of copper. A highly dimensionally stable, curl-free, and high T-style peel strength (6.4 N/cm) of copper/PI laminate was obtained by casting the polyamic acid onto copper foil (13 μm) and thermally curing at 360 °C, which indicates that it has the potential to be applied as an electronic film for flexible displays and flexible printed circuit boards. A structural rationalization for these remarkable properties is also presented.

Hybrid formation of graphene oxide–POSS and their effect on the dielectric properties of poly(aryl ether ketone) composites

Covalent functionalization of graphene oxide with aminopropylisobutyl polyhedral oligomeric silsesquioxane efficiently reduced the dielectric constant of the polymer matrix.

Preparation of poly(ether ketone)s having phenyl, biphenyl, and terphenyl side groups and comparison of their properties

Three kinds of bis(aromatic fluoride) compounds, 3,5-bis(4-fluorobenzoyl)biphenyl (1), 3,5-bis(4-fluorobenzoyl)-1,1′:4′,1″-terphenyl (2), and 3,5-bis(4-fluorobenzoyl)-1,1′:4′,1″:4″,1′′′-quaterphenyl (3), were synthesized by cross-coupling of the corresponding triflates with phenylboronic acid. Linear poly(ether ketone)s (1x, 2x, and 3x) having phenyl, biphenyl, and terphenyl side groups, respectively, were prepared by the polycondensation of the bis(aromatic fluoride) compounds with bisphenol A (a) and 4,4′-dihydroxybiphenyl (b) in N-methyl-2-pyrrolidone. The obtained poly(ether ketone)s were characterized by X-ray diffraction, differential scanning calorimetry, and thermogravimetry. The structure–property relationships of these poly(ether ketone)s were examined and compared with those of poly(ether ketone)s (4x) having no side group, which were prepared from 3,5-bis(4-fluorobenzoyl)benzene (4). The properties of the poly(ether ketone)s, solubilities, and thermal properties were compared and discussed based on the length of the side groups.

All-solid-state nanocomposite electrolytes composed of an ionic polymer with polar groups and surface-modified SiO2 nanoparticles for dye-sensitized solar cells

Polar groups on modified SiO₂ facilitate the ionization of DMPII and enhance the efficiency of DSCs.

Low-k and superior comprehensive property hybrid materials of a fluorinated polyimide and pure silica zeolite

FPI/A-PSZN hybrid materials with low-k and superior comprehensive properties are potentially useful in the microelectronic industry.

Electrospun carboxylic-functionalized poly(arylene ether ketone) ultrafine fibers

As a high-performance polymer, carboxylic-functionalized poly(arylene ether ketone)s (PCA-PAEK) was electrospun into ultrafine fibers and characterized. To optimize the process, a set of experiments were designed. As a result, the optimum condition was obtained and the polymer concentration was determined as the most important factor. Incidentally, the PCA-PAEK fibers were found to exhibit superabsorbent behavior. In order to investigate processing characteristics, PCA-PAEK fibers fabricated from different solution concentrations were employed and characterized. The results showed that porosity and changes in water contact angle and water absorbency decreased with an increase in concentration. In addition to a high water absorption capacity, the fibers exhibited good water retention and repeated water absorbency as well. The study on kinetics of water absorption and swelling behavior showed that the mechanism was dependent on the polymer concentration from which the fibers were electrospun. Moreover, both dry and wet PCA-PAEK fibers showed high mechanical properties. Due to these properties, the PCA-PAEK ultrafine fibers are potentially useful as a water-absorbent material.

Dielectric and thermal behaviors of POSS reinforced polyurethane based polybenzoxazine nanocomposites

The preparation of POSS reinforced polyurethane based polybenzoxazine nanocomposites as an interlayer low k dielectrics.

Design of lamellar structured POSS/BPZ polybenzoxazine nanocomposites as a novel class of ultra low-k dielectric materials

A novel class of lamellar structured polyhedral oligomeric silsesquioxane/bisphenol Z (POSS/BPZ) polybenzoxazine (PBz) nanocomposites was successfully designed by a facile one-step copolymerization technique.

A new polymer with low dielectric constant based on trifluoromethyl-substituted arene: preparation and properties

A polymer based on trifluoromethyl-substituted arene was synthesized with high molecular weight (M_n) of 62 000 by the Scholl reaction. The polymer film showed low dielectric constants of about 2.56 in a range of frequencies from 1 to 25 MHz. Moreover, the polymer revealed high thermostability and good mechanical properties, suggesting that the polymer had potential applications in the electronics industry.