Novel phosphorus-containing polyhedral oligomeric silsesquioxane (POSS)/polyimides (PI) hybrid materials with low dielectric constant and low linear coefficients of thermal expansion (CTE) were prepared and characterized. The POSS/PI hybrid materials were synthesized with octa(aminopropyl)silsesquioxane (OAPS) and a series of phosphorus-containing polyamide acids(PAA). The PAAs were synthesized with bis(4-aminophenoxy) phenyl phosphine oxide (BAPPO), 4,4’-diaminodiphenyl ether (ODA) and 3,3',4,4'-biphenyl tetracarboxylic diandhydride (BPDA). The structures and properties of the hybrid materials were characterized. And the effect of the phosphorus-containing structure on the POSS/PI hybrid materials was discussed. The dielectric constants and CTE of the hybrid materials were remarkably lower than that of the unmodified POSS/PI films. The lowest values of dielectric constant and CTE could achieve as low as 2.64 (1 MHz) and 27.45 ppm/K. Besides, the hybrid materials also had excellent thermal properties. The highest 5% weight loss temperature of the hybrid materials was as high as 580°C under air. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42611.

A series of copoly(aryl ether sulfone)s containing double-decker-shaped silsesquioxane (DDSQ) in the main chain was prepared. Toward this end, a novel diphenol polyhedral oligomeric silsesquioxane macromer was synthesized by hydrosilylation between 3,13-dihydro octaphenyl double-decker silsesquioxane (denoted dihydro DDSQ) and eugenol. The poly(aryl ether sulfone)s were synthesized from diphenol DDSQ, bisphenol A (BPA), and 4-fluorophenyl sulfone using a one-step high-temperature solution method. By adjusting the ratio of diphenol DDSQ to BPA, copolymers with variable DDSQ content in the main chains were obtained. With increased DDSQ content in the main chain, the glass transition temperature decreased based on differential scanning calorimetry, and anti-degradation was enhanced based on thermogravimetric analysis. Moreover, the dielectric constant κ of pure polymer (3.19 at 1 MHz) initially increased to 4.04 (DDSQ molar ratio = 10%), and then decreased to 2.68 at 1 MHz (DDSQ molar ratio = 100%). Crystallization behavior, solubility, and surface hydrophobicity were also investigated. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 780–788

The aromatic diphenol monomers, 4-(1-adamantyl)-1,3-benzene diol (AdRES) and 4-(6-(4-hydroxyphenyl)undecan-6-yl)phenol (BISPR5R5) were successfully synthesized and used to synthesize a new series of poly (aryl ether ketone) copolymers (AdRES-BISPR5R5-PEEKs) with different percentages of two diphenol monomers by nucleophilic aromatic substitution polycondensation. The structure of copolymers was confirmed using FTIR and ¹H NMR spectroscopy and their thermal and mechanical properties and solubilities were determined. It was found that the flexibility and toughness properties of the copolymers could be controlled by varying the molar ratio of diphenol monomers containing the pendent rigid adamantyl group and the flexible long side chains. They also showed low dielectric constants (κ = 2.50–2.88 at 1 MHz) and low water absorptions. It revealed that the symmetrical long aliphatic side chains were more conducive for reducing the polarity of the polymer chains, loosening the polymer packing, and subsequently reducing polymers' density and dielectric constants than the pendent rigid adamantyl group. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013