Octa Aminopropylsilsesquioxane Research Articles

Imparting low dielectric constant and high modulus to polyimides via synergy between coupled silsesquioxanes and crown ethers

Our pilot research revealed that the dielectric constant of polyimide (PI) can be reduced and the modulus can be improved by assembling necklace-like interlocking complexes with crown ethers. Not only did we find that these properties of the PI complex still cannot adequately meet the demand of practical applications but also that there was a deterioration in its thermal stability. A functional octa(aminopropyl)silsesquioxane (OAPrS) with a significantly rigid Si-O-Si cage was incorporated into an 18-crown-6 (CE6)-PI (CE6-PI) complex to produce inorganic-organic OAPrS/CE6-PI nanocomposites. By exploiting the synergetic effect of OAPrS and CE6, most properties of the PI were clearly improved. In the case of 3.9 wt% OAPrS and 7.8 wt% CE6, the dielectric constant of PI was reduced by 30%, and Young's modulus and the tensile strength were increased by 106% and 23%, respectively. In addition, the thermal stability of the CE6-PI complex was modified, and its 5% weight loss temperature and glass transition temperature were increased by 31.2 and 11.2 °C, respectively, with the incorporation of 3.9 wt% OAPrS. The indispensable nano-reinforcing role of aggregated OAPrS crystal in the nanocomposite was carefully analysed and verified.

Phosphorus‐containing polyhedral oligomeric silsesquioxane/polyimides hybrid materials with low dielectric constant and low coefficients of thermal expansion

ABSTRACTNovel 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.