SYNTHESIS AND PROPERTIES OF FLUORINATED POLYIMIDES AND FLUORINATED POLY(IMIDE AMIDE)S CONTAINING PENDENT CYANO GROUPS

A series of fluorinated polyimides and fluorinated poly(imide amide)s containing pendent cyano groups were prepared and investigated to dete rmine their dielectric constants as a function of relative humidity an d thermal characteristics. The fluorinated polyimides and fluorinated poly(imide amide)s containing pendent cyano groups were prepared by re action of bis(4-aminophenoxy) benzonitriles with a fluorinated dianhyd ride and with a fluorinated di(acid chloride) containing preformed imi de rings. The properties of the fluorinated polyimides and fluorinated poly(imide amide)s containing pendent cyano groups were compared with those of fluorinated polyimides and fluorinated poly(imide amide)s pr epared from 1,3-bis(4-aminophenoxy)benzene. The introduction of the pe ndent cyano groups caused an increase in the dielectric constant and a n increase in the glass transition temperature of the polymers compare d with the polymers prepared without pendent cyano groups.