Blistering in carbon‐fiber‐filled fluorinated polyimide

Abstract A blistering study was performed on a fluorinated polyimide resin and its carbon‐fiber composite in an effort to determine the blister‐formation temperature and the influence of blisters on composite performance. The fluorinated resin and carbon‐fiber composite exhibit higher glass‐transition (435–455°C) and decomposition temperatures (above 520°C) than similar polyimide resins and their carbon‐fiber composites currently used. Two techniques were used to determine moisture‐induced blister formation. A transverse extensometer with quartz lamps as a heating source measured thickness expansion, as did a thermomechanical analyzer as a function of temperature. Both methods successfully measured the onset of blister formation with varying amounts of absorbed moisture (up to 3 wt%) in the samples. The polyimide resin exhibited blister temperatures ranging from 225 to 362°C, with 1.7–3.0 wt% absorbed moisture, and the polyimide composite had blister temperatures from 246 to 294°C with 0.5–1.5 wt% moisture. The blistering effects of the polyimide composites were found to have little correlation with modulus. POLYM. COMPOS., 2011. © 2010 Society of Plastics Engineers