Dielectric investigation of semicrystalline morphology in poly (ether ether ketone) / poly (ether imide) blends

Dielectric relaxation spectroscopy has been used to examine the phase behavior of melt-crystallized poly (ether ether ketone) / poly (ether imide) blends. Two glass-rubber relaxations are observed in the crystallized blends corresponding to a mixed amorphous interlamellar phase, and a pure PEI phase residing in interfibrillar regions. Comparison of the relaxation characteristics of the interfibrillar phase with those of pure PEI indicate that the PEI chains in the blend experience a range of local relaxation environments, and that the observed relaxation encompasses a spectrum of PEI segregation sizescales ranging from the interlamellar (nanometer scale) to the interfibrillar/interspherulitic (micron scale).