Molecular mobility in poly(ethylene naphthalene 2,6 dicarboxylate)(PEN) dielectric films

The morphology of amorphous and uniaxially stretched PEN films have been characterized by DSC, WAXS and IR. Molecular mobility have been also studied by dynamic mechanical (DMS) and dielectric (DRS) spectroscopies: the /spl alpha/-relaxation is affected by orientation and crystallisation and is shifted to higher temperature, the /spl beta/*-relaxation is dependent on the orientation state and shows an increase of mobility after stretching whereas the last /spl beta/-relaxation shows no variation with drawing ratio or temperature of stretching. The influence of conduction mechanism upon orientation and crystallinity with temperature was studied by DC measurements in order to enable us to follow the mobility in situ during crystallization.