Influence of morphological and conformational changes on the molecular mobility in poly(ethylene naphthalene‐2,6‐dicarboxylate)
Résumé
Abstract Dynamic electric (DEA) and mechanical (DMA) analyses were combined to explore the relaxational processes in amorphous and semicrystalline poly(ethylene naphthalene‐2,6‐dicarboxylate) (PEN) samples. Differential scanning calorimetry measurements were carried out to investigate the crystallinity of the samples following isothermal annealing treatment at 443 K. The two secondary relaxations β and β*, the main α relaxation, as well as the ρ‐relaxational process, were revealed by both electric and mechanical viscoelastic responses of the PEN samples. DMA results clearly identified the above T α loss factor peak, ρ, as a probe of the cold crystallization. However, the association of both DMA and DEA investigations pointed out that electric and non‐electric aspects might govern the ρ‐process.