Influence de la structure sur les propriétés mécaniques dynamiques de quelques polytéréphtalates de polyméthylèneglycol. Relaxations β et γ

The influence of structure, cristallinity and orientation on the β- and γ-relaxation mechanisms of several poly(α,ω-alkandiolterephthalates) has been investigated. The γ-relaxation consists of two main components involving molecular motions in the amorphous phase, and motions of CH₂ groups (glycolic residue) in the gauche or trans form. A third component involves movements of bigger groups. The β-relaxation at low frequencies can be compared with the dilatometric glass transition.