Long Term Physical Aging of Amorphous Polymers

Serge Etienne (1) , Laurent David (2)

1 EEIGM - Ecole Européenne d'Ingénieurs en Génie des Matériaux
2 IMP-LMPB - Ingénierie des Matériaux Polymères - Laboratoire des Matériaux Polymères et des Biomatériaux

The dynamic properties of amorphous polymers is investigated during long term aging by means of high resolution low frequency mechanical spectroscopy. Two polymers are considered in this work, namely atactic polystyrene and quenched amorphous poly(ethylene naphtalate). It is shown that during aging at temperature higher than that of secondary relaxation but lower than that of primary one (if tested at 1Hz), the strength of the secondary relaxation first increases and then decreases for long aging times. This phenomenon is explained on the basis of concepts of (i) the cohesion heterogeneity of the amorphous network at the nanometric scale and (ii) cooperativity of molecular motions responsible for the secondary relaxations.

Mots clés: Physical Sciences

Domaines: Polymères

Serge Etienne, Laurent David. Long Term Physical Aging of Amorphous Polymers. Philosophical Magazine, 2007, 87 (3-5), pp.417-424. ⟨10.1080/14786430600847107⟩. ⟨hal-00513727⟩