A new insight in the dynamo-mechanical behavior of poly(ethylene terephthalate)

Dynamic mechanical experiments performed on a semicrystalline sample of poly(ethylene terephthalate) evidenced the relaxation processes (alpha and beta) that occur in the polymer. Multifrequency experiments were used both in order to calculate the apparent activation energy of relaxation and to point out how the dynamic conditions alter not only the main relaxations, but the overlapping melting/recrystallization events that succeed after the glass transition. Heating rate seems to affect these phenomena in a way similar to frequency. Also, a consecutive heating step was carried out to support the statements. (C) 2010 Elsevier Ltd. All rights reserved.