Rui Xiao's blog

This study investigates the influence of physical aging on the deformation behaviors of poly(ethylene terephthalate)-glycol. The polymers are subjected to a quenched and an annealed heat treatment, followed by deformation in tension. The digital image correlation (DIC) is used to capture the surface strain. The DIC results show that the deformation localization occurs in the post-yield strain softening region. The quenched and annealed polymers exhibit different localization types, representing as necking for quenched polymers and shear banding for annealed polymers.

The enthalpic response of amorphous polymers depends strongly on their thermal and deformation history. Annealing just below the glass transition temperature (Tg) causes a large endothermic overshoot of the isobaric heat capacity at Tg as measured by differential scanning calorimetry, while plastic deformation (cold work) can erase this overshoot and create an exothermic undershoot. This indicates that a strong coupling exists between the polymer structure, thermal response and mechanical deformation.

http://pubs.rsc.org/en/content/articlelanding/2014/ra/c4ra11412d#!divAbstract

R. Xiao, J. Guo, T. D. Nguyen RSC Adv., 2015,5, 416-423

http://pubs.rsc.org/en/content/articlelanding/2015/sm/c5sm00543d#!divAbstract

Freely available until Aug. 8th: http://authors.elsevier.com/a/1RDyK57Zjcoxj