Ageing of poly(ethyleneterephthalate) (PET)
The theoretical aspects of PET ageing have been рrеsented and the importance of free volume relaxation in this process accentuated. The results of studies on the effect of time, relative humidity and storage temperature as well as of relative viscosity of polymer on the changes in tensile yield and Dart Impact of PET have been presented and discussed. It has been shown that free volume relaxation has a detrimental effect on the mechanical properties of bottles, films and preforms of amorphous PET. In general, it can be concluded that it is a poor practice to store PET articles in hot humid conditions.
If you are interested in full versions of articles, please contact the editorial team of firstname.lastname@example.org