Evidence of Cooperative Rearranging Region size anisotropy for drawn PET

In this work, we determined the Cooperative Rearranging Region (CRR) average sizes at the glass transition temperature according to Donth’s approach. From Temperature Modulated Differential Scanning Calorimetry (TMDSC) and Dynamical Mechanical Analysis (DMA) investigations, the CRR average size has been estimated for drawn poly(ethylene terephthalate) (PET) with various draw ratios ranging from λ = 1 to λ = 4. We show that the CRR size becomes anisotropic as a function of a specific molecular orientation induced by drawing effect.