“…Therefore, the deformation instabilities often appear to be a very important part of the deformation process, facilitating easier strain accommodation. The major deformation instabilities observed in semicrystalline polymers are associated with cavitation (see, e.g., the review [ 14 ]), the microbuckling of lamellae [ 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 ], and their fragmentation due to slip localization [ 6 , 20 , 21 , 23 , 24 ]. Such instabilities often lead to profound structural and morphological changes, such as conversion of the initial lamellar/spherulitic morphology into microfibrillar morphology, usually observed in tension.…”