Influence of the molecular weight on mechanical behavior and associated strain-induced structural evolution of Poly(ethylene 2,5-furandicarboxylate) upon biaxial stretching

A Step Forward in Thermoplastic Polyesters: Understanding the Crystallization and Melting of Biobased Poly(ethylene 2,5-furandicarboxylate) (PEF)

“…The macroscopic properties of a polymeric specimen are the result of the chemical structure and characteristics such as chain stiffness or flexibility, symmetry, polarity, and intermolecular forces, the physical properties such as crystallization ability, crystallization rates, and density of the material, and the type and conditions of processing . In contrast to the crystallization of PET, which has been studied extensively, the crystallization of PEF was the subject of only a few papers up to now. − Usually, the isothermal crystallization of polymers is studied, as it is crucial from a theoretical standpoint. However, the crystallization of industrial polymers during processing is in principle dynamically non-isothermal.…”

Structural Evolutions of Initially Amorphous Polymers during Near‐Tg Stretching: A Minireview of Recent Progresses

“…The multistage evolution process of SIC with evidence of intermediate phase induced by stretching has also been found in case of aromatic counterparts of PET, for instance, traditionally in poly(ethylene naphthalate) (PEN) [ 14,82–86 ] and more recently in poly(pentamethylene 2,6‐naphthalate) (PPN), [ 87 ] poly(ethylene furanoate) (PEF), [ 88–90 ] and poly(trimethylene terephthalate) (PTT). [ 91 ] This common behavior is very likely to be originated from the laterally ordered packing of aromatic rings through π – π interactions in early stage of stretching.…”

“…Recently, it has been reported that macromolecular orientation has a restricting effect on the formation of crazes, which allows the activation of shear bands as the more favorable deformation mechanism. [ 90 ] Note that the transition of deformation mechanism may be closely linked to the geometric condensation of chain network, as formerly discussed in case of PS (Section 2.2).…”

“…This polymer undergoes brittle failure upon uniaxial stretching, but is able to exhibit a remarkable improvement of strain at break (over 150%) when being pre‐stretched at suitable conditions (Table 1). [ 90,101 ] From a view of microstructure evolution, this brittle‐to‐ductile transition identified in case of PEF should be related to a change of elementary deformation mechanisms from crazing to shear bands. [ 90 ] In addition to mechanical response, having a pre‐stretching history can also improve the gas barrier properties of PEF.…”

“…[ 90,101 ] From a view of microstructure evolution, this brittle‐to‐ductile transition identified in case of PEF should be related to a change of elementary deformation mechanisms from crazing to shear bands. [ 90 ] In addition to mechanical response, having a pre‐stretching history can also improve the gas barrier properties of PEF. Nevertheless, the decrease of gas permeability is less significant compared to the case of PET, [ 101 ] which might be related to the low crystallinity obtained in the former.…”