On the strain-induced structural evolution of Poly(ethylene-2, 5-furanoate) upon uniaxial stretching: An in-situ SAXS-WAXS study. (3rd January 2018)

• Record Type: Journal Article
• Authors: Stoclet, G.; Lefebvre, J.M.; Yeniad, B.; Gobius du Sart, G.; de Vos, S.
• Is Part Of: Polymer. Volume 134(2017)
• Page Start: 227
• Page End: 241
• Publication Date: 2018-01-03
• Subjects: PEF -- Biobased polyester -- Crystallization -- Poly(ethylene-2, 5-furanoate) -- Structural characterization; Polymers -- Periodicals; Polymerization -- Periodicals; Polymères -- Périodiques; Polymérisation -- Périodiques; 547.7
• DOI: 10.1016/j.polymer.2017.11.071
• Languages: English
• ISSNs: 0032-3861

Abstract

Abstract: Among "green" alternatives for oil-based commodity plastics like Polyethylene, Polyamides, and Poly(Ethylene Terephthalate) (PET), a new class of polyesters synthesized from furanedicarboxylic acids (FDCAs) is currently in the spotlight of both the academic and industrial communities. Of particular interest is Poly(Ethylene-2, 5-Furanoate) (PEF), which can be synthesized from biobased monomers. Owing to its physical properties, PEF qualifies as a strong candidate for PET substitution particularly in bottle, fiber and film packaging applications. In the present study the structural evolution of PEF upon uniaxial stretching has been investigated by means of in-situ Wide Angle and Small Angle X-ray Scattering experiments. At room temperature, initially un-oriented amorphous PEF exhibits brittle behavior in relation to its ability to deform by crazing. The mechanical behavior of PEF as a function of temperature is quite similar to the one observed in the case of oil-based aromatic polyesters like PET or Poly(Ethylene Naphtalate) (PEN). However, the processing range where a strain-hardening phenomenon occurs, caused by strain-induced crystallization is clearly more narrow in PEF. As a main result of this work, characterization of the structure induced upon stretching PEF provided evidence for the formation of a mesomorphic phase at low stretching temperatures. This transient phase is characterized by the presence of a meridional diffraction peak at low Bragg Angles. Under appropriate drawing conditions, strain-induced crystallization occurs, although quantitatively to a lesser extent than is established for PET. Examination of the crystalline structure of this strain-induced phase revealed that it differs from the thermally induced one. This has been ascribed to the fact that the macromolecules crystallize in an extended conformation upon drawing. Graphical abstract: Image 1 Highlights: The structural evolution of Poly(ethylene 2, 5 Furanoate) upon uniaxial stretching is analyzed. A mesomorphic structure is induce for stretching temperatures near from the glass transition. The mesomorphic structure is characterized by an intramolecular order. Thermally and mechanically induced crystalline structures are different.