Formation and phase transition of the disordered Form I' in electrospun PEO-thiourea complex nanofibers. (20th January 2021)

• Record Type: Journal Article
• Authors: Zou, Shufen; Xie, Yousen; Lv, Ruihua; Na, Bing; Tong, Zaizai; Liu, Hesheng
• Is Part Of: Polymer. Volume 213(2021)
• Publication Date: 2021-01-20
• Subjects: Poly (ethylene oxide) -- Thiourea -- Complex -- Electrospinning -- Disordered Form I′; Polymers -- Periodicals; Polymerization -- Periodicals; Polymères -- Périodiques; Polymérisation -- Périodiques; 547.7
• DOI: 10.1016/j.polymer.2020.123303
• Languages: English
• ISSNs: 0032-3861

Abstract

Abstract: A new crystal modification named as Form I′, a disordered counterpart of Form I, was for the first confirmed for the PEO (Poly (ethylene oxide))-thiourea complex nanofibers prepared by electrospinning technique. The Form I′ has the same thiourea molar fraction (0.4) as the Form I, but is more disordered and less thermally stable. During the heating process, an unexpected cold crystallization peak around 93.0 °C was observed for the Form I′ in the DSC heating scan. It arises from the phase transition from Form I′ to Form I. Temperature-dependent FTIR demonstrates that the Form I' to Form I phase transformation undergoes a sequential process during the heating period. Graphical abstract: Image 1 Highlights: A disordered PEO-thiourea complex (Form I′) was produced by electrospinning. Cold crystallization was observed for the Form I′ in the DSC heating scan. Phase transition from Form I′ to Form I occurred during cold crystallization.