Structures and cyclization behaviors of gel-spun cellulose/polyacrylonitrile composite fibers. (January 2020)

• Record Type: Journal Article
• Authors: Cao, Zhuo; Li, Weijie; Suo, Xidong; Liu, Yaodong; Lu, Chunxiang
• Is Part Of: Polymer testing. Volume 81(2020)
• Publication Date: 2020-01
• Subjects: Cellulose -- Polyacrylonitrile -- Gel spinning -- Composite fiber -- Cyclization; Polymers -- Testing -- Periodicals; Polymères -- Tests -- Périodiques; 620.1920287
• DOI: 10.1016/j.polymertesting.2019.106276
• Languages: English
• ISSNs: 0142-9418

Abstract

Abstract: Polyacrylonitrile (PAN)/cellulose composite fibers have been produced by dry-jet gel spinning through their co-solution. The rheological properties of PAN/cellulose/dimethylacetamide/LiCl solutions containing different cellulose contents from 0 to 10 wt% were characterized, and 5 wt% PAN/cellulose composite solution shows the best solution homogeneity. During gel spinning, the cellulose forms elongated particles inside the gelation bath, and the particle diameters depend on the as-spun draw ratio. It was found that the glass transition of PAN fibers shifts to higher temperatures along with the increase of cellulose content, and the glass transition activation energy of PAN chains becomes higher when cellulose particles become smaller. Regardless the changes of cellulose amount (2–10 wt%) and particle diameter (7.1–1.4 μm), the cyclization activation energy of PAN/cellulose composite fibers is 13–17% lower than that of neat PAN fibers. Our experiments suggest that the addition of cellulose in PAN fibers has no direct effect on the cyclization reaction of PAN chains. Instead, the released by-products during the pyrolysis of cellulose at high temperature degradation affect the cyclization reaction of PAN chains. Highlights: Polyacrylonitrile (PAN)/cellulose composite fibers were produced by dry-jet gel spinning. The addition of cellulose leads to 13–17% decrease of the cyclization activation energy of PAN chains. The PAN cyclization is affected by the pyrolysis by-products of cellulose. The cellulose contents and diameters do not affect the PAN cyclization reaction.