Extensional rheology of cellulose/NaOH/urea/H₂O solutions

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• 作者：Fei Lu ; Chao Zhang ; Hongliang Kang ; Yong Huang ; Ruigang Liu
• 关键词：Cellulose ; Solution ; NaOH/urea/H2O ; Extensional rheology
• 刊名：Cellulose
• 出版年：2016
• 出版时间：October 2016
• 年：2016
• 卷：23
• 期：5
• 页码：2877-2885
• 全文大小：857 KB
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Chemistry
  Bioorganic Chemistry
  Physical Chemistry
  Organic Chemistry
  Polymer Sciences
  
• 出版者：Springer Netherlands
• ISSN：1572-882X
• 卷排序：23

文摘

The extensional flow behaviors of cellulose/NaOH/urea/H₂O solution were investigated by using capillary breakup extensional rheometry (CaBER). The effects of temperature, storage time and cellulose concentrations on both the storage modulus G′ and the loss modulus G″ were also analyzed. For 2 wt% cellulose solution, the G′, G″ and filament lifetime remained unchanged after long storage time. While, for 4 wt% cellulose solution, physical gels could form at either higher temperature or for longer storage time, and the filament lifetime, the relaxation time (λ_e) and the initial extensional viscosity (η_e0) first increased and then decreased with increase of the storage time. The transition points of the filament lifetime shifted to lower storage time with the increase of the temperature. The η_e0 is proportional to λ_e. The results presented suggest that the extensional properties of the cellulose/NaOH/urea/H₂O solution first increase and then decrease during the gelation process, and the spinning time, which decreases linearly with the increase in the storage temperature, must be controlled below the time that η_e0 starts to decrease.