TEMPO-oxidized cellulose fibers from wheat straw: Effect of ultrasonic pretreatment and concentration on structure and rheological properties of suspensions
TEMPO-oxidized cellulose fibers from wheat straw: Effect of ultrasonic pretreatment and concentration on structure and rheological properties of suspensions
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麦秆中的 TEMPO 氧化纤维素纤维：超声波预处理和浓缩对悬浮液结构和流变性能的影响
DOI：
10.1016/j.carbpol.2020.117386
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发表时间：
2021-01-09
影响因子：
11.2
通讯作者：
Wang, Lijun
中科院分区：
文献类型：
--
作者：
Qu, Ruijing;Tang, Mengxue;Wang, Lijun
以麦草为原料，采用超声波和化学处理法制备了纤维素和氧化纤维素纤维(TOCF)，并对其结构和功能进行了研究。用流变学方法研究了TOCF悬浮液的溶胶-凝胶转变过程，揭示了不同浓度下超声波预处理和温度的作用。结果表明，经超声处理和未经超声处理的TOCF在FTIR中具有相似的官能团。然而，X射线衍射仪和热重分析仪分别显示了不同的晶体结构和热稳定性。凝胶的形成与超声前处理无关，而TOCF悬浮液的浓度和温度对其流变性有很大的影响。TOCF悬浮液在大振幅振荡剪切试验中表现出应变变稀行为。Lissajous曲线表明，纤维浓度和应变幅值对弹塑性行为的影响较大，而超声波处理对弹塑性行为的影响不明显。这些结果有助于加深对TOCF结构与流变性能之间关系的理解。
Cellulose and TEMPO-oxidized cellulose fibers (TOCF) from the wheat straw were prepared with ultrasonic and chemical treatments to investigate structure and functionalities. Sol-gel transition of TOCF suspensions has been investigated using rheology to unveil the roles of ultrasonic pretreatment and temperature at various concentration. It was found that TOCF extracted with or without ultrasonic pretreatment exhibit similar functional groups in FTIR. However, different crystal structures and thermal stabilities were revealed in XRD and TGA, respectively. The gelation was independent of the ultrasonic pretreatment, while the rheological properties were highly infuenced by the concentration and temperature of the TOCF suspensions. TOCF suspensions presented a strain thinning behavior in large amplitude oscillatory shear tests. Lissajous curves showed that the elastoplastic behavior was predominantly modulated by the fiber concentration and strain amplitude other than the ultrasonic pretreatment. These results could improve the understanding of the relationships between TOCF structure and rheological properties.