TEMPO-oxidized cellulose fibers from wheat straw: Effect of ultrasonic pretreatment and concentration on structure and rheological properties of suspensions

Ruijing Qu; Mengxue Tang; Yong Wang; Dong Li; Lijun Wang

doi:10.1016/j.carbpol.2020.117386

TEMPO-oxidized cellulose fibers from wheat straw: Effect of ultrasonic pretreatment and concentration on structure and rheological properties of suspensions

Carbohydr Polym. 2021 Mar 1:255:117386. doi: 10.1016/j.carbpol.2020.117386. Epub 2020 Nov 7.

Authors

Ruijing Qu¹, Mengxue Tang¹, Yong Wang², Dong Li³, Lijun Wang⁴

Affiliations

¹ College of Food Science and Nutritional Engineering, Beijing Key Laboratory of Functional Food from Plant Resources, China Agricultural University, Beijing, 100083, China.
² School of Chemical Engineering, UNSW, Sydney, NSW, 2052, Australia.
³ Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Engineering, National Energy R & D Center for Non-food Biomass, China Agricultural University, Beijing, 100083, China.
⁴ College of Food Science and Nutritional Engineering, Beijing Key Laboratory of Functional Food from Plant Resources, China Agricultural University, Beijing, 100083, China. Electronic address: wlj@cau.edu.cn.

PMID: 33436215
DOI: 10.1016/j.carbpol.2020.117386

Abstract

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.

Keywords: 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO); Carboxylated cellulose; Lissajous curves; Rheological properties; Sodium bromide; Sodium chlorite; Sodium hydroxide; Sodium hypochlorite; Sol-gel transition; Ultrasonic.