Abstract:Sugarcane bagasse cellulose（SBC）was extracted from the waste bagasse from sugarcane sugar production and carboxylated to produce sugarcane bagasse cellulose nanofibers（SBCNFs）.The structural properties and rheological behavior of SBCNFs were then examined. The results of Zeta potential detection showed that the surface of SBCNFs was negatively charged,and transmission electron microscopy（TEM）showed that the SBCNFs were filamentous with diameters of 3-10 nm and lengths of 1 000-2 000 nm. The results of Fourier transform infrared spectroscopy（FTIR）and X-ray diffraction（XRD）showed that the carboxylation pretreatment successfully attached carboxyl groups on the surface of SBCNFs,in which carboxylate radicals existed in the form of carboxylates. Compared with that of SBC,the crystalline structure of SBCNFs did not change and remained the same as that of cellulose I,while the crystallinity index changed from 32.62% to 71.37%.The results of thermogravimetric（TG）analysis showed that SBCNFs had higher thermal stability than SBC. The results of the rheological test showed that the viscosity and shear-thinning behavior of the SBCNFs suspension enhanced with the increase in the suspension concentration.In the linear viscoelastic region（stress<10%）,where the energy storage modulus（G′）was larger than the loss modulus（G″）with the elastic behavior being dominant,the suspension of SBCNFs exhibited solid-state properties and great thixotropic recovery. In conclusion,the prepared SBCNFs had a fibrous structure and excellent properties.