Cellulose nanocrystals were successfully isolated from cloth hairs using phosphoric acid. The

yields, degree of polymerization, morphology, average particle size, crystallinity, chemical structure, and thermal stability of the prepared nanocrystals were investigated. The results demonstrated that yields and degree of polymerization decreased with the increase

of concentration of phosphoric acid due to preferential degradation of amorphous cellulose, resulting in high thermal stability and crystallinity. Morphological analysis revealed that hydrolysis was more homogeneous with increasing acid concentration. In comparison with the cellulose nanocrystals prepared with 6.5, 8.0, and 9.5 M H3PO4, those prepared with 11.0 M

H3PO4 had the most uniform particle sizes. Moreover, the nanocrystals had important influence on the crystallization of semicrystalline polymer.