Synthesis, characterization and viscoelastic properties of nanocrystalline cellulose grafted with poly(N-isopropylacrylamide)

Nanocrystalline cellulose (NCC) was grafted with the thermo-responsive polymer poly(N-isopropylacrylamide) (Nipaam) via living radical polymerization. Various techniques were used to characterize the physical, chemical, morphological and thermal properties of the resulting material. The viscoelastic properties and the stability of the functionalized NCC were compared to the unmodified NCC using rheometry. The shear viscosity of the NCC suspension decreased slightly with an increase in temperature from 20\ub0C to 45\ub0C, indicating a stable system. The storage modulus and shear viscosity values both exhibited a burst increase at about 32.5\ub0C, which is assigned to be the lower critical solution temperature (LCST) of poly(Nipaam). This indicates the successful functionalization of Nipaam polymer chains on NCC. In addition, the thermodynamic property of poly(Nipaam) also prevailed on the grafted NCC.Peer reviewed: YesNRC publication: Ye