Poly(vinylidene fluoride)/cellulose nanocrystals composites: rheological, hydrophilicity, thermal and mechanical properties

Cellulose nanocrystals (CNCs) were used to improve the performance of poly(vinylidene fluoride) (PVDF), and the composite properties were characterized. The results showed that the prepared nanocomposites displayed the increases in mechanical properties. In particular, with the incorporation of 6 wt% CNCs, increases in tensile strength and dynamic storage modulus were observed. For hydrophilicity, the water contact angle decreased from 90° to 77° with the incorporation of only 3 wt% CNCs, indicating improved hydrophilicity. Addition of CNCs to PVDF also helped improve its thermal stability and crystallinity. It was suggested that CNCs played a nucleating role in the crystallization of PVDF, which was supported by the smaller size of PVDF spherulite observed from scanning electron microscopy analysis. Rheological results indicated that incorporation of CNCs also increased both melt storage modulus and shear viscosity of composites. Overall, our present work demonstrates that CNCs can provide PVDF with simultaneously improved properties.