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A reactive extrusion process was developed to fabricate polymer/graphene nanocomposites with good dispersion of graphene sheets in the polymer matrix. The functionalized graphene nanosheet (f-GNS) activated by diphenylmethane diisocyanate was incorporated in thermoplastic polyester elastomer (TPEE) by reactive extrusion process to produce the TPEE/f-GNS masterbatch. And then, the TPEE/f-GNS nanocomposites in different ratios were prepared by masterbatchbased melt blending. The structure and morphology of functionalized graphene were characterized by Fourier transform infrared, X-ray photoelectron spectroscopy, X-ray diffraction and transmission electron microscopy (TEM). The incorporation of f-GNS significantly improved the mechanical, thermal and crystallization properties of TPEE. With the incorporation of only 0.1 wt% f-GNS, the tensile strength and elongation at break of nanocomposites were increased by 47.6% and 30.8%, respectively, compared with those of pristine TPEE. Moreover, the degradation temperature for 10 wt% mass loss, storage modulus at À70°C and crystallization peak temperature (T cp ) of TPEE nanocomposites were consistently improved by 17°C, 7.5% and 36°C. The remarkable reinforcements in mechanical and thermal properties were attributed to the homogeneous dispersion and strong interfacial adhesion of f-GNS in the TPEE matrix. The functionalization of graphene was beneficial to the improvement of mechanical properties because of the relatively well dispersion of graphene sheets in TPEE matrix, as suggested in the TEM images. This simple and effective approach consisting of chemical functionalization of graphene, reactive extrusion and masterbatch-based melt blending process is believed to offer possibilities for broadening the graphene applications in the field of polymer processing.

A series of nanocomposites based on cellulose nanocrystals (CNCs) and epoxy acrylate resin (EA) were prepared using solution casting followed by UV curing. The microstructure of the CNCs and nanocomposites were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The thermal behavior and dynamic mechanical properties of the nanocomposites were determined using dynamical mechanical analysis (DMA) and thermogravimetric analysis (TGA). The transparency of the nanocomposite films was examined by UV–vis transmission spectroscopy. TGA results showed that the thermal stability of EA was affected slightly after incorporation of CNCs. The results from DMA showed that the storage modulus of nanocomposites improved over the entire temperature range compared to pure EA derived from the reinforcing effect of the CNCs. The glass transition temperature of nanocomposites was increased with the increase of CNC loading levels. The ultraviolet–visible spectra of the films showed no obvious absorbance over a range of 400–800 nm, which revealed that the films were transparent.

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