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Conventional polyimide nanocomposites reinforced with graphene-based nanofillers usually possess excellent properties, such as high thermal decomposition temperature, enhanced tensile strength, tensile modulus, etc. However, the elongation at break of the nanocomposites is reduced. Here, we prepared N-doped graphene quantum dots/colorless polyimide nanocomposite (N-GQDs/CPI) films for the first time by in-situ polymerization, whose elongation at break is about 2 times that of the pure film. Meanwhile, the thermal properties and other mechanical properties of the films are improved. Through analyzing FT-IR, XPS, XRD, TAG SEM, etc. of N-GQDs and the films, we consider that the strengthening mechanism of matrix performance is attributed to N-GQDs' well dispersion, its small size effects and strong interface interaction with the matrix. Furthermore, at the indicative wavelength of 550 nm, the optical transmittance of the film with 1 wt% N-GQDs still maintains 79%, indicating the resulting films have excellent optical transmittance. The hydrophilic properties of the prepared films' surface is reduced, their water surface contact angle are increased from 63 ± 2.7° to 92 ± 1.7° with the content of N-GQDs increasing. This research shows that N-GQDs can enhance the various properties of polyimide and provides a high performance nanocomposite films for potential flexible substrates. [ABSTRACT FROM AUTHOR]

In this study, modified wollastonite nanorods (MWNRs) as core and polystyrene (PS) as a shell [Core-shell nanorods (CSNRs)] was synthesized using atomized microemulsion technique. CSNRs were compounded with styrene butadiene rubber (SBR) on a two-roll mill and compressed into sheet form using compression moulding machine. The encapsulation of MWNRs into PS was confirmed by field emission scanning electron microscope (FE-SEM), transmission electron microscope, X-ray diffraction spectrophotometer (XRD) and Fourier transform infrared spectroscopy. CSNRs/SBR nanocomposites were also characterized by XRD, FE-SEM, differential scanning calorimetry, thermogravimetric analysis, universal testing machine and Mooney viscometer. Incorporation of CSNRs resulted in improvement in rheological, thermal and mechanical properties of the nanocomposites. FE-SEM images showed a perfect dispersion of the CSNRs in SBR matrix at <1 wt% loading. Thermal stability of CSNRs/SBR nanocomposites was also increased significantly by the addition of CSNRs. Graphical abstract: [ABSTRACT FROM AUTHOR]