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The incompatible thermoplastic poly lactic acid/carboxylated acrylonitrile butadiene rubber (PLA/XNBR) was prepared, and the effect of graphene oxide (GO) as a reinforcement and glycidyl methacrylate (GMA)-grafted XNBR (XNBR-g-GMA) as a compatibilizer on the properties of PLA/XNBR blend was investigated in this research. The microstructure, mechanical behavior, thermal, rheology, and dynamic mechanical properties of PLA/XNBR composites were investigated by field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), differential scanning calorimetry (DSC), tensile test, and dynamic mechanical thermal analysis (DMTA). The incorporation of XNBR-g-GMA improved the compatibility of the PLA/XNBR blend phases, as confirmed by microstructure and DMTA analysis. The results of the mechanical properties showed that with an increase in GO content in the PLA/XNBR/XNBR-g-GMA matrix, there was a significant improvement in tensile strength, Young's modulus, hardness, and impact strength. In order to validate the experimental mechanical and rheological results, various theoretical models were applied and a good agreement was observed between the theoretical and experimental data. [ABSTRACT FROM AUTHOR]

In this research, nanocomposites based on carboxylated nitrile rubber (XNBR)/natural rubber (NR) with different concentrations of graphene oxide (GO) were prepared by melt mixing method. The role of XNBR-grafted maleic anhydride (XNBR-g-GMA) as a compatibilizer and the effect of GO content on the morphological, mechanical, rheological, and vulcanization properties were evaluated. It was observed that with increasing the concentration of GO, the scorch and vulcanization time decreased, while the torque of the samples increased. Morphological studies illustrated that by raising the concentration of GO in the presence of a compatibilizer, the fracture surface of nanocomposites became rougher and the average size of dispersed phase decreased. In addition, the presence of XNBR-g-GMA compatibilizer improved the uniform dispersion of GO within the XNBR/XNBR-g-GMA/NR matrix. The mechanical properties of nanocomposites showed the best results for XNBR/NR with a ratio of 75/25. Theoretical studies on the mechanical and rheological properties of nanocomposites performed by Mori-Tanaka and Carreau-Yasuda models and illustrated a good agreement with experimental data. [ABSTRACT FROM AUTHOR]

In this study, a series of elastomeric nanocomposites based on specific amounts of polyamide6 (PA6)/chloroprene rubber (CR) blends which are compatibilized with ethylene propylene diene monomer‐grafted‐maleic anhydride (EPDM‐g‐MA) and different amounts of graphene oxide (GO) were prepared with melt mixing method. The effect of compatibilizer and reinforcement concentration in the PA6/CR blend matrix was investigated using theoretical and experimental analysis. Dispersion of nanoplatelets within rubber blend matrix was proven with transmission electron microscopy and field emission‐scanning electron microscopy. The modified microstructure of samples showed the significant effect of EPDM‐g‐MA and GO on the size reduction of CR droplets in the PA6 continuous phase. The results from differential scanning calorimetry and dynamic mechanical thermal analysis revealed the effect of EPDM‐g‐MA and GO as an effective nucleating agent in PA6‐enriched GO/CR (PA6EGO/CR). The findings obtained from thermogravimetric analysis displayed that the GO in the presence of an EPDM‐g‐MA as a compatibilizer can cause a higher thermal stability in PA6EGO/CR. From mechanical properties, by adding a compatibilizer to the PA6/CR blend, the tensile strength changed from 39.0 to 45.1, the Young's modulus altered from 522.2 to 716.0 and the elongation at break changed from 246.8 to 222.2. While incorporation of 5 phr of GO to the compatibilized blend, the tensile strength increased by 25.2%, the Young's modulus increased by 36.6% and the elongation at break decreased by 20%. The Christensen–Lo model used for analyzing the stiffness of PA6EGO/EPDM‐g‐MA/CR with emphasis on the influence of the interphase region to predict the effect of various loadings of GO and EPDM‐g‐MA of Young's modulus. The rheology and creep tests showed a significant effect of EPDM‐g‐MA and GO content on the rheology behavior of nanocomposites. [ABSTRACT FROM AUTHOR]