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Polymer composite are very interesting materials in automotive industry. Nanocomposites play a crucial role in the automotive parts and cars weight reduction fields. Hybridization of polymer nanocomposites is appeared as a process of choice in obtaining the required property/weight ration. Simple and hybrid nanocomposites of polypropylene (PP) blend with carbon nanotubes (CNTs) having different aspect ratios and nanosilica at different nanosilica contents were prepared in molten state in an internal mixer. Scanning electron microscopic images along with rheological and tensile properties revealed that only 0.2 wt% CNT is high enough to finely disperse nanosilica particles in PP matrix in the absence of any chemical compatibilizer. Differential scanning calorimetric thermograms showed that none of nanoparticles has any effect on crystallinity of PP. Mechanical characterizations showed that hybrid composites are superior to PP‐S3 composite. Due to its more intensive hydrodynamic motions it was also observed that the longer CNT showed a higher ability to disintegrate nanosilica particles aggregates. Transmission electron microscopic images well portrayed the nanosilica particles in the vicinity of CNTs' surfaces which accounts for electrostatic adsorption of fine nanosilica particles. At such a low CNT content (say 0.2 wt%) in the absence of any chemical compatibilizer, elongation at break of the tensiled nanocomposites raised from 13.23% to 35.41% and fracture energy was mounted from 1253 to 2750 J. This divulges the effectiveness of CNTs to disperse nanosilica in PP matrix but a poor adhesion between the particles and PP matrix is an overwhelming drawback yet. Under these conditions a maleic anhydride grafted PP (PP‐g‐MA) was added to the composite in molten state. The tensile strength of these chemically compatibilized nanocomposites increased with respect of that of their counterpart physically mixed nanocomposites. For example, in the presence of this chemical compatibilizer, the tensile strength of PP‐S3 nanocomposite raised from 21 to 28 MPa. [ABSTRACT FROM AUTHOR]

Anticipating dynamic mechanical behavior of polymeric materials over long period of time and under different frequencies is the first step to be taken to afford load‐bearing applications. Nevertheless, what we know about dynamic mechanical behavior of polymers is only limited to experiments, which necessitates large pools of data spending too much money, time, and energy. Environmentally‐friendly inorganic tungsten disulfide nanotube (INT‐WS2), was introduced to polypropylene/ethylene vinyl acetate copolymer (PP/EVA, 75/25 wt/wt) blends through melt mixing, and dynamic mechanical analysis (DMA) frequency sweep tests were performed to obtain master curves based on time‐temperature superposition (TTS) theorem. The influence of EVA phase change (solid, semi solid, and melt domains) on the creep and recovery behavior of nanocomposites in linear region was then studied. It was found that using INT‐WS2 along with PP‐g‐MA results in distinctive improvement in creep‐recovery response of nanocomposites. Burger and Weibull models were used to mimic viscoelastic behavior of the nanocomposites. Creep compliance master curves predicted creep compliance, while analysis of cyclic creep‐recovery at 30 °C revealed almost constant permanent strain parameters for sample having 5 wt% INT‐WS2 and PP‐g‐MA after three times repeating test cycles. Influence of phase change phenomenon of EVA domains on creep‐recovery behavior of nanocomposites was mechanistically demonstrated. POLYM. COMPOS., 40:1964–1978, 2019. © 2018 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

Anticipating dynamic mechanical behavior of polymeric materials over long period of time and under different frequencies is the first step to be taken to afford load‐bearing applications. Nevertheless, what we know about dynamic mechanical behavior of polymers is only limited to experiments, which necessitates large pools of data spending too much money, time, and energy. Environmentally‐friendly inorganic tungsten disulfide nanotube (INT‐WS2), was introduced to polypropylene/ethylene vinyl acetate copolymer (PP/EVA, 75/25 wt/wt) blends through melt mixing, and dynamic mechanical analysis (DMA) frequency sweep tests were performed to obtain master curves based on time‐temperature superposition (TTS) theorem. The influence of EVA phase change (solid, semi solid, and melt domains) on the creep and recovery behavior of nanocomposites in linear region was then studied. It was found that using INT‐WS2 along with PP‐g‐MA results in distinctive improvement in creep‐recovery response of nanocomposites. Burger and Weibull models were used to mimic viscoelastic behavior of the nanocomposites. Creep compliance master curves predicted creep compliance, while analysis of cyclic creep‐recovery at 30 °C revealed almost constant permanent strain parameters for sample having 5 wt% INT‐WS2 and PP‐g‐MA after three times repeating test cycles. Influence of phase change phenomenon of EVA domains on creep‐recovery behavior of nanocomposites was mechanistically demonstrated. POLYM. COMPOS., 40:1964–1978, 2019. © 2018 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

The principles of large deformation rubber viscoelasticity are not new, but there is a need to make explicit certain theories or modify the available models for deeper understanding of behavior of rubber nanocomposites. The difficulties are chiefly due to the assumptions under which a given theoretical model fails to predict large deformation behavior of elastomer nanocomposites, as models are basically proposed for neat rubbers, and more critically they can hardly be supposed to remain valid for systems in which two or more nanofillers having different nature, shape, and size are used. This work attempts to apply nonlinear hyperelastic theoretical models proposed for hyperelastic behavior of rubbers for nanocomposites containing multi‐walled carbon nanotubes (MWCNTs) and graphene nanoplatelets (GnPs), and to explore the interplay between morphology, viscoelastic properties, and large deformation behavior of typical hydrogenated acrylonitrile butadiene rubber (HNBR)‐based rubber nanocomposites. Morphological observations used for knowing the localization of nanofillers, where dynamic mechanical and uniaxial tensile strength analyses exhibited a rise in both Young's modulus and tensile strength of composites by MWCNTs and GNPs content up to 200 and 160%, respectively. We applied Arruda‐Boyce model and appropriately predicted nonlinear hyperelastic behavior of HNBR model nanocomposites and interfacial interactions between phases, as recognized by comparing model parameters for nanocomposites containing only MWCNTs, or only GNPs, and their combinations varying filler content. POLYM. COMPOS., 40:E1548–E1558, 2019. © 2018 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]