Composites and nanocomposites
Maziyar Sabet
Abstract
Polypropylene (PP), a widely used polyolefin, suffers from poor electrical conductivity, which limits its use in electronic packaging and electromagnetic interference (EMI) shielding. In this study, conductive and EMI-shielding PP nanocomposites were fabricated using dual-functionalized carbon nanotubes ...
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Polypropylene (PP), a widely used polyolefin, suffers from poor electrical conductivity, which limits its use in electronic packaging and electromagnetic interference (EMI) shielding. In this study, conductive and EMI-shielding PP nanocomposites were fabricated using dual-functionalized carbon nanotubes (CNTs) via a solvent-free melt-blending route. Sequential acid and silane treatments improved CNT dispersion and interfacial compatibility, yielding a low percolation threshold of ~0.3 wt.% and an electrical conductivity of 1.2 × 10⁻² S/m at 3 wt.% CNT. At 5 wt.%, the EMI shielding effectiveness exceeded 41.5 dB, with more than 80% of the attenuation arising from absorption, as confirmed by S-parameter analysis. AI-assisted image segmentation (U-Net architecture) quantified an ~80% reduction in CNT agglomeration and increased interparticle spacing, correlating with the enhanced electrical, dielectric, and thermal properties. The dielectric constant increased from ~2.3 in neat PP to ~6.0 at 5 wt.% CNT with low dielectric loss (tan δ < 0.02), while thermal conductivity improved by ~75%. Tensile strength and modulus increased up to 3 wt.% CNT with a moderate loss in ductility. The combination of dual CNT functionalization, scalable melt processing, and AI-based dispersion quantification provides a reproducible approach for designing lightweight, conductive, and EMI-shielding polyolefin nanocomposites for electronic, automotive, and aerospace applications.
Simulation & Modeling
Utkarsh A. Patil; Pravin Ramchandra Kubade
Abstract
The growing need for enhanced materials has led to the development of nanocomposites, which have shown great potential in various industries. However, optimizing the composition of these materials to achieve the best mechanical performance and cos t-effectiveness remains a challenge. This research addresses ...
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The growing need for enhanced materials has led to the development of nanocomposites, which have shown great potential in various industries. However, optimizing the composition of these materials to achieve the best mechanical performance and cos t-effectiveness remains a challenge. This research addresses this challenge by employing a virtual experimental approach, utilizing Digimat for material modeling and CATIA for design and finite element analysis (FEA). This approach allows for the simulation and analysis of different nanocomposite compositions without the need for costly and time-consuming physical experiments. The study focuses on Polypropylene (PP) and polyvinyl chloride (PVC) based nanocomposites with graphene and carbon black reinforcements. The research investigates the impact of varying the weight percentages of these nanofillers on the mechanical properties of the composites. The PP/PVC blends are created in different weight ratios to provide further compositional control. The material preparation is carried out in Digimat, where the properties of the composites are defined using a micromechanical model. The FEA is then conducted in CATIA, where a standard AS TM D638 tensile specimen is simulated under controlled conditions. The results are validated by varying mesh sizes to optimize deflection and Von Mises s tress predictions. Furthermore, an economic analysis is conducted to evaluate the cos t-effectiveness of the different nanocomposite compositions. The study highlights the importance of virtual experimentation in materials science, as it allows for efficient exploration of various material compositions and reduces the need for physical prototyping. This approach accelerates the material development process and enables the optimization of material design for specific applications. The virtual trials explored alternatives to PVC using PP-based composites reinforced with graphene/carbon black. PP/PVC 40/60 reinforced with 1.5% wt. graphene (P4V6G15) and reinforced with 7.5% wt. carbon black (P4V6C75) showed 31.6% and 31.2% deflection reductions compared to pure PP, respectively. These results show that P4V6 blends, especially those with graphene or high carbon black concentrations, serve as promising alternatives to conventional PVC. Among them, P4V6C75 stands out by offering the best overall mechanical performance. It also provides the lowest production cos t. In terms of economic favorability, P4V6C75 is approximately 2.55 times more cos t-effective than the graphene-based blend P4V6G15. This combination of high performance and low cos t makes P4V6C75 the most suitable candidate for PVC replacement.
Monica Tanniru; Pankaj Tambe
Abstract
The automotive industry has a significant need for composites made of high impact strength polymer blends. Melt-mixing was used in this work to reinforce hollow glass microspheres (HGMs) with 50:50 polypropylene/ polyamide 6 (PP/PA6) blends. Using FTIR spectroscopy, it is observed that the 50PP50PA6 ...
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The automotive industry has a significant need for composites made of high impact strength polymer blends. Melt-mixing was used in this work to reinforce hollow glass microspheres (HGMs) with 50:50 polypropylene/ polyamide 6 (PP/PA6) blends. Using FTIR spectroscopy, it is observed that the 50PP50PA6 blend is compatibilized with maleated PP, producing a reactively compatible blend. The compatibilization process has refined the morphology of the 50PP50PA6 blend. Additionally, the incorporation of HGMs into the 50PP50PA6 blend produced a finer blend morphology, which helped to enhance the crystallinity of the polymer phase and mechanical properties to the maximum. The tensile modulus and impact strength of a 50PP50PA6 blend with maleated PP that contains 3 wt.% HGMs are better than those of a neat blend by 15.6% and 90.1%, respectively. Fractography was used to identify the fracture mechanism which reveals the retention of droplets over the surface of impact specimens of HGMs-filled compatibilized PP/PA6 blend. When 50PP50PA6 blend with and without maleated PP is filled with HGMs, rheological characterization shows that the blend viscosity has decreased, indicating improved processability. Dynamic mechanical analysis (DMA) revealed that the incorporation of HGMs into the 50PP50PA6 blend enhances the storage modulus.
