Simulation & Modeling
Utkarsh A. Patil; Pravin Ramchandra Kubade
Abstract
This study explores the development of high-density polyethylene (HDPE) composites reinforced with stearic acid-treated expanded perlite (TEP) to examine their thermal, mechanical, and processing properties. The composites were fabricated using a plastograph at 200°C, incorporating perlite concentrations ...
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This study explores the development of high-density polyethylene (HDPE) composites reinforced with stearic acid-treated expanded perlite (TEP) to examine their thermal, mechanical, and processing properties. The composites were fabricated using a plastograph at 200°C, incorporating perlite concentrations from 5% to 20% by volume. The effects of stearic acid (SA) treatment and perlite content were analyzed through SEM, melt flow index (MFI), tensile and impact testing, and thermal analysis (DSC, TGA, and Vicat softening temperature). SEM analysis revealed that untreated perlite exhibited a highly porous structure, while HCl treatment induced fragmentation. At 5% SA, perlite particles were well dispersed with a thin coating, whereas at 10% SA, the coating was more pronounced, leading to agglomeration. The MFI increased with perlite loading, reaching 12.3 g/10 min at 20% perlite, compared to 8.88 g/10 min for neat HDPE. Mechanical testing showed that the elastic modulus increased by 36% (786 MPa) at 5% perlite, dropped to 460.8 MPa at 15%, and rose again to 707.7 MPa at 20%, suggesting structural reinforcement. Moderate perlite content (5-10%) preserved ductility, while higher concentrations (15-20%), especially with 10% SA, increased brittleness due to reduced interfacial adhesion. Thermal analysis showed a slight decrease in melting temperature and a slight increase in crystallization temperature with the addition of treated perlite, while thermal stability improved and the Vicat softening temperature remained unchanged. These results highlight the potential of SA-treated expanded perlite as a viable alternative to conventional fillers, offering a balance between stiffness, ductility, and thermal resistance. The developed composites are promising for light weight and cost-effective applications in energy management and construction.
Structure and property relationship
Igor Chmutin; Ludmila Novokshonova; Petr Brevnov; Guzel Yukhayeva; Natalia Ryvkina
Abstract
There are described nanocomposites based on ultra high molecular weight polyethylene and graphite nanoplates prepared by in-situ polymerization method. It is carried out a comprehensive study of electric properties of these composites, including direct current (dc) and alternating current (ac) properties. ...
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There are described nanocomposites based on ultra high molecular weight polyethylene and graphite nanoplates prepared by in-situ polymerization method. It is carried out a comprehensive study of electric properties of these composites, including direct current (dc) and alternating current (ac) properties. There is explored dependence of the conductivity and dielectric permeability on filler concentration, temperature, deformation and frequency of electric field. These relationships are compared with those for composites based on other carbon fillers including both nanoscale (carbon nanotubes, carbon black) and micron-sized (graphite, schungite) fillers. More specific electrical properties of investigated materials such as lower percolation threshold and higher dielectric permittivity compared to those for composites based on other carbon fillers are attributed to the plate-like shape of graphite nanoplates. These materials are distinguished also by their high electrical stability against temperature and deformation. Therefore, it makes graphite nanoplates the most preferable conductive filler for some practical applications. Some possible application areas for UHMWPE/graphite nanoplates nanocomposites will be also discussed.
Catalysis
He-Xin Zhang; Seung-Ri Lee; Dong-Ho Lee; Xue-Quan Zhang; Keun-Byoung Yoon
Abstract
Despite the great potential of graphene as a nanofiller, achieving homogeneous dispersion remains the key challenge for effectively reinforcing polyolefin (such as polyethylene (PE) and polypropylene (PP)) nanocomposites. Therefore, in this research, we report a facile combined in situ polymerization ...
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Despite the great potential of graphene as a nanofiller, achieving homogeneous dispersion remains the key challenge for effectively reinforcing polyolefin (such as polyethylene (PE) and polypropylene (PP)) nanocomposites. Therefore, in this research, we report a facile combined in situ polymerization and masterbatch method for fabricating PP/reduced graphene oxide (rGO) nanocomposites. In the polymerization stage, the synthesized catalyst exhibited a very high activity toward propylene polymerization, while the resultant PP/rGO with a very high isotactic index (I.I. = 99.3), broad molecular weight distribution (Mw/Mn = 14.9), and thermal stability was produced. After meltblending with commercial PP, a significantly increased modulus along with no observable change in tensile strength and elongation-at-break were achieved via the addition of a very small amount of rGO; these properties resulted from the suitable dispersion and good interface adhesion of the graphene sheet and PP matrix. Thus, this work provides a method for production of high performance PP.
