Structure and property relationship
Derradji Dadache; Farid Rouabah; Zahir Rahem
Abstract
This study demonstrates that quenching and annealing significantly influence the mechanical and thermophysical behavior of low density polyethylene (LDPE). Rapid quenching at temperature of –25 °C enhances ductility by increasing elongation at break, despite reducing thermophysical properties, ...
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This study demonstrates that quenching and annealing significantly influence the mechanical and thermophysical behavior of low density polyethylene (LDPE). Rapid quenching at temperature of –25 °C enhances ductility by increasing elongation at break, despite reducing thermophysical properties, likely due to microstructural refinement. In contrast, post-quenching annealing especially at 100 °C improves thermal conductivity and crystallinity but reduces ductility. The results underscore a tunable balance between thermal and mechanical performance, governed by the interplay of beta (β-) and alpha (α-) relaxation modes during heat treatment. Post-quenching annealing of low density polyethylene LDPE, particularly at 100 °C, significantly enhanced thermal conductivity, diffusivity, and crystallinity, albeit with a trade-off in ductility and increased brittleness. Quenching within the beta (β-) relaxation range promoted maximum ductility, while annealing in the alpha (α-) relaxation range improved thermophysical properties. These findings reveal that precise control of heat treatment conditions enables a tunable balance between mechanical flexibility and thermophysical performance in LDPE
Structure and property relationship
Leila Latreche; Samira Maou; Lokmane-Taha Abdi; Tahir Habila; Yazid Meftah
Abstract
Polypropylene (PP) is a strong, tough, crystalline thermoplastic material with high performance. Because of its diverse thermo-physical and mechanical properties, it is utilized in a wide variety of disciplines. In this study, the impact of free quenching on the thermo-physical characteristics of PP/calcium ...
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Polypropylene (PP) is a strong, tough, crystalline thermoplastic material with high performance. Because of its diverse thermo-physical and mechanical properties, it is utilized in a wide variety of disciplines. In this study, the impact of free quenching on the thermo-physical characteristics of PP/calcium carbonate (CaCO3) composites was examined. Three distinct heating procedures were used. First, composites were cooled from their melting phase temperature to ambient temperature. Second, composites were cooled from 130°C to a pre-determined and controlled temperature (T: 0°, 20°, 30°, 40°, 50°, 60°, 70°, 80°C). Third, composites were temperature-tested using annealing. The findings suggest that the elongation-at-break and impact strength may be improved following an initial quenching process from the melting phase to ambient temperature. On the other hand, a second quenching process at 0°C produces superior results, and a correlation between mechanical and thermal characteristics is noted; however, while these qualities are increased, others, such as flexibility, density, Vicat softening temperature (VST), and heat distortion temperature (HDT) are negatively impacted.
