WebSep 25, 2024 · As an estimate, some say the melt density of amorphous polymers is about 90% of the solid density, and the melt density of semi-crystalline polymers is about 80% of the solid density; but as you can see from Table 2, that is not very accurate, as the molecular structure also enters into the change in density from solid to melt, regardless … WebThe crystalline–amorphous nanostructure exhibits an ultra-high yield strength of ~1.80 GPa, an ultimate tensile strength of ~2.3 GPa, and a large uniform strain of ~7.0%. By finite element analysis, the authors claimed the synergetic deformation mechanisms between amorphous phase and crystalline phase.
12.1: Crystalline and Amorphous Solids - Chemistry LibreTexts
WebNov 13, 2024 · In polyethylene-based materials, the amorphous component and the crystalline diffractions can be regularly deduced using a fitting program [46,47,48,49]. This allows the decomposition of the X-ray patterns and, consequently, the estimation of the resulting crystallinity. WebImportant intrinsic factors of the crystal phase are crystal structure, crystal thickness, and degree of crystallinity, and those of the amorphous phase are free volume, entanglement density, and chain stiffness. ninja blender and food processor youtube
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Below their glass transition temperature, amorphous polymers are usually hard and brittle because of the low mobility of their molecules. Increasing the temperature induces molecular motion resulting in the typical rubber-elastic properties. A constant force applied to a polymer at temperatures above Tg results in a viscoelastic deformation, i.e., the polymer begins to creep. Heat resistance is usually given for amorphous polymers just below the glass transition temperature. WebJan 30, 2024 · Crystalline polymers have large amorphous areas, which is why we call them semi-crystalline polymers. Semi-crystallines also have sharp melt points. While … WebAug 23, 2024 · Highly branched polymers can also exhibit a lower degree of crystallinity, as can be seen when comparing the more branched low density polyethylene (LDPE), … nuffiled health careers