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Crystallization affects optical, mechanical, thermal and chemical properties of the polymer. The degree of crystallinity is estimated by different analytical methods and it typically ranges between 10 and 80%, with crystallized polymers often called "semi-crystalline". The properties of semi-crystalline polymers are determined not only by the ...
The crystallinity of the polymer can be measured through differential scanning calorimetry. [8] For amorphous and semicrystalline polymers, as stress is applied, the polymer chains are able to disentangle and align. If the stress is applied in the direction of chain alignment, the polymer chains will exhibit a higher yield stress and strength ...
Strain crystallization occurs when the chains of molecules in a material become ordered during deformation activities in some polymers and elastomers. [2] The three primary factors that affect strain crystallization are the molecular structure of the polymer or elastomer, the temperature, and the deformation being applied to the material. [3]
[citation needed] The two materials have very different properties because the irregular structure of the atactic version makes it impossible for the polymer chains to stack in a regular fashion: whereas syndiotactic PS is a semicrystalline material, the more common atactic version cannot crystallize and forms a glass instead.
Crystal growth is a major stage of a crystallization process, and consists of the addition of new atoms, ions, or polymer strings into the characteristic arrangement of the crystalline lattice. [ 1 ] [ 2 ] The growth typically follows an initial stage of either homogeneous or heterogeneous (surface catalyzed) nucleation , unless a "seed ...
Formation of spherulites affects many properties of the polymer material; in particular, crystallinity, density, tensile strength and Young's modulus of polymers increase during spherulization. This increase is due to the lamellae fraction within the spherulites, where the molecules are more densely packed than in the amorphous phase.
Attributes of the resulting crystal depend largely on factors such as temperature, air pressure, cooling rate, and in the case of liquid crystals, time of fluid evaporation. Crystallization occurs in two major steps. The first is nucleation, the appearance of a crystalline phase from either a supercooled liquid or a supersaturated solvent.
Crystallinity refers to the degree of structural order in a solid. In a crystal, the atoms or molecules are arranged in a regular, periodic manner. The degree of crystallinity has a large influence on hardness, density, transparency and diffusion. In an ideal gas, the relative positions of the atoms or molecules are completely random.