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Crystalline polymers are usually opaque because of light scattering on the numerous boundaries between the crystalline and amorphous regions. The density of such boundaries is lower in polymers with very low crystallinity (amorphous polymer) or very high degree of crystalline polymers, consequentially, the transparency is higher. [ 5 ]
Polymer morphology is a microscale property that is largely dictated by the amorphous or crystalline portions of the polymer chains and their influence on each other. Microscopy techniques are especially useful in determining these microscale properties, as the domains created by the polymer morphology are large enough to be viewed using modern ...
By varying the monomer ratios and method by which the monomers are combined different forms of EPM can be formed (with a wide range of Mooney viscosities); ranging from amorphous to semi-crystalline. A third, non-conjugated diene monomer can be terpolymerized in a controlled manner to maintain an unsaturated backbone ready for vulcanization or ...
Many plastics are completely amorphous (without a highly ordered molecular structure), [22] including thermosets, polystyrene, and methyl methacrylate (PMMA). Crystalline plastics exhibit a pattern of more regularly spaced atoms, such as high-density polyethylene (HDPE), polybutylene terephthalate (PBT), and polyether ether ketone (PEEK ...
In condensed matter physics and materials science, an amorphous solid (or non-crystalline solid) is a solid that lacks the long-range order that is characteristic of a crystal. The terms " glass " and "glassy solid" are sometimes used synonymously with amorphous solid; however, these terms refer specifically to amorphous materials that undergo ...
Polyamorphism is also an important area in pharmaceutical science. The amorphous form of a drug typically has much better aqueous solubility (compared to the analogous crystalline form) but the actual local structure in an amorphous pharmaceutical can be different, depending on the method used to form the amorphous phase.
Amorphous solids are the opposite of crystalline. The atoms or molecules in amorphous substances are arranged randomly without any long-range order. As a result, they do not have a sharp melting point. The phase transition from solid to liquid occurs over a range of temperatures. [citation needed] Some examples include glass, rubber and some ...
In polymer physics, spherulites (from Greek sphaira = ball and lithos = stone) are spherical semicrystalline regions inside non-branched linear polymers. Their formation is associated with crystallization of polymers from the melt and is controlled by several parameters such as the number of nucleation sites, structure of the polymer molecules, cooling rate, etc. Depending on those parameters ...