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  2. Crystallization of polymers - Wikipedia

    en.wikipedia.org/wiki/Crystallization_of_polymers

    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]

  3. Amorphous solid - Wikipedia

    en.wikipedia.org/wiki/Amorphous_solid

    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 ...

  4. Polymer - Wikipedia

    en.wikipedia.org/wiki/Polymer

    The crystallinity of polymers is characterized by their degree of crystallinity, ranging from zero for a completely non-crystalline polymer to one for a theoretical completely crystalline polymer. Polymers with microcrystalline regions are generally tougher (can be bent more without breaking) and more impact-resistant than totally amorphous ...

  5. Polypropylene - Wikipedia

    en.wikipedia.org/wiki/Polypropylene

    This has an impact on the crystallinity (amorphous or semi-crystalline) and the thermal properties (expressed as glass transition point T g and melting point T m). The term tacticity describes for polypropylene how the methyl group is oriented in the polymer chain. Commercial polypropylene is usually isotactic.

  6. Polymer characterization - Wikipedia

    en.wikipedia.org/wiki/Polymer_characterization

    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 ...

  7. Polyethylene terephthalate - Wikipedia

    en.wikipedia.org/wiki/Polyethylene_terephthalate

    Depending on its processing and thermal history, polyethylene terephthalate may exist both as an amorphous (transparent) and as a semi-crystalline polymer. The semicrystalline material might appear transparent (particle size less than 500 nm ) or opaque and white (particle size up to a few micrometers ) depending on its crystal structure and ...

  8. Polyphthalamide - Wikipedia

    en.wikipedia.org/wiki/Polyphthalamide

    The properties of semicrystalline polymers v amorphous polymers are described elsewhere in detail. Briefly, crystallinity helps with chemical resistance and mechanical properties above the glass transition temperature (but below the melting point). Amorphous polymers are good in warpage and transparency.

  9. Polyethylene - Wikipedia

    en.wikipedia.org/wiki/Polyethylene

    The less the polymer chains are branched, and the lower the molecular weight, the higher the crystallinity of polyethylene. Crystallinity ranges from 35% (PE-LD/PE-LLD) to 80% (PE-HD). Polyethylene has a density of 1.0 g/cm 3 in crystalline regions and 0.86 g/cm 3 in amorphous regions. An almost linear relationship exists between density and ...