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Semi-crystalline polymers with strong crystalline regions resist deformation and cavitation, the formation of voids in the amorphous phase, drives yielding. [25] As done in crystalline materials, particles can be added to semi-crystalline polymers to change the mechanical properties.
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 a 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 ...
In many materials that normally undergo a freezing transition, rapid cooling will avoid this phase transition and instead result in a glass transition at some lower temperature. Other materials, such as many polymers, lack a well defined crystalline state and easily form glasses, even upon very slow cooling or compression. The tendency for a ...
All polymers (amorphous or semi-crystalline) go through glass transitions. The glass-transition temperature (T g) is a crucial physical parameter for polymer manufacturing, processing, and use. Below T g, molecular motions are frozen and polymers are brittle and glassy. Above T g, molecular motions are activated and polymers are rubbery and ...
Common examples include chocolates, candles, or viruses. Water ice and dry ice are examples of other materials with molecular bonding. [22] Polymer materials generally will form crystalline regions, but the lengths of the molecules usually prevent complete crystallization—and sometimes polymers are completely amorphous.
It is analogous to the polymorphism of crystalline materials. Many amorphous substances can exist with different amorphous characteristics (e.g. polymers). However, polyamorphism requires two distinct amorphous states with a clear, discontinuous (first-order) phase transition between them.
Vitrification (from Latin vitrum 'glass', via French vitrifier) is the full or partial transformation of a substance into a glass, [1] that is to say, a non-crystalline or amorphous solid. Glasses differ from liquids structurally and glasses possess a higher degree of connectivity with the same Hausdorff dimensionality of bonds as crystals: dim ...
The orientation of crystallites can be random with no preferred direction, called random texture, or directed, possibly due to growth and processing conditions.While the structure of a single crystal is highly ordered and its lattice is continuous and unbroken, amorphous materials, such as glass and many polymers, are non-crystalline and do not display any structures, as their constituents are ...