Ad
related to: amorphous vs semi crystalline plastics for sale home depot
Search results
Results from the WOW.Com Content Network
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 ]
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 ...
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 ...
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 ...
Although the two phases are chemically equivalent, semi-crystalline polymers can be described both quantitatively and qualitatively as composite materials. The crystalline portion has a higher elastic modulus and provides reinforcement for the less stiff, amorphous phase.
Amorphous and semi-amorphous plastics are less resistant to chemical attack and environmental stress cracking because they lack a crystalline structure. Brittleness can be decreased with the addition of plasticizers , which increases the mobility of amorphous chain segments to effectively lower the glass transition temperature.
Thermally processed material is usually totally amorphous, [7] and as a result is highly transparent to visible light, with better light transmission than many kinds of glass. Polycarbonate has a glass transition temperature of about 147 °C (297 °F), [8] so it softens gradually above this point and flows above about 155 °C (311 °F). [9]
Ad
related to: amorphous vs semi crystalline plastics for sale home depot