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Kevlar (para-aramid) [2] is a strong, heat-resistant synthetic fiber, related to other aramids such as Nomex and Technora.Developed by Stephanie Kwolek at DuPont in 1965, [3] [2] [4] the high-strength material was first used commercially in the early 1970s as a replacement for steel in racing tires.
Same as the small molecular liquid crystal, liquid crystal polymers also have different mesophases. The mesogen cores of the polymers will aggregate into different mesophases: nematics, cholesterics, smectics and compounds with highly polar end groups. [10] More information about the mesophases can be found on liquid crystal page.
Although typically "doping" conductive polymers involves oxidizing or reducing the material, conductive organic polymers associated with a protic solvent may also be "self-doped." Undoped conjugated polymers are semiconductors or insulators. In such compounds, the energy gap can be > 2 eV, which is too great for thermally activated conduction.
[2] [5] In particular, ion conduction in polymer electrolytes is low (compared to liquid and solid-state electrolytes), but blending with inorganic materials has been shown to enhance the ion mobility and conductivity of the polymer electrolyte. The additional benefit is that the desirable properties of the polymer are maintained, particularly ...
Conductive agents are used to ensure electrodes have good charge and discharge performance. Usually, a certain amount of conductive material is added during the production of the pole piece , and the micro current is collected between the active material and the current collector to reduce the micro current.
This material which must have started out like unfired pottery was slip cast from fused silica. Then it was dried four days at 333 K before being tested. It was 9 inches in diameter and 1 inch thick, density 1.78 ⋅ cm −3. The first run went to 1317K and then on the second run the same insulator proved to be more conductive. 1959. [110 ...
Synthetic polymers are ubiquitous in commercial materials and products in everyday use, such as plastics, and rubbers, and are major components of composite materials. Polymer chemistry can also be included in the broader fields of polymer science or even nanotechnology , both of which can be described as encompassing polymer physics and ...
Nomex is an example of a meta variant of the aramids (Kevlar is a para aramid). Unlike Kevlar, Nomex strands cannot align during filament polymerization and have less strength: its ultimate tensile strength is 340 MPa (49,000 psi). [2] However, it has excellent thermal, chemical, and radiation resistance for a polymer material.