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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.
Liquid-crystal polymers are present in melted/liquid or solid form. [7] In solid form, the main example of lyotropic LCPs is the commercial aramid known as Kevlar . The chemical structure of this aramid consists of linearly substituted aromatic rings linked by amide groups.
The samples demonstrated similar depth, but the neat Kevlar displayed more yarn-pullout and yarn splaying. Observers found that the STF-Kevlar was able to withstand the stab test better than the neat Kevlar. Later on, in a spike impactor stab test, the STF-Kevlar demonstrated significantly better results than the neat Kevlar.
Eventually you can find out from his graph that the (1) at the end is not part of his formula and instead he is citing his graph. Air and thin air and high tech vacuums, microstructure Formula Values d=1 millimeter Standard Atmospheric Pressure 0.0209 0.0235 0.0260 0.1 atmosphere 0.0209 0.0235 0.0259 0.01 atmospheres 0.0205 0.0230 0.0254 0.001 ...
Conduction is the main mode of heat transfer for solid materials because the strong inter-molecular forces allow the vibrations of particles to be easily transmitted, in comparison to liquids and gases. Liquids have weaker inter-molecular forces and more space between the particles, which makes the vibrations of particles harder to transmit ...
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.
Dense gases such as xenon and dichlorodifluoromethane have low thermal conductivity. An exception, sulfur hexafluoride, a dense gas, has a relatively high thermal conductivity due to its high heat capacity. Argon and krypton, gases denser than air, are often used in insulated glazing (double paned windows) to improve their insulation ...
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.