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Kevlar (para-aramid) [2] is a strong, heat-resistant synthetic fiber, related to other aramids such as Nomex and Technora. ... The polymers she had been working with, ...
Molecular structure of Kevlar Molecular structure of the LCP Vectran [5]. Liquid crystallinity in polymers may occur either by dissolving a polymer in a solvent (lyotropic liquid-crystal polymers) or by heating a polymer above its glass or melting transition point (thermotropic liquid-crystal polymers). [6]
Well-known aramid polymers such as Kevlar, Twaron, Nomex, New Star, and Teijinconex) are prepared from diamine and diacid (or equivalent) precursors. These polymers can be further classified according to the linkages on the aromatic subunits. Nomex, Teijinconex, and New Star contain predominantly the meta-linkage.
From these two "liquid crystal polymers" (the first ever prepared), fibres were spun that displayed unprecedented stiffness and tensile strength. The innovative polymer Poly-p-phenylene terephthalamide, as invented by Kwolek, was released commercially under the name Kevlar. [9]
The plastic kits and covers are mostly made of synthetic polymers like polythene, and tires are manufactured from polybutadienes. [1] However, due to the environmental issues created by these synthetic polymers which are mostly non-biodegradable and often synthesized from petroleum, alternatives like bioplastics are also being considered. They ...
Polymer chemistry is a sub-discipline of chemistry that focuses on the structures, chemical synthesis, and chemical and physical properties of polymers and macromolecules. The principles and methods used within polymer chemistry are also applicable through a wide range of other chemistry sub-disciplines like organic chemistry , analytical ...
p-Phenylenediamine (PPD) is an organic compound with the formula C 6 H 4 (NH 2) 2.This derivative of aniline is a white solid, but samples can darken due to air oxidation. [1] It is mainly used as a component of engineering polymers and composites like kevlar.
It is one of two precursors used to make Kevlar, the other being p-phenylenediamine. TCL is used as a key component in performance polymers and aramid fibers, where it imparts flame resistance, chemical resistance, temperature stability, light weight, and very high strength.