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Twaron is the brandname of Teijin Aramid for a para-aramid.
Additional recommended knowledge
Twaron is a heat-resistant and strong synthetic fiber developed in the early 1970s by the Dutch company AKZO, division Enka, later Akzo Industrial Fibers. The research name of the para-aramid fiber was originally Fiber X, but it was soon called Arenka. Although the Dutch para-aramid fiber was developed only a little later than DuPont's Kevlar, introduction of Twaron as a commercial product came much later than Kevlar due to financial problems at the AKZO company in the 1970s.
A short overview of the history of Twaron:
Twaron is a p-phenylene terephtalamide (PpPTA), the simplest form of the AABB para polyaramide. PpPTA is a product of p-phenylene diamine (PPD) and terephtaloyl dichloride (TDC). To dissolve the aromatic polymer Twaron used a co-solvent of N-methyl pyrrolidone (NMP) and an ionic component (Calcium Chloride (CaCl2) to occupy the hydrogen bonds of the amide groups. Prior to the invention of this process by Leo Vollbracht, working at the Dutch chemical firm AKZO, no practical means of dissolving the polymer was known. The use of this system by DuPont led to a patent war between AKZO and DuPont as Dupont initially used the carcinogenic HMPT (Hexamethylphosphoramide). Despite heavy research DuPont now also uses the AKZO patent to use the less hazardous NMP in the Kevlar process.
After the production of the Twaron polymer in Delfzijl, the polymer is brought to Emmen, where fibers are produced by spinning the dissolved polymer into a solid fiber from a liquid chemical blend. Polymer solvent for spinning PPTA is generally 100% (water free) sulphuric acid (H2SO4). The polymer is dissolved by mixing frozen sulphuric acid in powder form with the polymer in powder form and gently heating the mixture. This process, which differs from the more difficult DuPont process, was invented by Henri Lammers and patented by AKZO.
Major industrial uses
|This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Twaron". A list of authors is available in Wikipedia.|