Twaron

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.

The invention of this specific process was done in 1974 at AKZO Research Laboratory in Arnhem by a team consisting of Leo Vollbracht, Teun Veerman (assistant of Leo Vollbracht) and Wim Engelhard (trainee, who actually discovered NMP as the appropriate solvent to keep the growing polymer as long as possible in solution; he also discovered that high speed mixing of PPD and TDC was necessary to obtain a sufficiently long polymer chains).

Despite heavy research DuPont now also applies the AKZO patent for their Kevlar process and use the less hazardous NMP.

Polymer solvent for spinning PPTA is generally 100% anhydrous (water free) sulfuric acid (H2SO4).

Twaron is a para-aramid and has automotive, construction, sports, aerospace, and military applications, e.g., in modern body armor, fabric, and as an asbestos substitute.

Rifle protection police shield used by the National Police of Colombia . Stops 7.62 mm and 5.56 mm caliber rounds. Made from light ceramics and Twaron.