A New HM-HT Fiber

Two methods have proved effective in preparing high modulus, high tenacity polymer fibers  

With a view to improved economics in the case of scaling up, Sikkema et al. developed syntheses of the monomers based on epi-chlorohydrin, HCN and ammonia for 2,6-diaminopyridine [21] and for DHTA based on hydroquinone and COj [30]. 

Krauss, and Kleiss describe a facile preparation of the terephthal-ate salt of 4,6-diaminoresorcinol [31]. Thus, copolymers employing both DHTA and terephthalic acid (TPA) necessitated use of TAP phosphate and TPA next to TD complex. Such copol5miers showed lower relative viscosities when more TPA was used as a comonomer, and became insoluble in the polymerization medium when more than 50% of DHTA was substituted by TPA. 

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