12. Partial phase diagram of poly(p-phenylene terephthalamide) copolymers in sulfuric acid
writer：Wei Wang, Matthias C. Hund, Günter Lieser, Gerhard Wegner
keywords：phase diagram; copolymers; synthesis
source：期刊
specific source：Polymer
Issue time：1992年
Copolyaramides with 2,5-di-n-hexyl terephthalic acid residues as comonomers were synthesized. Partial phase diagrams were measured for mixtures with concentrated sulfuric acid in the range between 8 and 20% w/w of polymer. Lyotropic phases were observed, but in comparison to homopoly(p-phenylene terephthalamide) the clearing temperatures are lower and the critical concentrations for the formation of the lyotropic nematic phase are increased. The existence of a master curve for the clearing temperature as it depends on the concentration of the components of both homo- and copolymers illustrates that the side chains act mainly as an ‘attached solvent’ to the rigid main chains.