%0 Journal Article
%T Dynamic Rheological Studies of Poly(p-phenyleneterephthalamide) and Carbon Nanotube Blends in Sulfuric Acid
%A Yutong Cao
%A Zhaofeng Liu
%A Xianghua Gao
%A Junrong Yu
%A Zuming Hu
%A Ziqi Liang
%J International Journal of Molecular Sciences
%D 2010
%I MDPI AG
%R 10.3390/ijms11041352
%X We have studied the dynamic scanning of liquid-crystalline(LC) poly( p-phenyleneterephthalamide) sulfuric acid (PPTA-H 2SO 4) solution, and its blend with single-walled carbon nanotubes (SWNTs), by using a flat plate rotational rheometer. The effects of weight concentration and molecular weight of PPTA, as well as operating temperature, on dynamic viscoelasticity of the PPTA-H 2SO 4 LCsolution system are discussed. The transition from a biphasic system to a single-phase LC occurs in the weight concentration range of SWNTs from 0.1% to 0.2%, in which complex viscosity reaches the maximum at 0.2 wt% and the minimum at 0.1 wt%, respectively, of SWNTs. With increasing SWNT weight concentration, the endothermic peak temperature increases from 73.6 to 79.9 ¡ãC. The PPTA/SWNT/H 2SO 4 solution is in its plateau zone and storage modulus ( G¡ä) is a dominant factor within the frequency ( ¦Ø) range of 0.1¨C10 rad/s. As w increases, the G¡ä rises slightly, in direct proportion to the w. The loss modulus ( G¡ä¡ä) does not rise as a function of ¦Ø when ¦Ø < 1 s £¿1, then when ¦Ø > 1 s £¿1 G¡ä¡ä increases faster than G¡ä, yet not in any proportion to the ¦Ø.
%K liquid crystalline (LC) solution
%K single-walled carbon nanotubes (SWNTs)
%K rheology
%U http://www.mdpi.com/1422-0067/11/4/1352