Dynamic Rheological Studies of Poly(p-phenyleneterephthalamide) and Carbon Nanotube Blends in Sulfuric Acid

International Journal of Molecular Sciences

Yutong Cao¹  Zhaofeng Liu¹  Xianghua Gao¹  Junrong Yu¹  Zuming Hu¹ 

[1] State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, Shanghai 201620, China

关键词: liquid crystalline (LC) solution;    single-walled carbon nanotubes (SWNTs);    rheology;   

DOI  :  10.3390/ijms11041352

来源: mdpi

【 摘 要 】

We have studied the dynamic scanning of liquid-crystalline (LC) poly(p-phenyleneterephthalamide) sulfuric acid (PPTA-H₂SO₄) 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-H₂SO₄ LC solution 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 °C. The PPTA/SWNT/H₂SO₄ solution is in its plateau zone and storage modulus (G′) is a dominant factor within the frequency (ω) range of 0.1–10 rad/s. As ω increases, the G′ rises slightly, in direct proportion to the ω. The loss modulus (G″) does not rise as a function of ω when ω < 1 s⁻¹, then when ω > 1 s⁻¹ G″ increases faster than G′, yet not in any proportion to the ω.

【 授权许可】

CC BY   
© 2010 by the authors; licensee Molecular Diversity Preservation International, Basel, Switzerland.