Viscoelastic properties of polyarylene ether nitriles/thermotropic liquid crystalline polymer blend
writer：Wu,Defeng，Zhang, Yisheng，Wu, Lanfeng，Jin, Lifeng，Zhang, Ming，Zhou, Weidong，Yan, Changhao
keywords：polyarylene ether nitriles; thermotropic liquid
source：期刊
specific source：Journal of Applied Polymer Science
Issue time：2008年
Polyarylene ether nitriles (PEN)/thermotropic liquid crystalline polymer (TLCP) blend was prepared via melt mixing. The immiscible phase morphologies, linear and nonlinear, as well as transient viscoelastic properties of the blend were studied using SEM, rheometer, and DMA. The linear dynamic viscoelastic behavior of the blend shows temperature dependence due to further evolution of the immiscible morphology and, as a result, the principle of time-temperature superposition (TTS) is invalid. In the steady shear flow, the discrete TLCP phase is difficult to be broken up because of the high viscosity ratio of the blend systems, while is easy to be coarsened and followed by elongation, and finally, to form fibrous morphology at high TLCP content and high shear level. During this morphological evolution process, the transient stress response presents step increase and nonzero residual relaxation behavior, leading to increase of the dynamic viscoelastic responses after steady preshear.