Effect of steady shear on the microstructural evolution of melt-intercalated polymer/clay nanocomposites
writer：Wu,Defeng，Zhou, Chixing，Zhang, Ming
keywords：clay; nanocomposites; polyesters; shear
source：期刊
specific source：Journal of Applied Polymer Science
Issue time：2007年
A sheet sample composed of poly(butylene
terephthalate) and clay prepared by solid-state compression
was melt-annealed in a rheometer under steady shear flow
to investigate the whole hybridization process. The results
of the offline morphology and thermogravimetric analysis
as well as Fourier transform infrared characterization show
that shear flow can reduce the dynamic process of hybridization,
facilitating the formation of an intercalated nanoscale
structure. With an increase in the shear intensity, the
detachment level of clay increases more remarkably than the
swollen degree. However, an increase in the shear intensity does not induce an exfoliated structure but can decrease the
average thickness of the clay tactoids, leading to a remarkable
enhancement in the thermal stability due to the increase
in the effective filling volume of the clay. Furthermore, those
intercalated nanocomposites annealed at a high shear rate
still present a distinct hierarchical structure, which suggests
that steady shear is not as good as dynamic or complex shear
for promoting hybridization effectively.