Morphology and its influence on rheological parameters of nanocomposites filled with layered silicates based on polylactic acid

In this research work the morphology of polylactic acid (PLA) filled with various types of layered silicates, as well as its influence on the rheological properties regarding melt strength and complex viscosity, were investigated. Thereby the morphology of the produced nanocomposites were examined with small angle X-ray scattering (SAXS) measurements. For the determination of melt strength a Rheotens apparatus, fed by a bypass system during extrusion, was used. Complex viscosities were measured with a rotational rheometer with cone- plate setup. Results show that the different modifications of the layered silicates have a significant impact on the final morphology as well as on the rheological properties of the produced nanocomposites. Beside different achieved interlayer distances and grades of intercalation of the layered silicates inside the polymer matrix, also increased melt strength as well as increased complex viscosities were observed. Thereby a homogenous dispersion and high grade of exfoliation is also preferable for the production of thin products like films. Copyright © (2014) by the Society of Plastics Engineers All rights reserved