Rheological Behavior of Polystyrene (PS)/Co-Al Layered Double Hydroxide (LDH) Blend Solution obtained Through Solvent Blending Route: Influence of LDH Loading and Temperature

This investigation deals with the preparation of organically modified Co-Al layered double hydroxide (LDH) and influence of its loading and temperature on the rheological behavior of polystyrene (PS)/Co-Al LDH blends prepared via solvent blending method (SBM). Firstly, Co-Al LDH was synthesized by co-precipitation technique. Thereafter, PS blends with various LDHs content (3, 5 and 7 wt.% with respect to pure PS) were synthesized by SBM. The structural properties of the modified Co-Al LDH were characterized by XRD and FTIR analysis. The d-spacing value of modified LDH was found to be 2.8 nm by XRD analysis. The existence of sulfate groups in the modified LDH was affirmed by FTIR analysis. Rheological studies were done for the prepared samples in the shear rate array of 0.1-100 s(-1) at various temperatures (20, 30 and 40 degrees C). It was observed that the rheology of PS solution is influenced by increasing Co-Al LDH loading, shear rate and temperature. All PS/Co-Al LDH blends showed an increment in their shear viscosity than pure PS. Also, the rheological data were fitted with different models, namely, Power law, Casson, Cross, Sisko, Herschel-Bulkley and Carreau models, to explain the rheological behavior. The results clearly indicated that Herschel-Buckley model displays good fit at lower temperature (20 degrees C), whereas Cross model offers best fit at higher temperatures (30 and 40 degrees C) for both pure PS and PS solution with various concentration of Co-Al LDH. (c) 2017 Elsevier Ltd. All rights reserved.