Nanocomposites based on polyethylene and Mg-Al layered double hydroxide. Part II. Rheological characterization

The rheological properties of Mg-Al based layered double hydroxide (LDH)/polyethylene nanocomposites have been presented in details. Both unmodified and maleic anhydride (MAH) grafted polyethylene based composites are characterised. The X-ray diffraction and electron microscopic investigations reveals the primary structures of the dispersed LDH particles exists as thin platelets. The rheological analysis carried out under different modes show behaviors typical of those reported extensively in literature for various cationic clay based polymer nanocomposites. The dispersed LDH particles show stronger interaction with maleic anhydride grafted matrix. The influence of LDH loading increases the shear thinning nature of the composite melt. The storage modulus vs. frequency plots of the composites show apparent plateau behaviors in low frequency region in a dynamic frequency sweep experiment. The appearance of stress overshoot peak in flow reversal experiment indicates that the dispersed LDH particles form structural aggregation, which are ruptured by shearing, but reform with time when shearing is stopped.