Deformation study of the dispersed phase in filled polymer blends using LCP/PP/SiO2 as model systems

The evolution of microstructure in multiphase polymer blends often encompasses the deformation of the dispersed phase during flow. The deformation is usually complex and relies on several interdependent rhelogical and morphological parameters. The effects of inorganic particulate fillers on the deformation of dispersed phases in polymer blends have not been studied systematically despite the ubiquity of such systems. In order to carry out such a systematic study, a model blend system comprising a liquid crystalline polymer as the dispersed phase suspended in a polypropylene matrix in the presence of silica particles was used. A theoretical approach based on the capillary number is proposed for some quantitative analysis of the deformation of the dispersed phase imparted by particulate fillers and shear force. A master curve which reveals the complicated and yet crucial co-relationships between the capillary number and the effects of shear rate and filler content on the extent of deformation is established.