Structure-Property Interrelation of Polypropylene-Liquid Crystalline Polymer Blends

The thermomechanical behaviour and the structure-property interrelation for blends based on a thermotropic liquid crystalline polymer (LCP) with a thermoplastic semicrystalline polymer as polypropylene (PP) was investigated. The polymeric materials were melt blended in a twin-screw extruder under the appropriate conditions in order to obtain blends with LCP in fibrous form. A series with four different LCP contents has been prepared, while another series with 5% LCP per weight, at high values of draw ratio and at the same temperature profile has also been investigated. All blends exhibit improved mechanical properties, while with DSC and DMA experiments further information about the morphology and distribution of the dispersed phase has been obtained. Finally, a simple percolation model, developed elsewhere, has been used to interpret the reinforcing effect of LCP and the interrelation between the two polymeric phases.