STRUCTURE-PROPERTY INTERRELATION OF POLYPROPYLENE LIQUID-CRYSTALLINE POLYMER BLENDS

The thermomechanical behaviour and the structure-property interrelatio n 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-scr ew extruder under the appropriate conditions in order to obtain blends with LCP in fibrous form. A series with four different LCP contents h as been prepared, while another series with 5% LCP per weight, at high values of draw ratio and at the same temperature profile has also bee n investigated. All blends exhibit improved mechanical properties, whi le with DSC and DMA experiments further information about the morpholo gy and distribution of the dispersed phase has been obtained. Finally, a simple percolation model, developed elsewhere, has been used to int erpret the reinforcing effect of LCP and the interrelation between the two polymeric phases.