Influence of processing conditions on the morphological and mechanical properties of compatibilized PP/LCP blends

• Published in: Journal of applied polymer science 2007-08, Vol.105 (3), p.1521-1532
• Main Authors: Filipe, Susana, Manuel Maia, João, Rosa Leal, Catarina, Teresa Cidade, Maria
• Format: Article
• Language: English
• Subjects: Applied sciences; Blends; Exact sciences and technology; Isotactic polyproylene; Liquid crystalline polymers; Machinery and processing; Moulding compound preparation. Mixing; Plastics; Polymer industry, paints, wood; Processing conditions; Technology of polymers; Thermoplastic
• ISSN: 0021-8995; 1097-4628
• DOI: 10.1002/app.26412

The main aim of this work is to study theinfluence of the application of different processing conditionson the morphological and mechanical properties of thermo-plastic/LCP blends, in which the viscosity ratios are inferiorto unity and decrease with increasing temperature. The waythe microstructure evolves along the extruder determines thefinal morphology and thus, the mechanical performance ofthe systems. In the present case, the mechanical properties arerelated with the degree of fibrillation in the final composites.The best degree of fibrillation was obtained for low screwspeeds and temperatures and for intermediate outputs. Theuse of high screw speeds and processing temperatures resultsin a decrease of the viscosity ratio, in the former case via anincrease in the viscous dissipation, at the regions of highershear rates (kneading-elements). The application of a lowerprocessing temperature is advantageous for deformation,break-up, and fibrillar formation because of the higher viscos-ity ratios and higher shear stresses involved.