Avaliação do comportamento reológico e propriedades mecânicas de compósitos de polipropileno contendo partículas de talco obtidas por diferentes rotas de processamento

Abstract

The objective of this work was to evaluate the mechanical and reheological properties of polypropylene/talc composites in which the surface of talc has been modified by organosilanes. The talc samples were obtained trough an innovative wet grinding process aiming maximum delamination and, consequently, maximum aspect ratio. Theresults were compared with talc obtained by traditional dry grinding technologies such as jet milling. The morphological modifications created on talcs crystalline structure by different grinding processes were characterized by using different particle size distribution techniques.Scanning electron microscopy, thermal analysis, mechanical tests (tensile and flexural), x-ray diffraction and rheology of torque were used in the characterization and technical evaluation of raw materials and the final composites as well. The results showed an increase in the mechanical properties of compounds that have used talc with a high aspect ration, when compared to the compound with talc of lower aspect ration. The surface treatment of talc with lower aspect ratio did not allow to reach the same properties of compounds using the talc with greater delamination, indicating that the increase in particle aspect ratio has more influence on the properties of compounds than the surface treatment with silane can provide