Mechanical and electrical properties of a polyester resin reinforced with clay-based fillers

Abstract : In this study, composite polymer-based materials, in which a significant proportion of polyester resin has been substituted by low cost and environmentally friendly clay-based raw materials, have been elaborated. The main objective is to improve mechanical properties keeping a reasonable electrical insulating behavior. A homogenized distribution of fillers within the matrix compatible with the processing parameters has been obtained up to a maximum added fraction of 20vol%. Mechanical characterizations performed with uniaxial traction tests and Charpy impact pendulum machine have shown that stress to rupture can be enhanced of about 25% and that fracture energy value has double for the best formulations. Dielectric constant decreases and loss factor slightly increases while electrical resistivi-ty remains almost invariable. From a general point of view, composite materials with metakaolin fillers exhibit higher mechanical properties and a greater electrical insulating behavior. Microstructural observations revealed the presence of decohesive agglomerates of particles at the interface with the matrix. Finally, mechanical properties are more sensitive to the homogeneity of fillers dispersion in the matrix than electrical properties.