Effect from Surface Modification on Fibers on the Mechanical Properties of Composites of Poly (Butylene Terephthalate) Reinforced with Inorganic Natural Fibers

This work aims to investigate the viability of natural amorphous silicate short fibers (FNSA) as reinforcing agent of thermoplastic engineering polymers, and their possible use as an alternative to short glass fibers in industrial applications. Different surface modifications were performed in order to improve interface adhesion between the matrix and FNSA, and consequently improve mechanical properties. The surface treatments of FNSA were applied with silane coupling agents provided with different organofunctional groups. PBT was chosen as matrix due to its easy manufacturing process even after incorporation of large quantities of additives. The surface chemistry after modification was evaluated through thermogravimetric analyses coupled to a Fourier transformed infrared spectroscopy equipment. Mechanical resistance and composite fracture were investigated through tensile tests and image analyses by scanning electron microscopy. Finally, the tensile strength of modified fibers reinforced PBT was 40% higher than neat PBT.