Behavior of waste tire rubber composites reinforced with waste fibers

In the present study, two types of waste tire rubber particles, powder (TRP) and granules (TRG), are characterized to evaluate their behavior as a matrix in reinforced composite samples based on waste wool fibers (WWF) and waste glass fibers (WGlF). Waste tire rubber was first characterized by Fourier Transform Infrared Spectroscopy, Thermogravimetric Analysis, Differential Scanning Calorimetry and X-ray photoelectron spectrometry. Wasted fibers were characterized in terms of surface morphology, length, diameter and correspondent FTIR spectrums were also analyzed. Composites were then prepared using a Taguchi experimental design to evaluate the influence of the size of particles (powder and granules), the reinforcement rate (0.2%, 0.4% and 0.6%) and the consolidation time (45 min, 60 min and 75 min) on composite porosity, tensile strength and hardness. Samples were prepared using a thermopressing process at 180°C, under a compression force of 2 MPa. The optimum process parameters ensuring high tensile strength of the composite were: TRP as matrix and WWF (0.6%) as reinforcement during 75 min consolidation time. 0.6% WWF reinforcement rate contributes to a 64.7% increase in tensile strength and to a 19.5% increase in hardness. Reinforcement of waste tire rubber (WTR) with waste fibers reduces the porosity of composite materials, especially using WGlF.