Effect of the Particle Size and Acid Pretreatments on Compatibility and Properties of Recycled HDPE Plastic Bottles Filled with Ground Tyre Powder

With the growing emphasis on decreasing the accumulation of the used tyres in land fills, there has been significant scientific and technological interest to provide with solutions to their recovery and reuse. A new composite material based on reused tyre powder as reinforcement and recycled high-density polyethylene as matrix was studied in this work. The effect of chemical acidic pretreatments performed on the rubber and of the particle size on the behavior of the composite material were evaluated. Powder of reused tyres resulting from industrial grinding processes was separated by sieving in three particle size categories: below 200 mu m, between 200-500 mu m and over 500 mu m. Pretreatments using H(2)SO4, HNO3 , or a 50%, mix of H2SO4 and HNO3 were carried Out over the rubber before composite preparation. Mechanical tensile properties were evaluated to determine the effect of particle size and acid pretreatments on composite properties. Fracture surfaces of composite samples were also evaluated by scanning electron microscopy. Overall, all pretreatments improve the mechanical behavior of the obtained materials. This improvement is attributed to the development of a Surface of the rubber, more Suitable for mechanical adhesion. The effect of the particle size has a stronger influence in the properties of the material than the acidic pretreatments. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 112: 1882-1890, 2009