Abstract:
Ground tyre rubber (GTR) was blended with waste polypropylene (WPP) in nine
different compositions to prepare GTRIWPP blends. The blends were prepared
in a Haake Rheocord PolyLab system at a temperature of 180 °C and a rotor
speed of 30 r/min for 8 min. The processing characteristics of the blends showed
an increase in steady-state mixing torque with an increase in GTR content,
suggesting an increased difficulty in processability at GTR loadings above
30 wt.%. Morphological observations of the blends showed two-phase systems.
The GTR was dispersed in a continuous WPP matrix in blends containing up to
60 wt.% GTR, and the size of the dispersed GTR agglomerates increased with
GTR content. At 70 wt.%, the GTR dispersed phase changed to a continuous
phase. Tensilestrength, modulus, and tear resistance decreased with GTR content,
while the elongation at break and the impact failure energy increased. All these
properties remained relatively unchanged at low GTR contents, suggesting
that a critical GTR level is required to obtain rubber-like properties in a simple
rubber-thermoplastic blend.
