Effect of maleimide curing on mechanical properties of ground tyre rubber/waste polypropylene blends

Abstract

Blends of ground tyre rubber and waste polypropylene with a maleimide curing system (50 : 50 blends of ground tyre rubber/waste polypropylene) were prepared in a Haake Rheocord Polylab System, at 180uC and 90 rev min -1 for 5 min. The curing agent and the activator used were N,N9meta-phenylene dimaleimide (HVA-2) and di(tert-butylperoxyisopropyl) benzene (DTBPIB) respectively. The HVA-2 level varied from 0 to 5 parts per hundred parts (pphp), while the DTBPIB level varied from 0 to 1 pphp. Melt viscosity, tensile strength and elongation at break showed an increase with HVA-2 content, while the impact energy showed an optimum at 3 pphp level. The addition of the DTBPIB increased melt viscosity further and produced a homogeneous phase morphology of the blends. Impact energy improved with the DTBPIB level, while elongation at break and tensile strength showed an optimum at 0?6 pphp. Swelling behaviour and gel/sol from the boiled xylene extractions were studied, and the results obtained were correlated with the impact and tensile properties.

Thermoplastic elastomers based on recycled high-density polyethylene/ground tire rubber/ethylene vinyl acetate: Effect of ground tire rubber regeneration on morphological and mechanical properties

“…This observation is in agreement with other reports showing that GTR particles contain some soluble molecules which can absorb the solvent and swell. 43 Increasing the GTR content by 10% (from 70 to 80 wt.%) in RHD/GTR blends increased the swelling degree of N80 from 138 to 145%, while the swelling degree of RR 1 and RR 2 blends increased from 160% to 169% and from 172% to 180%, respectively. This difference is attributed to the lower resistance to non-polar solvents of partially destroyed crosslinked structure of RR particles which promotes swelling.…”