A comparison of the mechanical behaviour of natural rubber-based blends using waste rubber particles obtained by cryogrinding and high-shear mixing
Nicolas Candau
, Rachel LeBlanc, Maria Lluisa Maspoch
, Rachel LeBlanc, Maria Lluisa MaspochVol. 17., No.11., Pages 1135-1153, 2023
DOI: 10.3144/expresspolymlett.2023.86
DOI: 10.3144/expresspolymlett.2023.86
Corresponding author: Nicolas Candau 
GRAPHICAL ABSTRACT
ABSTRACT
The
influence of the type of mechanical recycling of waste rubber particles on the
tensile properties of waste/natural rubber blends has been investigated. The
wastes originating from ground tyre rubber (GTR) had been treated by two
distinct processes: cryo-grinding and high shear mixing (HSM). For both
processes, the resulting composites show enhanced stiffness and strength for
all strain rates and temperatures tested. This is attributed to both the
reinforcing effect of the waste as well as the nucleation ability of the wastes
on strain induced crystallization (SIC) in the natural rubber (NR) matrix.
Cryo-grinding was shown to provide the finest particle size with an average
diameter of 34 μm, while the HSM process was found to show an elastic modulus
of aggregated GTR powder of 7 MPa at 1 Hz at room temperature. Within these
characteristics, the NR/GTR blends using the HSM process show the best tensile
performance under single loading, with the highest strength and highest ability
to crystallize under strain. Under cyclic loading, NR/GTR blends using
cryo-ground GTR particles show the best performance, which we ascribed to their
ability to better distribute and accommodate the stress from one cycle to another
owing to their finest size. Both explored recycling techniques provide the
natural/waste rubber blends interesting properties such as mechanical
reinforcement and strain-induced crystallization ability under various testing
conditions.
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