Fatigue Properties and Fracture Morphology of Micronised Rubber Powder (MRP) from Waste Tyres in Unfilled Elastomers

Abstract—Ground rubber from waste tyres may be added to elastomers with economic and environmental benefits. The untreated or treated fillers have been investigated in different types of virgin rubber matrix. A principal concern is their crosslinked structure and large particle sizes. These additives introduce flaws leading to micro-crack initiation especially under dynamic loading. The incorporation of smaller particles at a suitable concentration may avoid deterioration in the key properties.
The present work studies the effect of commercial cryogenic micronised rubber particle (MRP) (apparent particle size diameter less than 100 μm) as filler at either 10 or 30 parts per hundred rubber (pphr) on the fatigue properties of natural rubber (NR), butadiene rubber (BR) or NR/BR blends (without carbon black in the host matrix). In non-crystallising rubber, BR compound containing MRP shows an enhancement in the fatigue properties. However, in NR and NR/BR blends the fatigue properties are reduced. Scanning electron microscope (SEM) observations have been used to correlate the fatigue properties with the morphology of the fracture surfaces. For NR or higher ratio of NR matrix, a scale-like texture dominated the fatigue behaviour of the compound. The fracture surface of MRP-filled compound had increased surface roughness compared to their control compound.

Index Terms—Elastomer, fatigue properties, fatigue fracture morphology, micronised rubber powder, unfilled.

Dayang Habibah A. I. H. is with the School of Engineering, University of Plymouth, Plymouth PL4 8AA, United Kingdom, on leave from the Malaysian Rubber Board, Selangor, Malaysia (e-mail: dyghabibah@gmail.com).
Frank Abraham and John Summerscales are with the School of Engineering, University of Plymouth, Plymouth PL4 8AA, United Kingdom (e-mail: frank.abraham@plymouth.ac.uk, J.Summerscales@plymouth.ac.uk).
Paul Brown is with Tun Abdul Razak Research Centre (TARRC), Malaysian Rubber Board, Brickendonbury, Hertford, SG13 8NL, United Kingdom (e-mail: PBrown@tarrc.co.uk).

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Cite: Dayang Habibah A. I. H, Frank Abraham, John Summerscales, and Paul Brown, "Fatigue Properties and Fracture Morphology of Micronised Rubber Powder (MRP) from Waste Tyres in Unfilled Elastomers," International Journal of Materials, Mechanics and Manufacturing vol. 6, no. 4, pp. 281-285, 2018.