Configuration of Novel Experimental Fractographic Reverse Engineering Approach Based on Relationship between Spectroscopy of Ruptured Surface and Fracture Behaviour of Rubber Sample.

Sanjoy Datta,Evghenii Harea,Martin Stěnička,Ondřej Kratina,Radek Stoček

doi:10.3390/ma13194445

Abstract

A novel fractographic approach based on a combination of (i) mechanical behavior of cured rubber in uniaxial tensile loading and (ii) spectroscopy of fracture on a ruptured surface was experimentally validated. This approach related the migration of paraffin oil from a matrix to the ruptured rubber surface, to the tearing energy related to the deformation speed responsible for total rubber sample rupture, and the approach itself was configured experimentally. It was evaluated on cured natural rubber (NR) for two different paraffin oil concentrations. Single edge notched tensile (SENT) samples were subjected to uniaxial tensile loadings at two different deformation speeds. First, the tearing energy as a function of deformation speed was determined for each defined oil concentration. Secondly, at specific locations on the ruptured surfaces, infrared (IR) spectroscopy was performed to quantify a characteristic absorbance peak height of migrated paraffin oil during the rupture process. The results of the IR analyses were related to the deformation speed to understand the relation between the amount of migrated paraffin oil during the fracture process and the deformation speed which brought about such a fracture. This novel approach enhanced the reverse engineering process of rubber fracture related to the cause of tearing energies during critical failure.

Highlights

Failure of structural components is mostly due to the initiation of micro-cracks and their propagating in macroscopic scale
IR spectra after baseline fitting and subsequent subtraction without Figure deformation, and the alsosuperimposed for the two compositions at two different deformation speeds
The results revealed that the percent changes in all the cases were positive, proving that after redistribution, more of a redistributed concentration of oil was observed at higher tearing energy or at lower deformation speed

Summary

Introduction

Failure of structural components is mostly due to the initiation of micro-cracks and their propagating in macroscopic scale. The increase of fracture resistance by modifying the structure of materials is an important objective of materials science for structural materials such as steel, and for highly deformable rubbery materials. Improving the crack growth resistance of rubber materials has been a very important goal in the rubber industry for a long time [1,2,3]. Rubbery materials are not often used for contemplated products unless they are properly compounded and cured. Some of the more important compounding ingredients used are cross-linking and curing agents, reinforcing fillers, anti-degradants, processing aids, plasticizers or extenders and tackifiers [4], existing as either rigid solid or liquid matter in the rubber matrix

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