Ultrasonic and mechanical measurements for the detection of crosslink density of SBR and NBR based on various curing systems

Abstract

The stress-strain measurements of styrenebutadiene rubber (SBR) samples based on various curing systems were used to access the crosslink density of various rubber mixes. Same materials were subjected to various uniaxial compression strains. The thicknesses before compression and after recovery were recorded. After recovery, pulse echo method was used to measure the ultrasonic velocity for the dilatational wave and that of shear wave at a frequency of 2 MHz and at room temperature. Both of the ultrasonic velocities were used to determine the elastic moduli of the samples. The relation between the elastic moduli and the corresponding recovery values were used to determine the crosslink density of samples. The crosslink density values obtained from the two techniques were compared. Butadiene-acrylonitrile (NBR) rubber mix was used to show that the ultrasonic technique is applicable for other rubber compounds.

Use of waste rubber and bionanofiller in preparation of rubber nanocomposites for friendly environmental flooring applications

“…The plates are held together by three axial bolts. Ringshaped spacers of different thicknesses, 6.00, 7.614 and 9.228 mm, are placed around three axial bolts [32]. The different thicknesses (ls) of the spacers help to control the degree of compression.…”

Investigation of Surface Damages in Composite Materials Using Ultrasonic Lamb Waves

“…If their size is over an acceptable size, they should be repaired or replaced. Otherwise, these errors can cause very big accidents, which may cause the loss of very important Ultrasonic testing (UT) has been proven as one of the best non-destructive testing methods for materials [8,14,15]. Traditional UT techniques are carried out to investigating metals, fiberreinforced composites, polymers, and many different materials [7,9,14,16,17].…”