Environmental stress cracking (ESC) of ABS

The environmental stress cracking (ESC) of acrylonitrile-butadiene-styrene (ABS) co-polymer caused by a non-ionic surfactant (poly-oxyethylene alkylether) was studied by constant-load tensile creep tests and edge crack tension (ECT) tests. The fracture surfaces were investigated by scanning electron microscope (SEM) and the morphology of the crack tip was investigated by transmission electron microscope (TEM). It was found that the results of the creep tests performed in the non-ionic surfactant was very different from those in air. SEM images of the fracture surfaces showed that there were three different mechanisms of fracture and that specimens had a tendency to rupture by ESC when stress was small. The results of the ECT tests and the TEM images showed that the change in the mechanism of fracture was attributable to the change of morphology at the crack tip.