Micrographs of fractured vinyl ester composites

Abstract

This paper reports the difference in impact strength between microwave cured vinyl ester particulate composites and those cured under ambient conditions by examining the micrographs of the fractured specimens. Drop weight impact test had been used to fracture the samples. The original contribution of this paper is to tell the fracture behaviour of the samples as well as the relative toughness of the specimens by viewing their micrographs. The results show that the difference in the impact strength between optimally (lower power and longer exposure duration) microwave cured samples and those cured under ambient conditions is minimal. However, if the specimens were cured using higher power, the resulting toughness of the samples would be lower as many voids would form in the samples due to the initial expansion of the composite.