Effect of Post-Cure on Flexural Properties of Plain-Woven Glass Fabric/Vinyl Ester Composites

摘要

The effect of post-cure on flexural properties of plain-woven glass fabric/ vinyl ester composites was investigated by three-point bending test. The post-cure of composites was carried out in order to the post-cure duration at the constant temperature; 80℃ for 4, 8, 12, 16, 24h, and non post-cure. The types of the specimens define as Oh, 4h, 8h, 12h, 16h and 24h. It was found from the experimental results that the flexural strength and the flexural modulus increased due to the post-cure. The upward tendency of these material properties was shown for post-cured materials except 24h specimen. The linear behavior appeared in the load-displacement curve of the post-cured specimens. On the other hands, the non-linear behavior in the load-displacement curve in non post-cured type appeared with increasing applied load. The microscopic observation for edge-wise direction was carried out in order to estimate the degree of the internal damage. Delamination occurred in the case of the low post-cure time types (i.e. non post-cure, 4h) and prolonged post-cure time type (24h). Matrix cracking occurred at middle post-cure time types (i.e. 8h, 12h, 16h). It was suggested from these results that the post-cure enhanced the flexural properties of plain-woven glass fabric/vinyl ester composites, due to increasing the adhesive strength of the fiber-matrix interface. It was also found that the prolonged post-cure time has weakened the adhesive strength at the fiber-matrix interface.