Detection of undercure in carbon-fibre/epoxy composites by dynamic mechanical thermal analysis
Desirable properties in thermosetting polymer matrix composites can only be realised after a sufficient degree of matrix curing. It is, thus, important that the state of cure should be clearly identified. Carbon-fibre/epoxy laminates of varying degrees of matrix cure were prepared, and evaluated using static mechanical tests, impact tests and dynamic mechanical thermal analysis. Interlaminar shear and compression tests, although widely used in quality control, were not sufficiently sensitive to distinguish between the cured and significantly undercured laminates. Furthermore, considerable scatter was experienced in the interlaminar shear strength measurements