Damage Precursor Detection in Polymer Matrix Composites Using Cyclobutane-Containing Crosslinked Polymer

Identification of damage precursors in polymer matrix composite structures is important. We applied cyclobutane-containing crosslinked polymer as a crack sensor dispersed in epoxy. The crosslinked polymer will identify damage precursors through stress induced fluorescent emission. The emergence of cracks was detected by fluorescence at a strain level beyond the yield point of the composite and the fluorescence intensified with accumulation of strain. In the current work, we synthesize smart particles of cyclobutane-containing crosslinked polymer as novel embedded sensing and dispersed those particles into the matrix. The critical stress threshold and the relationship of stress-spectroscopic signal are studied.