Stress-Responsive Reinforced Polymer Composites via Functionalization of Glass Fibers

Debonding and delamination in fiber reinforced polymer composites has been a prevailing challenge in modern composite applications, as this form of precursor damage can be crucial to understanding failure in these types of composites. Mechanochemistry may offer a unique solution to monitor these failure modes through the use of mechanophores: molecular units which undergo a specific chemical reaction through mechanical deformation of highly strained bonds present in the molecule. In this work, the fluorescent cinnamoyl mechanophore is grafted to the surface of a glass fiber and incorporated into a glass fiber reinforced polymer (GFRP) composite to monitor the mechanophore activation during loading. Additionally, a thermal and mechanical study is performed to understand the effect of mechanophore surface functionalization on property changes of the resulting composite. This work is indeed successful at producing a composite capable of detecting interphase stresses and damage through monitoring of the fluorescent cinnamoyl mechanophore, allowing for an understanding of how this damage initiates in the material.