ORGS3-1530
Directing Chain Alignment with Plasticizers for Ultra-Low Strain Mechanophoric Epoxy Coatings
Topic
GS3. Graduate Student Oral Session III: Polymer Synthesis, Structure, Properties, and Processing
When and Where
Sep 28, 2026
14:36 - 14:48
Room 103
Session Chairs
Jiwon KIM
Junmin LEE
Youngwoon KO
Presenter(s)
Sana Ashqar (Department of Materials Science and Engineering, Technion – Israel Institute of Technology)
Co-Author(s)
Abstract
Mechanophores are molecular-level strain sensors that have a proven record of detecting damage in materials; however, their sensitivity in bulk materials is often lacking, hindering widespread commercial use. This can be explained as a function of polymer chain mobility, as the mechanophores align with the strain field, leading to activation; however, little is known about the role that plasticizer additives may play. In this study, we use spiropyran (SP) as a model system to detect strain at 0.38% within an epoxy coating network on aluminum. To improve the ductility and strain sensitivity, we investigated the effect of different plasticizer mechanisms on both SP activation and intrinsic mechanical properties. Results show the mechanism of plasticization either through free volume expansion or swelling offers distinct control over SP sensitivity and increases toughness under uniaxial tension and bending. Crucially, this reveals mechanophore activation does not depend merely on macroscopic softening of the matrix, rather, it is driven by how specific plasticizers facilitate local chain alignment and effectively funnel mechanical stress directly to mechanophores. Our work highlights how plasticizer selection can be used to balance mechanical performance and damage-sensing capability in SP-functionalized epoxy systems, making them far more suitable for a wider variety of commercial applications.
