Self‐Healing Clay/Epoxy Composites Prepared from Clay‐Modified Microcapsules

Abstract

Urea‐formaldehyde microcapsules were made in the presence of montmorillonite (MMT) nanoparticles by in‐situ polymerization and characterized with different methods. To monitor the presence of MMT and Dicyclopentadiene in microcapsules. Fourier‐transform infrared spectroscopy (FTIR) spectra was taken from samples. Distribution of microcapsule‘s diameters was studied by optical microscopy (OM) micrographs. Size distribution analysis showed that the average diameter of the microcapsules decreased from 130 (in the neat microcapsules) to 85 μm in MMT modified microcapsules. Surface and shell wall of microcapsules have an important role in their capability. Therefore, surface roughness and shell barrier properties were investigated by AFM micrographs and Thermogravimetry analysis. Results of both the methods showed improved features in MMT modified microcapsules. The synthesized microcapsules were used in MMT/epoxy nanocomposite as the healing agent and a coated glass monitored under optical microscope before and after crack demonstrating a good healing observed after 2 hours.

Investigation of microcapsules based self-healing composites embedded with carbon nanotubes for improved healing efficiency

“…Raj Kumar et al, have reported epoxy-PMMA based microcapsules with healing efficiencies of neat epoxy and CFRP with microcapsules were 72% and 53%, respectively [22]. DCPD-Montmorillonite (MMT) nanoparticle-based microcapsules showed a decrease in diameter and better response to temperature [23,24]. Our previous studies have shown that dual-core microcapsules containing DCPD-CNT and UF resulted in improved thermal and electrical properties with the incorporation of MWCNT [25].…”

Development and characterization of self-healing microcapsules, and optimization of production parameters for microcapsule diameter and core content

“…Organic polymers such as urea-formaldehyde (UF), polyurethane, polyurea and melamine-formaldehyde are used to form the shell of MCs (Zhang et al, 2022;Lee, 2001). UF resins in this shell material are preferred because of their fast curing, high reactivity, nonflammability and low cost (Khostavan et al, 2022). Emulsion polymerization is utilized to generate a UF shell by aggregation and condensation processes.…”

“…, 2022; Lee, 2001). UF resins in this shell material are preferred because of their fast curing, high reactivity, nonflammability and low cost (Khostavan et al. , 2022).…”