Optimizing the magnetocuring of epoxy resins via electromagnetic additives

• Main Authors: Chaudhary, Richa, Chaudhary, Varun, Suda, Yoshiyuki, Ramanujan, Raju V., Steele, Terry W. J.
• Other Authors: School of Materials Science and Engineering
• Format: Article
• Language: English
• Published: 2021
• Subjects: Engineering::Materials::Functional materials; Engineering::Materials::Magnetic materials; Engineering::Materials::Composite materials; Engineering::Manufacturing::Polymers and plastics; Adhesives; Carbon Nanotubes; Carbon Nanocoils; Curie Magnetic Nanoparticles; Thermosets; Thermoplastics
• Online Access: https://hdl.handle.net/10356/152517
• Institution: Nanyang Technological University

Magnetocuring of adhesives refers to the curing of an epoxy + Curie temperature controlled magnetic nanoparticles (CNP) composite using a suitable alternating magnetic field. The controlled heating of the CNP results in remote, wireless curing without resin overheating. However, typical CNP possess only a fraction of the heat output of ferric oxide nanoparticles, quantified as the specific absorption rate (SAR). Previous investigations of epoxy + CNP adhesives revealed a SAR of 5 W.g−1, which is 10–100× less than that of ferric oxides. Here, it is demonstrated that SAR can be improved to up to 60 W.g−1 by tuning CNP composition and by the addition of carbon allotropes (CA) within the resin. Heat generation and dissipation can be also regulated by electromagnetic shielding, resin conductivity, and viscosity. Nanocoils and nanotubes of CA result in improved heating profiles of epoxy thermosets. Magnetocured composites achieve activation within 180 s due to the improved SAR and addition of CA. Remarkably, under optimized conditions, a relatively stable one-pot adhesive was formed by magnetocuring of epoxy + CNP + CA composites without a hardener.