Bio-inspired engineering of boron nitride with iron-derived nanocatalyst toward enhanced fire retardancy of epoxy resin

• Published in: Polymer degradation and stability Vol. 157; pp. 119 - 130
• Main Authors: Li, Zhi, Montero Lira, Sara Isabel, Zhang, Lu, Expósito, Daniel Fernández, Heeralal, Vignesh Babu, Wang, De-Yi
• Format: Journal Article
• Language: English
• Published: London Elsevier Ltd 01-11-2018; Elsevier BV
• Subjects: Boron nitride; Boron-epoxy composites; Catalysts; Epoxy resin; Epoxy resins; Fire protection; Fire retardancy; Flame retardants; Heat conductivity; Heat release rate; Ignition; Interfacial charring; Iron; Nanocomposites; Nanoparticles; Polymers; Safety; Smoke; Thermal conductivity; Boron nitride; Epoxy resin; Fire retardancy; Interfacial charring; Ignition
• ISSN: 0141-3910; 1873-2321
• DOI: 10.1016/j.polymdegradstab.2018.10.005

Aiming at improving fire retardancy of epoxy resin (EP), the thermal-exfoliated boron nitride nanosheets (BN) underwent the bio-inspired polydopamine (PDA) nano-coating and in-situ interfacial growth of iron-derived nanocatalyst (Fe) to prepare nanohybrid (BN@PDA@Fe). The design complied with principles: 1) PDA promoted the dispersion of BN in EP matrix and offered active sites for functionalization 2) bio-stabilized iron-derived nanoparticles catalyzed the polyaromatic reaction towards higher quality. Resultantly, 6 wt% BN@PDA@Fe increased limiting oxygen index (LOI) of EP by 10.0% and suppressed fire spread in UL-94 test. The peak heat release rate (pHRR) was reduced by 38.9% with notably suppressed CO and smoke production. Ignition time, as a key aspect of fire safety, was effectively delayed due to enhanced thermal conductivity of BN-based EP nanocomposites. The optimization of char structure due to the interfacial charring accounted for the improved fire retardancy. In perspective, the bio-inspired engineering of BN offered a viable approach to improving fire safety of polymers.
•Exfoliated BN was hierarchically modified with polydopamine and iron derivatives.•The targeted BN@PDA@Fe showed better dispersion than its counterparts in epoxy resin.•BN@PDA@Fe efficiently suppressed integral fire hazard of epoxy resin.•Ignition of epoxy resin was delayed based on the increased thermal conductivity.•Interfacially catalytic charring toward high-quality char accounted for fire safety.