Interfacial property optimization through the co-deployment of MOF-derived nickel phyllosilicate and DOPO: Effective reinforcement and flame retardancy of epoxy resin

Epoxy resin (EP) is a versatile material widely employed in diverse fields such as electronic encapsulation, coatings, and adhesives. The optimization of flame-retardant, mechanical and interfacial properties in composites through material modification and compounding represents a prominent research focus within the field of EP. This study presents a novel approach by synthesizing MOF-derived nickel phyllosilicate (K–NiPS) and compounding it with 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) into the EP matrix. The incorporation of 5 wt% total K–NiPS and DOPO, with a mass ratio of 2:3, achieves a UL-94 V-0 rating and enhances the limiting oxygen index from 23.5 to 28.8 %. This combination also reduced the peak heat release rate, peak smoke release rate, and total smoke release by 44.6 %, 53.6 %, and 37.8 % respectively. Besides, the interface optimization effect of K–NiPS in collaboration with DOPO improved the tensile strength of EP/2K–NiPS/3DOPO from 77.5 MPa to 94.3 MPa, and the wear rate was only 1.25 × 10⁻⁵ mm³/(N·m), which is 82.2 % lower than that of pure EP. This study will pave the way for the applied interface design of multi-functional EP.