The preparation of a composite flame retardant of layered double hydroxides and α-zirconium phosphate and its modification for epoxy resin

MFLDH/alpha-ZrP(U), a composite of MgFe layered double hydroxide (MFLDH) and alpha-zirconium phosphate (alpha-ZrP) was prepared by stripping-recombination process under ultrasonication, in order to integrate their excellent physical and chemical functionalities. SEM results depicted that, due to the electrostatic potential difference between the laminates of MFLDH and alpha-ZrP, the stripped MFLDH and alpha-ZrP nanosheets adhere tightly to form a homogeneous layered structure. Subsequently, MFLDH/alpha-ZrP(U) was incorporated into epoxy resin (EP) at a rate of 3 wt% to prepare specimens for investigation of their flame retardancy and mechanical property. Compared to the blank sample, the peak heat release rate (PHRR) could be reduced by 39.1%, the total heat release (THR) could be reduced by 17.0%, the peak CO production rate (PCOPR) and total smoke release (TSR) could be significantly decreased by 42.1% and 33.9%, respectively. In addition, the mechanical experiments showed that the impaired mechanical property of EP caused by the addition of MFLDH can be effectively compensated by the addition of alpha-ZrP component.