Application of the synergistic flame retardant europium hydrotalcite/graphene oxide hybrid material and zinc borate to thermoplastic polyurethane

In this paper, a certain amount of rare earth (europium) was doped into magnesium aluminum salt solution and assembled with graphene oxide (GO) by electrostatic interaction under alkaline conditions. Then, the EuMgAl-LDH/GO hybrid material was synthesized by a hydrothermal method. Its microstructure was analyzed and tested by X-ray diffraction (XRD), energy dispersive spectrometry (EDS), transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR), the results indicated that the EuMgAl-LDH/GO hybrid material had been successfully prepared. Next, it was mixed with zinc borate and added to a thermoplastic polyurethane (TPU) (thermoplastic polyurethane) matrix by melting blending. The flame retardant and smoke suppression effect of the composite was tested by conical calorimetry. The results showed that, compared with simple TPU, the PHRR (peak heat release rate), THR (total heat release), PSPR (peak smoke production rate) and TSP (total smoke production) value of the composite material decreased by 65.6%, 16.2%, 61% and 37.1%, respectively. Finally, through analysis of the carbon residue after combustion of the TPU composite material, we found that the formed carbon layer is denser and the char yield is greatly improved.