Research on preparation and flame retardancy of melamine-modified flame retardant loofah composites

As a natural plant material with unique porous structure, loofah is used in many fields, but there are still defects in fire safety performance in that its flammability. The melamine-modified flame retardant loofah composites (M-FR-PL) were prepared by impregnation baking method. The experimental synthesis conditions were optimized by L9 (3(4)) orthogonal design. The flame retardancy, heat release rate (HRR), thermal stability and smoke density of the composites were analyzed. M-FR-PL6 prepared under the optimum experimental conditions had good properties: the adsorption rate of flame retardant (AR, %) was 6.8%, the limiting oxygen index (LOI, %) reached 27.5%, the vertical combustion level reached V-0, and the amount of residual char was 17.2% higher than that of loofah. The flame retardant mechanism of M-FR-PL6 was thoroughly discussed by various characterization methods. The peak of the HRR curve of M-FR-PL6 declined compared with loofah, indicating the loofah after melamine flame-retardant treatment has good flame retardancy and smoke suppression properties.