Halogen-free flame-retardant polyvinyl alcohol foam material and preparation method thereof

The invention discloses a halogen-free flame-retardant polyvinyl alcohol foam material and a preparation method of the halogen-free flame-retardant polyvinyl alcohol foam material. The preparation method comprises the steps of preparing composite powder by uniformly mixing 100 parts of polyvinyl alcohol, 20-35 parts of nitrogen-phosphorus halogen-free flame retardant, 0.1-10 parts of catalyst and 0.1-10 parts of nucleating agent, adding the composite powder into mixed solution formed by 0.1-10 parts of surface active agent, 0.1-10 parts of cross-linking agent and 30-40 parts of plasticizing foaming agent, and swelling sufficiently at the temperature of 60 DEG C-80 DEG C, and then continuously extruding and foaming to obtain the halogen-free flame-retardant polyvinyl alcohol foam material at the temperature of 140 DEG C-180 DEG C and with the pressure 8-10MPa. According to the halogen-free flame-retardant polyvinyl alcohol foam material provided by the invention, the limit oxygen index reaches 36%, the vertical burning reaches L94-V0 level and the material can extinguish automatically without fire, the halogen-free flame-retardant property is good, the hole density of the foaming material can be improved, and the halogen-free flame-retardant polyvinyl alcohol foam material can be widely applied to the fields of heat insulation, sound isolation, shock absorption, packaging, sport equipment, clothes and back cushions, soles, sofa, cushions and the like. In addition, the foam is extruded continuously by melting, so that the preparation process is simple, low in cost and environment-friendly, and the halogen-free flame-retardant polyvinyl alcohol foam material is suitable for large-scale industrial production.