Polyethylene (PE) is a thermoplastic resin obtained by polymerization of monomer ethylene. It has good cold resistance, good mechanical strength and dielectric properties. It is widely used in cables, films, pipes, packaging, containers, medical appliances and other products. However, the oxygen index of PE is 17.4%, which is a flammable material. PE material has high combustion speed, high heat/smoke, and easy to melt droplets during combustion, which poses a great threat to the safety of life and property, and limits the use and development of polyethylene. Therefore, it is necessary to carry out flame retardant modification.
Aluminum hydroxide and magnesium hydroxide are the main flame retardants. Mg-al flame retardant has good stability, non-toxic and small amount of smoke. In the process of combustion, water vapor will be released to dilute combustible gas, take away some heat, inhibit combustion and produce flame retardant effect. Aluminum-magnesium flame retardant can prolong the ignition time and reduce the heat release rate. Magnesium hydroxide has poor compatibility with PE and low flame retardant efficiency, so it is necessary to add a large amount of magnesium hydroxide to improve the flame retardant performance, and a large amount of magnesium hydroxide will reduce the processing and mechanical properties of the composite.