As to these problems,for instance,the poor compatibility between the traditional flame retardant of expandable graphite and the matrix of polyethylene,the fly ashes,the large amount of smoke and the poor flame retardant effect,the flame retardant of expandable graphite coated by bismuth oxide hydroxide was prepared by hydrothermal synthesis,and then the hybrid flame retardant was mixed uniformly with polyethylene to achieve the flame retardant composite. The expandable graphite coated by bismuth oxide hydro...