The invention discloses a preparation method of modified
expanded polystyrene. The preparation method of the modified
expanded polystyrene comprises the following steps: adding di(dioctyl phosphite)
tetraisopropyl titanate into
acetone, uniformly stirring, then adding carbon nano tubes for carrying out
ultrasonic dispersion, and
drying to obtain a nucleating agent; adding water,
barium stearate, activated
calcium phosphate, nekal, a defoaming agent, an
antioxidant, a
flame retardant and
styrene into a reaction container, uniformly stirring, then sequentially adding
dibenzoyl peroxide, tert-butyl peroxybenzoate,
dicumyl peroxide and the nucleating agent, uniformly stirring, heating up to the temperature of 90 DEG C, and carrying out heat preservation for 3-4 hours, so that
polystyrene is obtained; adding liquid butadiene-
acrylonitrile rubber and
melamine formaldehyde resin into a reaction container containing
polystyrene, heating up to the temperature of 100-110 DEG C, uniformly stirring, adding a
foaming agent, and carrying out heat preservation for 3-4 hours, wherein pressure in a heat preservation process is 1-1.2MPa; and cooling to
room temperature, and filtering, so that the modified
expanded polystyrene is obtained.