The invention relates to a low-
diffusion polypropylene composition which comprises the following components in percentage by weight: 55-99.8 percent of
polypropylene composite material and 0.2-5 percent of organopolysiloxane
silicone oil, wherein the organopolysiloxane
silicone oil comprises one or a plurality of
hydrogen-type polysiloxane, hydroxyl polysiloxane,
methyl polysiloxane, ethenyl polysiloxane, amino polysiloxane,
epoxy polysiloxane and methoxyl polysiloxane
silicone oil. A preparation method of the low-
diffusion polypropylene composition comprises the following steps of: weighing the components of polypropylene, talcum
powder, a
toughening agent, an
antioxidant, a light stabilizer and the organopolysiloxane
silicone oil in percentage by weight; mixing the polypropylene, the
toughening agent, the
antioxidant, the light stabilizer and the organopolysiloxane
silicone oil for 1-2 minutes in a high speed mixer firstly and then adding the talcum
powder and mixing for 3-5 minutes; and extruding and
pelletizing the
mixed materials by using a double screw extruder, wherein the
process conditions are that: the temperature of a first area is 200-210 DEG C, the temperature of a second area is 210-220 DEG C, the temperature of a third area is 210-220 DEG C and the temperature of a fourth area is 200-215 DEG C, the
retention time is 1-2 minutes, and the pressure is 10-20MPa. The low-
diffusion polypropylene composition has the advantages that: the organopolysiloxane
silicone oil forms a layer of even film on the surface of the talcum
powder, which can block up a TVOC (
Total Volatile Organic Compound) of the polypropylene material so as to reduce the
pollution.