Preparation method of homopolymer polypropylene blown film special material

The invention relates to a method for preparing a homopolymer polypropylene blown film special material, which comprises mixing the raw material propylene with a mixture of a main catalyst, a co-catalyst and an electron donor, first pre-polymerizing, and then sending the pre-polymer into a series connection. The two loop reactors are polymerized, and the polymer is flashed, deactivated, dried, pelletized and packaged. The main feature of the catalyst is that the main catalyst has a titanium content of 1.80-3.80% and a magnesium content of 15.0-20.0%. Efficient catalysts, as well as granulation processes, use different antioxidants, slip agents, opening agents and stabilizers than the prior art. Due to the adoption of high-efficiency catalyst and homemade additives, the invention has excellent product quality, the melting number is 11-15g/10min, the isotacticity is 96-97%, the yield strength is greater than 32MPa, and the impact strength (23°C) is greater than 35J/ m, elongation at break greater than 900%, coefficient of friction 0.45. The polypropylene of the present invention is used for blown film production, the film thickness distribution is uniform, the extruder current does not change significantly, and the number of broken films is small.