FIELD: organic chemistry. SUBSTANCE: method involves treatment of linear polypropylene showing amorphous or crystalline structure mainly in the absence of atmospheric oxygen. Treatment is carried out by polymer mixing at 70-100 C with peroxide with low decomposition point and showing half-life time 0.5 min at 100 C and 20 min at 70 C at peroxide concentration 0.0079-0.0467 mmole/g polymer in mixer following by keeping of prepared mixture at 70-100 C for 10-120 min up to peroxide decomposition. Then additional treatment of polypropylene is carried out by temperature increase up to 140-150 C and keeping at this temperature for 90 min or less. Di-(sec.-butyl)-peroxydicarbonate is used as peroxide with low decomposition point. Before peroxide addition polypropylene can be heated and kept for 20 s (not less). Polypropylene treatment can be performed by polymer mixing with two peroxides, one of which has high decomposition point (40 h at 100 C and 30 min at 150 C), and other one is peroxide with low decomposition point. Peroxide with high decomposition point is 2,5-dimethyl-2,5-bis-(tert.-butylperoxy)-hexane. EFFECT: improved method of polypropylene preparing. 5 cl, 5 dwg, 2 tbl
