| 摘要 |
Branched polypropylene compositions which have improved melt strength and good processability are provided. The branched polypropylene compositions of the present invention have a polydispersity of less than 4.0 and a melt point greater than 90 DEG C. Further, the weight average branching index g of the polypropylene compositions is less than 0.95. Additionally, a novel process is provided for efficiently producing a branched polypropylene composition comprising: a) contacting propylene monomers in a reactor with an inert hydrocarbon solvent or diluent and a catalyst composition comprising one or more single site catalyst compounds capable of producing stereospecific polypropylene at a temperature from about 40 DEG C to about 120 DEG C, wherein the ratio in the reactor of the propylene monomers to the inert hydrocarbon solvent or diluent is less than 9.0, and further, wherein the propylene monomers and the inert hydrocarbon solvent or diluent comprise at least 50 weight percent of the total contents of the reactor; and b) recovering a branched polypropylene composition having a polydispersity of less than or equal to 4.0 and a melting point greater than 90 DEG C wherein the weight average branching index, g, of the branched polypropylene composition is less than 0.95.
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