3results about How to "High isotacticity" patented technology

The application relates to the field of high polymer materials, and discloses a 4-methyl-1-pentene homopolymer as well as a preparation method and application thereof. The isotacticity of the 4-methyl-1-pentene homopolymer is greater than or equal to 98%, the flexural modulus is greater than 1100 MPa, and the tensile modulus is greater than 1500 MPa. The 4-methyl-1-pentene homopolymer has the advantages of high isotacticity and good rigidity.

The invention relates to the field of propylene polymerization, and discloses a preparation method of polypropylene, polypropylene and application. The method comprises the following steps: S1, in the presence of a functional external electron donor and a catalyst system, carrying out a prepolymerization reaction on propylene to obtain a prepolymer A; the prepolymerization multiplying power is 1000 to 10000 times; s2, in the presence of a first molecular weight regulator, a first external electron donor and the prepolymer A, performing a first polymerization reaction on propylene to obtain a polymer B; s3, in the presence of a second molecular weight regulator, a second external electron donor and a polymer B, carrying out propylene second polymerization reaction to obtain polypropylene. According to the method, the prepolymerization reaction is combined with the polymerization reaction of two stages, the functional external electron donor is introduced in the prepolymerization process, and the specific first external electron donor and the specific second external electron donor are subsequently matched, so that the prepared polypropylene has good processability and heat resistance.

The invention discloses a chiral bridged metallocene compound as well as a preparation method and application thereof, and the chiral bridged metallocene compound is characterized in that the chiral bridged metallocene compound has a general formula (I): wherein R1 is selected from 4-substituted phenyl; r2 is selected from alkyl; m is selected from one of Ti, Zr and Hf; x is selected from halogen. The catalyst prepared from the chiral bridged metallocene compound has better catalytic activity, the melt index and isotacticity of synthesized polypropylene are improved, and a polypropylene material with better fluidity can be obtained.