A triblock polymer of formula B-A-B is provided. According to the formula, the symbol A represents a central block which is a statistical copolymer comprising units of a 1,3-diene and more than 50 mol % of ethylene units. The symbols B each represent an end block which is a polyethylene with a melting point of greater than 90 C. and a number-average molar mass of greater than or equal to 2000 g/mol and less than or equal to 10 000 g/mol. The polymer has improved rheological properties relative to a statistical copolymer based on ethylene and 1,3-diene of the same microstructure without changing its mechanical and dynamic or thermal properties.

A triblock polymer of formula B-A-B is provided. According to the formula, the symbol A represents a central block which is a statistical copolymer comprising units of a 1,3-diene and more than 50 mol % of ethylene units. The symbols B each represent an end block which is a polyethylene with a melting point of greater than 90 C. and a number-average molar mass of greater than or equal to 2000 g/mol and less than or equal to 10 000 g/mol. The polymer has improved rheological properties relative to a statistical copolymer based on ethylene and 1,3-diene of the same microstructure without changing its mechanical and dynamic or thermal properties.

A propylene composition comprising: A) from 60 wt % to 75 wt %, of a propylene homopolymer having a Polydispersity Index (P.I.) value from 4.3 to 4.9, a fraction insoluble in xylene at 25 C., higher than 95%, based upon the weight of the propylene homopolymer, and MFR (Melt Flow Rate according to ISO 1133, condition L, at 230 C. and 2.16 kg load) ranging from 20 to 75 g/10 min; B) from 25 wt % to 40 wt %, of a copolymer of propylene with from 46.0 wt % to 49.0 wt %; of ethylene derived units, based upon the weight of the propylene copolymer;
wherein the propylene polymer composition having an intrinsic viscosity of the fraction soluble in xylene at 25 C. between 2.2 to 2.9 dl/g; and the relation:
10.7+1.3MFRa17.7P.I.29.3IV+4.9Xs(I)
between about 40 to about 66; wherein the amount of A+B is equal to 100 wt %.

A method for producing a propylene-based block copolymer produces a propylene-based copolymer that exhibits excellent stereoregularity, rigidity, and impact resistance in a convenient and efficient manner while achieving high polymerization activity. The method for producing a propylene-based block copolymer includes bringing a catalyst into contact with propylene, or propylene and an -olefin, and bringing an electron donor compound into contact with the resulting product to produce a propylene-based block copolymer, the catalyst including a solid catalyst component that includes titanium, magnesium, a halogen, and an internal electron donor compound, a specific organoaluminum compound, and a specific external electron donor compound.

A method for producing a propylene-based block copolymer produces a propylene-based copolymer that exhibits excellent stereoregularity, rigidity, and impact resistance in a convenient and efficient manner while achieving high polymerization activity. The method for producing a propylene-based block copolymer includes bringing a catalyst into contact with propylene, or propylene and an -olefin, and bringing an electron donor compound into contact with the resulting product to produce a propylene-based block copolymer, the catalyst including a solid catalyst component that includes titanium, magnesium, a halogen, and an internal electron donor compound, a specific organoaluminum compound, and a specific external electron donor compound.

A method for producing a thermoplastic elastomer includes forming a first block by copolymerizing a C4-C7 isoolefin monomer and alkylstyrene in the presence of a polymerization initiator; and forming a second block by polymerizing aromatic vinyl monomers. The thermoplastic elastomer comprises the first block and the second block. An amount of unreacted portion of the alkylstyrene during the formation of the first block is maintained at a molar ratio of not more than 1/90 relative to a total amount of the isoolefin monomer. The alkylstyrene is represented by the general formula (1), and the polymerization initiator is represented by the general formula (2).

A method for producing a thermoplastic elastomer includes forming a first block by copolymerizing a C4-C7 isoolefin monomer and alkylstyrene in the presence of a polymerization initiator; and forming a second block by polymerizing aromatic vinyl monomers. The thermoplastic elastomer comprises the first block and the second block. An amount of unreacted portion of the alkylstyrene during the formation of the first block is maintained at a molar ratio of not more than 1/90 relative to a total amount of the isoolefin monomer. The alkylstyrene is represented by the general formula (1), and the polymerization initiator is represented by the general formula (2).

The present disclosure provides a propylene composition made from or containing A) from 60 wt % to 75 wt %, of a propylene homopolymer having a Polydispersity Index (P.I.) value from 4.3 to 4.9, a fraction insoluble in xylene at 25 C., higher than 95%, based upon the weight of the propylene homopolymer, and MFR (Melt Flow Rate according to ISO 1133, condition L, at 230 C. and 2.16 kg load) ranging from 20 to 75 g/10 min; B) from 25 wt % to 40 wt %, of a copolymer of propylene with from 46.0 wt % to 49.0 wt %; of ethylene derived units, based upon the weight of the propylene copolymer; wherein the propylene polymer composition having an intrinsic viscosity of the fraction soluble in xylene at 25 C. between 2.2 to 2.9 dl/g; and the relation:

10.7+1.3MFRa17.7P.I.29.3IV+4.9Xs(I) between about 40 to about 66; wherein MFRa is the melt flow rate of the component A); P.I. is the polydispersity index of component A); IV is the intrinsic viscosity of the fraction soluble in xylene at 25 C.; and Xs is the fraction soluble in xylene at 25 C.; and wherein the amount of A+B is equal to 100 wt %.

The present invention relates to a method for preparing a polyolefin block copolymer, the method comprising: a first step of coordination polymerization of an olefin monomer with a transition metal catalyst in the presence of organozinc; and a second step of continuously adding a diacyl peroxide compound to perform polymerization, and to a polyolefin block copolymer prepared therefrom.

The present invention relates to a method for preparing a polyolefin block copolymer, the method comprising: a first step of coordination polymerization of an olefin monomer with a transition metal catalyst in the presence of organozinc; and a second step of continuously adding a diacyl peroxide compound to perform polymerization, and to a polyolefin block copolymer prepared therefrom.