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 thermoplastic roofing membrane comprising a planar thermoplastic sheet, optionally having more than one layer, where at least one layer of the membrane includes an ethylene-based olefinic block copolymer.

Improved reaction processes comprise reacting a mixture to form a product comprising a metal alkyl, metal oxide, or mixture thereof and then passing said product to a post-reactor heat exchanger. The improvement comprises one or more of the following: (1) reacting said metal alkyl compound with an acid to produce a soluble metal ester; or (2) adding an ionic surfactant; or (3) adding a mixture comprising an antioxidant to the product under conditions sufficient to avoid formation of significant amounts of insoluble metal or metal compounds derived from said metal alkyl compound; or (4) purging said post-reactor heat exchanger with an inert gas under conditions to remove metal oxide from the post-reactor heat exchanger.

Improved reaction processes comprise reacting a mixture to form a product comprising a metal alkyl, metal oxide, or mixture thereof and then passing said product to a post-reactor heat exchanger. The improvement comprises one or more of the following: (1) reacting said metal alkyl compound with an acid to produce a soluble metal ester; or (2) adding an ionic surfactant; or (3) adding a mixture comprising an antioxidant to the product under conditions sufficient to avoid formation of significant amounts of insoluble metal or metal compounds derived from said metal alkyl compound; or (4) purging said post-reactor heat exchanger with an inert gas under conditions to remove metal oxide from the post-reactor heat exchanger.

A process to form a block copolymer comprising two or more regions or segments of differentiated polymer composition or properties, including feeding a first mixture that includes a chain shuttling agent, a solvent, the one or more monomers, and optionally hydrogen into a first reactor or reactor zone, feeding a second mixture that includes at least one olefin polymerization catalyst and at least one cocatalyst into the first reactor or reactor zone, contacting the first mixture and the second mixture under polymerization conditions in the first reactor or reactor zone to form a reaction mixture that is characterized by the formation of polymer chains from the monomers, allowing polymerization to occur in the first reactor or reactor zone and/or a second reactor or reactor zone to form polymer chains that are differentiated from the polymer chains, such that the resultant polymer has two or more chemically or physically distinguishable blocks.

A process to form a block copolymer comprising two or more regions or segments of differentiated polymer composition or properties, including feeding a first mixture that includes a chain shuttling agent, a solvent, the one or more monomers, and optionally hydrogen into a first reactor or reactor zone, feeding a second mixture that includes at least one olefin polymerization catalyst and at least one cocatalyst into the first reactor or reactor zone, contacting the first mixture and the second mixture under polymerization conditions in the first reactor or reactor zone to form a reaction mixture that is characterized by the formation of polymer chains from the monomers, allowing polymerization to occur in the first reactor or reactor zone and/or a second reactor or reactor zone to form polymer chains that are differentiated from the polymer chains, such that the resultant polymer has two or more chemically or physically distinguishable blocks.

An object of the present invention is to prevent an occurrence of flow-mark molding defects to improve an appearance of molded articles, and as a means for achieving the object, a propylene-based block copolymer is used as an appearance improver, the copolymer comprising 80 to 60% by weight of crystalline propylene polymer portion which has an intrinsic viscosity []p of 0.90 dL/g or less and 20 to 40% by weight of propylene/ethylene random copolymer portion which has an ethylene content of 35 to 50% by weight and an intrinsic viscosity []c of 7.0 dL/g or higher ([]c/[]p being 7.5 to 30), in which the propylene-based block copolymer has a MFR of 10 to 50 g/10 min.

A tyre for wheels of vehicles, in particular motor vehicles, is described. The tyre has a tread with at least one copolymer of (iso-styrene/trans-butadiene):diene-terminated copolymers. The tread has less sensitivity to the effects of temperature, with less weakness, better consistency of performances, and improved characteristics in terms of grip and/or resistance to laceration.

Provided are a metallocene complex that facilitates copolymerization of olefin monomers including propylene at a higher uptake rate of comonomers, i.e., ethylene and -olefin, manufacture of a rubber component having a higher molecular weight, and manufacture of homopolypropylene having a higher melting point through homopolymerization of propylene, compared to traditional metallocene catalysts, and a method of olefin polymerization in the presence of such a metallocene complex. Also provided are, for example, a metallocene complex represented by general formula [I] (e.g., a metallocene complex having a substituent at position 6 of one or each indenyl ring and an optionally substituted furyl or thienyl group at position 2 of one or each indenyl ring), an olefin polymerization catalyst containing the metallocene complex, and a method of olefin polymerization involving olefin polymerization or copolymerization in the presence of the olefin polymerization catalyst.

A (iso-styrene/trans-butadiene):diene-terminated copolymer is described which includes (i) a polymeric block of styrene-butadiene consisting of a random sequence of butadiene in trans conformation and styrene in isotactic configuration, and (ii) a terminal polymeric block consisting of a sequence of one or more dienic monomers.