A polyolefin-polystyrene-based multiblock copolymer and method of making the same are disclosed herein. In some embodiments, a polyolefin-polystyrene-based multiblock copolymer satisfies conditions (a) a weight average molecular weight is 100,000 to 300,000 g/mol; (b) molecular weight distribution is 1.5 to 3.0; (c) measured results of gel permeation chromatography, a graph having an x-axis of log Mw and a y-axis of dw/dlog Mw, are fit to a Gaussian function, where all constants satisfy −0.01<A<0.03, 4.8<B<5.2, 0.8<C<1.2, and 0.6<D<1.2; and (d) a polyolefin block comprises one or more branch points, where a carbon atom at the branch point is represented by a peak of 36 to 40 ppm, and a terminal carbon atom of a branched chain from the branch point is represented by a peak of 13 to 15 ppm.

A polymer composition and a process for the production of this composition comprising a base resin is disclosed herein. The base resin includes a very high molecular weight component, a low molecular weight component, and a high molecular weight component having a weight average molecular weight higher than the weight average molecular weight of the low molecular weight component but lower than the weight average molecular weight of the very high molecular weight component. An amount of the very high molecular weight component in the base resin is 0.5 to 8 wt %. The very high molecular weight component has a viscosity average molecular weight of greater than 1100 kg/mol. The composition has FRR.sub.21/5 of equal to or greater than 38, a melt flow rate MFR.sub.21 of equal to or greater than 6.5 g/10 min and a viscosity at a shear stress of 747 Pa (eta747) of 450 to 3000 kPas.

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.

A tire has an outer sidewall, said outer sidewall comprising at least one composition comprising an elastomeric matrix which predominantly comprises by weight one or more thermoplastic elastomers comprising at least one elastomer block and at least one thermoplastic block, the elastomer block(s) being saturated.

A block copolymer composition is disclosed. The composition contains an elastomeric block copolymer and a hydrophilic fumed silica with a surface area (BET, measured by nitrogen gas adsorption) of at least 200 m.sup.2/g, and a pH of 3 to 5, a tamped density of <=75 g/L. The block copolymer composition forms free-flowing composition, requiring less than 400 lbs/ft.sup.2 to break in a blocking test. The free-flowing composition does not negatively impact haze, transparency, and yellowness of transparent compounds, suitable for use in transparent formulations for medical, toys, and overmolds, viscosified oils, and oil gels applications.

A tire (1) comprises a tread (3), a crown with a crown reinforcement (2), two sidewalls (5), two beads (4), a carcass reinforcement (6) anchored to the two beads (4) and extending from one sidewall (5) to the other, the tread comprising (a) an elastomeric matrix which comprises predominantly one or more thermoplastic elastomers comprising at least one elastomer block and at least one thermoplastic block, and (b) a crosslinking system based on one or more peroxides. The invention also relates to a process for preparing the tire.

Semi-crystalline, thermoplastic polyolefin block copolymers comprising: (A) A first polyolefin A block comprising isotactic poly(1-butene) (iPB); (B) A polyolefin B block comprising an ethylene and/or alpha-olefin/1-butene copolymer or terpolymer; and (C) A second polyolefin A block comprising isotactic poly(1-butene) (iPB); the A and B blocks bonded to one another to form a block copolymer in which the first and second polyolefin A blocks are joined to and separated by the polyolefin B block. In one embodiment the polyolefin block copolymer is a BAB block copolymer.

The present invention relates to a method for preparing a polyolefin-polystyrene-based multiblock copolymer having a uniform structure and showing excellent physical properties through continuous type coordination polymerization and batch type anionic polymerization.

A semicrystalline multiblock copolymer includes alternating blocks of semicrystalline isotactic polypropylene (iPP) and semicrystalline polyethylene (PE), having a block arrangement according to formula (I):

(iPP.sub.w).sub.p(PE.sub.x)(iPP.sub.y).sub.m(PE.sub.z).sub.n   (I),

wherein p is 0 or 1; m is 0 or 1; n is 0 or 1; the sum of p, m, and n is 1, 2, or 3; and the sum of w, x, y, and z is greater than or equal to 40 kg/mol, with the provisos that: when m and n are 0, the sum of w and x is greater than or equal to 140 kg/mol; and when p and n are 0, the sum of y and x is greater than or equal to 140 kg/mol. Related compositions and methods are also provided.

The present disclosure relates to a catalyst system for use in forming a multi-block copolymer, said copolymer containing therein two or more segments or blocks differing in chemical or physical properties, a polymerization process using the same, and the resulting polymers, wherein the composition comprises the admixture or reaction product resulting from combining: (A) a first olefin polymerization procatalyst, (B) a second olefin polymerization procatalyst capable of preparing polymers differing in chemical or physical properties from the polymer prepared by procatalyst (A) under equivalent polymerization conditions, (C) an activator, and (D) a chain shuttling agent.