The present disclosure provides a process. The process includes (i) forming a composition containing a peroxide-modified ethylene-based polymer selected from the group consisting of a peroxide-modified ethylene/a-olefin multi-block copolymer, a peroxide-modified low density polyethylene, and combinations thereof; (ii) contacting the composition with a blowing agent to form a foam composition; and (iii) forming foam beads comprising the foam composition. The present disclosure also provides a foam bead produced by said process.

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 invention relates to a polyolefin-polystyrene multi-block copolymer having a structure comprising a polyolefin block and polystyrene blocks bonded to both ends of the polyolefin block, to an organozinc compound for preparing the same, and a method for preparing the polyolefin-polystyrene multi-block copolymer.

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 invention relates to isoprene and butadiene and/or pentadiene stereoblock copolymers in which the different stereoregular blocks, joined to each other by means of a single junction point, have different structures and thermal properties. The invention also relates to a process for the preparation of the aforesaid copolymers which comprises the formation of stereoblocks in successive steps but in the presence of a single catalytic system obtained from cobalt dichloride, a phosphine and an organic compound of aluminum.

The present disclosure provides a process. The process includes (i) forming a composition containing a peroxide-modified ethylene-based polymer selected from the group consisting of a peroxide-modified ethylene/a-olefin multi-block copolymer, a peroxide-modified low density polyethylene, and combinations thereof; (ii) contacting the composition with a blowing agent to form a foam composition; and (iii) forming foam beads comprising the foam composition. The present disclosure also provides a foam bead produced by said process.

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.

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 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 polyolefin-polystyrene multi-block copolymer having a structure comprising a polyolefin block and polystyrene blocks bonded to both ends of the polyolefin block, to an organozinc compound for preparing the same, and a method for preparing the polyolefin-polystyrene multi-block copolymer.