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 multiblock, cationic-functionalized norbornene copolymer is formed by a process including performing a vinyl addition polymerization in the presence of a metal catalyst of a first norbornene monomer substituted with a first alkyl group and a second norbornene monomer substituted with a second alkyl group by adding a predetermined amount of the first norbornene monomer and a predetermined amount of the second norbornene monomer sequentially to the reaction to form blocks of an intermediate norbornene multiblock copolymer. The second alkyl group includes a substituent which undergoes a reaction with a precursor for a cationic group having a volume less than 0.25 cm.sup.3/mol. The process further includes reacting the precursor for the cationic group with the intermediate norbornene multiblock copolymer to form the multiblock, cationic-functionalized norborene copolymer.

A statistical, cationic-functionalized norbornene copolymer is formed by a process including performing a vinyl addition polymerization in the presence of a metal catalyst of a first norbornene monomer substituted with a first alkyl group and at least a second norbornene monomer substituted with a second alkyl group, to form an intermediate norbornene copolymer. The second alkyl group includes a substituent which undergoes a substitution reaction with a precursor of a cationic group. The process further includes adding the precursor for the cationic group to the intermediate norbornene copolymer to form the cationic functionalized norbornene copolymer. The cationic group has a volume of 0.25 cm.sup.3/mol or greater (for example, a phosphonium group or an imidazolium group).

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.

A block copolymer composition is disclosed herein. In some embodiments, a block copolymer composition has a weight average molecular weight (M.sub.w) of 70,000 g/mol to 120,000 g/mol, a polydispersity index (PDI) of 1.0 to 2.0, a glass transition temperature (T.sub.g) of −55° C. to −30° C., and a melt index (MI), measured at 230° C. and a loading condition of 5 kg, of 0.2 g/10 minutes to 3.0 g/10 minutes. The block copolymer composition has excellent processability.

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.

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 block copolymer composition is disclosed herein. In some embodiments, the block copolymer composition includes a diblock copolymer and a triblock copolymer each including a polyolefin-based block and a polystyrene-based block. The diblock copolymer is present at less than or equal to 19% , based on total weight of the block copolymer composition, the polyolefin-based block includes a repeating unit represented by Formula 1, and the polystyrene-based block includes one or more of Formulas 2 and 3: ##STR00001## wherein R.sub.1 is hydrogen, C3 to C20 alkyl, or C3 to C20 alkyl substituted with silyl, R.sub.2 and R.sub.3 are each independently C6 to C20 aryl, or C6 to C20 aryl substituted with halogen, C1 to C12 alkyl, or C3 to C12 cycloalkyl, n is an integer from 1 to 10,000, and l and m are each independently an integer from 10 to 1,000.