The present invention provides a 4-methyl-1-pentene/α-olefin copolymer being excellent in lightness, stress absorption, stress relaxation, vibration damping properties, scratch resistance, abrasion resistance, toughness, mechanical properties and flexibility, having no stickiness during molding operation and being excellent in the balance among these properties; a composition comprising the polymer; and uses thereof. The 4-methyl-1-pentene/α-olefin copolymer (A) of the present invention satisfies specific requirements, and comprises 5 to 95 mol % of a structural unit (i) derived from 4-methyl-1-pentene, 5 to 95 mol % of a structural unit (ii) derived from at least one kind of α-olefin selected from α-olefins having 2 to 20 carbon atoms excluding 4-methyl-1-pentene and 0 to 10 mol % of a structural unit (iii) derived from a non-conjugated polyene, provided that the total of the structural units (i), (ii), and (iii) is 100 mol %.

Provide is a polymer that can provide excellent toughness and weather resistance to a rubber composition and a rubber product such as a tire. The multicomponent copolymer contains a conjugated diene unit, a non-conjugated olefin unit and an aromatic vinyl unit, where a proportion of conjugated diene units bonded to a unit other than a conjugated diene unit out of the total conjugated diene units is 50% or more.

Provide is a polymer that can provide excellent toughness and weather resistance to a rubber composition and a rubber product such as a tire. The multicomponent copolymer contains a conjugated diene unit, a non-conjugated olefin unit and an aromatic vinyl unit, where a proportion of conjugated diene units bonded to a unit other than a conjugated diene unit out of the total conjugated diene units is 50% or more.

Disclosed is the preparation of compatibilized thermoplastic vulcanizates with reduced crosslinked rubber dispersion sizes and dispersity. A cross-linkable ethylene-propylene-diene terpolymer with majority propylene (PEDM) is used to compatibilize a plastic and rubber blend of a polypropylene (PP) and an ethylene-propylene-diene terpolymer rubber, where the propylene content is less than 50 wt % (EPDM), in dynamic vulcanization and preparation of PP/EPDM thermoplastic vulcanizates. The resulting PP/EPDM thermoplastic vulcanizates typically exhibit a weight average equivalent dispersion diameter of less than 3 microns and a particle size polydispersity index (PSDI), or weight average over number average dispersion diameter, of less than 5. This reduction in crosslinked rubber dispersion size in a PP/EPDM TPV by using PEDM compatibilizers enhances the toughness of the vulcanizate product by raising both elongation to break and break stress.

A process for the synthesis of an ethylene/butadiene copolymer is provided. The process is continuous and comprises: a. feeding at least one stirred polymerization reactor with a mixture of ethylene, butadiene, hydrocarbon-based solvent and catalytic system allowing the formation of cyclic trans-1,2-cyclohexane units in the polymer chain with a mole ratio of ethylene to the sum of the ethylene and butadiene monomers ranging from 0.5 to 0.99; the concentration of ethylene and butadiene monomers in the polymerization reaction medium being at least 10% by weight relative to the total weight; the operating pressure of the reactor is greater than or equal to the saturated vapour pressure of the polymerization reaction medium; b. recovering the ethylene/butadiene copolymer, this copolymer comprising, statistically distributed, ethylene units, butadiene units and trans-1,2-cyclohexane units, the molar fraction of ethylene units in the copolymer being greater than or equal to 50%.

A process for the synthesis of an ethylene/butadiene copolymer is provided. The process is continuous and comprises: a. feeding at least one stirred polymerization reactor with a mixture of ethylene, butadiene, hydrocarbon-based solvent and catalytic system allowing the formation of cyclic trans-1,2-cyclohexane units in the polymer chain with a mole ratio of ethylene to the sum of the ethylene and butadiene monomers ranging from 0.5 to 0.99; the concentration of ethylene and butadiene monomers in the polymerization reaction medium being at least 10% by weight relative to the total weight; the operating pressure of the reactor is greater than or equal to the saturated vapour pressure of the polymerization reaction medium; b. recovering the ethylene/butadiene copolymer, this copolymer comprising, statistically distributed, ethylene units, butadiene units and trans-1,2-cyclohexane units, the molar fraction of ethylene units in the copolymer being greater than or equal to 50%.

This invention relates to a thermoplastic vulcanizate having excellent elongation comprising an isotactic polypropylene matrix phase in which a cross-linked ethylene-propylene-diene terpolymer (EPDM) is dispersed, the vulcanizate comprising the reaction product of: a) 35 to 55 wt % of an ethylene-propylene-diene terpolymer (EPDM); b) 10 to 40 wt % of isotactic polypropylene (iPP); c) 0.5 to 25 wt % of a propylene-ethylene-diene terpolymer (PEDM) compatibilizer, said compatibilizer having a heat of fusion of less than 2 J/g; and d) 0.015 to 0.03 wt % of curatives;
wherein the percentages of components (a) to (d) are based on the total weight of the mixture.

A polypropylene comprising a xylene soluble fraction of 1.5 wt % by weight of the polymer and soluble fraction or less, wherein the polypropylene has a melt flow rate within a range from 50 g/10 min to 500 g/10 min and a flexural modulus within a range from 1780 MPa to 2200 MPa. The polypropylene is preferably made from contacting propylene with a solid magnesium/titanium catalyst component that has been washed at least once with a solvent having a desirable solubility parameter.

A polypropylene comprising a xylene soluble fraction of 1.5 wt % by weight of the polymer and soluble fraction or less, wherein the polypropylene has a melt flow rate within a range from 50 g/10 min to 500 g/10 min and a flexural modulus within a range from 1780 MPa to 2200 MPa. The polypropylene is preferably made from contacting propylene with a solid magnesium/titanium catalyst component that has been washed at least once with a solvent having a desirable solubility parameter.

Disclosed is the preparation of thermoplastic vulcanizates with reduced crosslinked rubber dispersion sizes and dispersity. The thermoplastic vulcanizates include a polypropylene matrix phase in which cross-linked rubber particles are dispersed. The thermoplastic vulcanizates include the reaction product of a mixture that includes at least 10 wt % of isotactic polypropylene at least 30 wt % of an amorphous propylene-ethylene-diene terpolymer containing at least 60 wt % propylene-derived units and less than or equal to 25 wt % of ethylene-derived units; at least 10 wt % of a diluent and at least 0.015 wt % of at least one curative. The mixture is preferably formed without adding an ethylene-propylene-diene terpolymer.