A copolymer of ethylene and of myrcene, in which the ethylene units represent between 50 mol % and 95 mol % of the ethylene units and of the myrcene units, and the myrcene units of 1,2 and 3,4 configuration represent more than 50 mol % of the myrcene units, is provided. Such a copolymer exhibits an improved compromise between the degree of crystallinity and the stiffness. It therefore makes it possible to widen the field of application of ethylene-rich diene copolymers in rubber compositions, and also to increase the production capacity of a unit for the synthesis of ethylene-rich diene polymers.

A copolymer of ethylene and of myrcene, in which the ethylene units represent between 50 mol % and 95 mol % of the ethylene units and of the myrcene units, and the myrcene units of 1,2 and 3,4 configuration represent more than 50 mol % of the myrcene units, is provided. Such a copolymer exhibits an improved compromise between the degree of crystallinity and the stiffness. It therefore makes it possible to widen the field of application of ethylene-rich diene copolymers in rubber compositions, and also to increase the production capacity of a unit for the synthesis of ethylene-rich diene polymers.

An elastomeric composition suitable for use in layered articles like hoses and belts may include: 5 phr to 80 phr of a PEDM terpolymer comprising 55 wt % to 95 wt % propylene, 2.5 wt % to 40 wt % α-olefin, and 0.05 wt % to 25 wt % diene and having Mooney viscosity (ML(1+4)) of 5 MU to 90 MU; 20 phr to 95 phr of an ethylene-based copolymer selected from: (a) a crystalline ethylene-based copolymer comprising 60 wt % to 95 wt % ethylene, 0 wt % to 10 wt % of one or more dienes, and 5 wt % to 40 wt % C3 to C12 α-olefin, (b) an amorphous ethylene-based comprising 40 wt % to 59 wt % ethylene, 0 wt % to 10 wt % of one or more dienes, and 40 wt % to 60 wt % C3 to C12 α-olefin, and (c) a combination of (a) and (b); and 10 phr to 200 phr of a process oil.

An elastomeric composition suitable for use in layered articles like hoses and belts may include: 5 phr to 80 phr of a PEDM terpolymer comprising 55 wt % to 95 wt % propylene, 2.5 wt % to 40 wt % α-olefin, and 0.05 wt % to 25 wt % diene and having Mooney viscosity (ML(1+4)) of 5 MU to 90 MU; 20 phr to 95 phr of an ethylene-based copolymer selected from: (a) a crystalline ethylene-based copolymer comprising 60 wt % to 95 wt % ethylene, 0 wt % to 10 wt % of one or more dienes, and 5 wt % to 40 wt % C3 to C12 α-olefin, (b) an amorphous ethylene-based comprising 40 wt % to 59 wt % ethylene, 0 wt % to 10 wt % of one or more dienes, and 40 wt % to 60 wt % C3 to C12 α-olefin, and (c) a combination of (a) and (b); and 10 phr to 200 phr of a process oil.

A copolymer of ethylene and of a 1,3-diene of formula CH.sub.2═CR—CH═CH.sub.2 is provided. The ethylene units represent between 50 mol % and 95 mol % of the ethylene units and of the units of the 1,3-diene, and the units of the 1,3-diene of 1,2 and 3,4 configuration represent more than 50 mol % of the units of the 1,3-diene. The symbol R represents a hydrocarbon chain having from 3 to 20 carbon atoms. Such a copolymer exhibits an improved compromise between the degree of crystallinity and the stiffness and makes it possible to widen the field of application of ethylene-rich diene copolymers in rubber compositions.

A copolymer of ethylene and of a 1,3-diene of formula CH.sub.2═CR—CH═CH.sub.2 is provided. The ethylene units represent between 50 mol % and 95 mol % of the ethylene units and of the units of the 1,3-diene, and the units of the 1,3-diene of 1,2 and 3,4 configuration represent more than 50 mol % of the units of the 1,3-diene. The symbol R represents a hydrocarbon chain having from 3 to 20 carbon atoms. Such a copolymer exhibits an improved compromise between the degree of crystallinity and the stiffness and makes it possible to widen the field of application of ethylene-rich diene copolymers in rubber compositions.

Provided is a rubber composition containing an ethylene-α-olefin-nonconjugated polyene copolymer rubber and a phenolic antioxidant, in which a content of an ethylene unit in the ethylene-α-olefin-nonconjugated polyene copolymer rubber is from 71% to 99% by mass with respect to a total amount of the ethylene unit, an α-olefin unit, and a nonconjugated polyene unit, a proportion of a cyclohexane insoluble component in the ethylene-α-olefin-nonconjugated polyene copolymer rubber at 25° C. is from 0.2% to 50% by mass with respect to a mass of the ethylene-α-olefin-nonconjugated polyene copolymer rubber, and a content of the phenolic antioxidant is from 0.01 to 0.35 part by mass with respect to 100 parts by mass of a content of the ethylene-α-olefin-nonconjugated polyene copolymer rubber.

Provided is a rubber composition that can achieve excellent breaking resistance while having high operability. A rubber composition comprises: a rubber component containing a multicomponent copolymer that contains a conjugated diene unit, a non-conjugated olefin unit, and an aromatic vinyl unit; and at least one selected from an ethylene-α olefin copolymer and an ethylene-aromatic vinyl copolymer each having a number-average molecular weight of 500 to 30,000.

Provided is a rubber composition that can achieve excellent breaking resistance while having high operability. A rubber composition comprises: a rubber component containing a multicomponent copolymer that contains a conjugated diene unit, a non-conjugated olefin unit, and an aromatic vinyl unit; and at least one selected from an ethylene-α olefin copolymer and an ethylene-aromatic vinyl copolymer each having a number-average molecular weight of 500 to 30,000.

The present inventions concerns a plant producing an in-line blended polymer comprising a first polymerisation reactor and a second polymerisation reactor, the first and second polymerisation reactors having different internal volumes, and a method for producing an in-line blended polymer.