The present invention provides a modified butadiene-based polymer capable of enhancing dispersability of an inorganic filler when used in a rubber composition, and enhancing viscoelasticity, a tensile property and processibility of the rubber composition in a balanced way from an interaction with the inorganic filler, and a modifier useful for preparing the same.

The present invention relates to a modified styrene-butadiene copolymer with a high modification ratio, including a functional group derived from a modifier represented by Formula 1, a preparation method thereof, a rubber composition including the same, and a tire manufactured from the rubber composition.

The present invention relates to a modified styrene-butadiene copolymer with a high modification ratio, including a functional group derived from a modifier represented by Formula 1, a preparation method thereof, a rubber composition including the same, and a tire manufactured from the rubber composition.

According to an embodiment of the present invention, there is provided a method of preparing a rubber composition, which includes (a) synthesizing a living polymer by solution polymerization of a monomer mixture including a conjugated diene-based monomer in the presence of a first catalyst; (b) reacting some ends of the living polymer with a coupling agent; (c) reacting the remaining ends of the living polymer with an organotin halide compound to prepare an end-modified conjugated diene-based polymer solution; and (d) adding a second catalyst and a conjugated diene-based monomer to the end-modified conjugated diene-based polymer solution to induce solution polymerization.

An ethylenically unsaturated polymer includes at a terminus the radical of an allylic compound that includes a functional group free of active hydrogen atoms that is bonded to the allylic C atom through a S, P, Si or Sn atom and a vinyl aromatic compound. The polymer can be used as a component of a variety of elastomeric compounds used in the production of vulcanizates.

The present invention is to provide a diene polymer that exhibits excellent low rolling resistance when used in a tire, a method for producing the diene polymer, and a rubber composition containing the diene polymer. The diene polymer of an embodiment of the present invention is produced by polymerizing a monomer containing at least a diene monomer by using an initiator prepared from an organolithium compound, an alkyl aluminum, and a metal alcoholate, and then terminating the polymerization by using an electrophile selected from the group consisting of titanium halides, tin halides, cyclic silazanes, alkoxysilanes, epoxides, amines, ketones, and compounds represented by Formula (N) below.

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Provided is an ethylene-vinyl alcohol copolymer with an ethylene unit content of 15 to 60 mol % and a saponification degree of 85 mol % or more.

A method for tailoring mechanical properties of a photopolymer includes providing an active monomer feedstock, adding a sulfur-free chain transfer agent (CTA) to the active monomer feedstock to form a mixture, and curing the mixture under predetermined conditions. The sulfur-free CTA includes a Cobalt(II) complex or a Cobalt(III) complex, the mechanical properties include glass transition temperature, crosslinking density, and/or conversion rate, and a concentration of the sulfur-free CTA is less than 30% of the mixture. The predetermined conditions include intensity, wavelength, and application time of energy from a light source, a cure temperature, and/or the concentration of the sulfur-free CTA in the mixture. The method may further include adding a diluent to the mixture to modify a viscosity of the active monomer feedstock. The diluent may include one of a reactive diluent and a non-reactive diluent, such as methyl methacrylate (MMA) and methacrylate (MA).

A synthetic polyisoprene latex containing synthetic polyisoprene, wherein the synthetic polyisoprene constituting the synthetic polyisoprene latex includes a low-molecular weight synthetic isoprene chain having a molecular weight of less than 1,000,000 at a content rate of 10 to 70% by weight and a high-molecular weight synthetic isoprene chain having a molecular weight of 1,000,000 or more at a content rate of 30 to 90% by weight. Also, a method for producing the synthetic polyisoprene latex, wherein the synthetic polyisoprene containing the low-molecular weight synthetic isoprene chain and the high-molecular weight synthetic isoprene chain is obtained by polymerizing a monomer containing isoprene in an organic solvent by use of an organic alkali metal catalyst.

A method for producing a polymer containing metal atoms or halogen atoms at the terminals thereof with excellent efficiency while minimizing or eliminating side reactions or the like is provided. The method can also freely control molecular weight characteristics of the polymer.