The present disclosure relates to a process for synthesizing multi- or dual-headed compositions having the formula R.sup.1M.sup.A[R.sup.2M.sup.A-].sub.NR.sup.1 by employing a sterically hindered compound and an organometallic compound in the presence of a transition metal catalyst. The present disclosure further relates to use of the compositions, as well as the process to make the same, in olefin polymerization.

The present disclosure relates to a solid curable transparent rubber composition containing a styrenic block copolymer having 2 or more poly(vinyl aromatic) blocks, a curing agent and additives. Once cured, the solid curable transparent rubber composition has a haze of less than 30% and a total light transmission of more than 80%. The disclosure further relates to a cured transparent rubber composition made thereof, and a manufacturing process for the cured composition. The present disclosure also relates to an article including the rubber composition, in particular for tubes, medical stoppers, catheters, dental dams and other medical applications and artificial nipples.

A method for preparing a functionalized polymer, the method comprising the steps of: (i) polymerizing monomer to form a reactive polymer, and (ii) reacting the reactive polymer with a protected oxime compound containing a cyano group.

A method for preparing a functionalized polymer, the method comprising the steps of: (i) polymerizing monomer to form a reactive polymer, and (ii) reacting the reactive polymer with a protected oxime compound containing a cyano group.

The invention relates to an efficient polymerization process and its use to produce novel copolymers with a specific micro structure. In particular, the invention relates to butyl rubbers with novel micro structure, preferably those obtainable by copolymerization of monomer mixtures comprising isobutylene and isoprene in diluents comprising 2,3,3,3 -tetrafluoro-1-propene. In a further aspect the invention relates to halogenated copolymers obtainable from such novel copolymers by halogenation.

This invention relates to a process to using dimers of a group 3 metal (typically scandium) catalyst compound to produce ethylene polymers, such as ethylene-alpha-olefin copolymers and ethylene-conjugated diene copolymers.

The invention relates to neodymium-catalyzed polybutadienes (NdBR) comprising >95 wt % of cis-1,4 units and <1 wt % of 1,2-vinyl content, based on the neodymium-catalyzed polybutadiene, wherein the NdBR evinces a molar mass breakdown of not less than 25%.

The present invention relates to a polymerization initiator represented by Formula 1, a modified conjugated diene-based polymer, methods for preparing them, a rubber composition comprising the modified conjugated diene-based polymer, and a tire prepared from the rubber composition.

##STR00001##

(In Formula 1, the definition of each substituent is the same as defined in the description.)

The present invention relates to a polymerization initiator represented by Formula 1, a modified conjugated diene-based polymer, methods for preparing them, a rubber composition comprising the modified conjugated diene-based polymer, and a tire prepared from the rubber composition.

##STR00001##

(In Formula 1, the definition of each substituent is the same as defined in the description.)

This invention relates to a process to using dimers of a group 3 metal (typically scandium) catalyst compound to produce ethylene polymers, such as ethylene-alpha-olefin copolymers and ethylene-conjugated diene copolymers.