The inventors have discovered a method of comprising formation of water soluble catalyst precursor by combining a Group 8 to Group 11 transition metal containing catalyst and a surfactant. The surfactant is characterized by the presence of a hydrophobic segment and a hydrophilic segment. It is believed that the surfactant replaces the labile ligand on the catalyst precursor structure by simple ligand substitution. The precursor is then contacted with one or more monoethylenically unsaturated monomers under polymerization conditions to form a polymer.

A two steps polymerization process for obtaining a polyolefin composition comprising: a) from 25 wt % to 70 wt % of a propylene homopolymer or a propylene-ethylene copolymer containing from 0.1 wt % to 10 wt % of ethylene derived units; b) from 27 wt % to 70 wt % of a copolymer of ethylene and at least one C.sub.3-C.sub.20 alpha olefins, wherein the ethylene derived units content ranges from 15 wt % to 70 wt %; c) from 3 wt % to 20 wt % of polyethylene homopolymer or an ethylene and at least one C.sub.3-C.sub.20 alpha olefins copolymer; the sum a)+b)+c) being 100, wherein said process comprises: step a) contacting under polymerization conditions propylene, optionally ethylene and the catalyst system in order to obtain component a), step b) contacting under polymerization conditions ethylene and at least one C3-C20 alpha-olefins and the catalyst system in order to obtain components b) and c); wherein the catalyst system comprises a metallocene compound and an iron complex.

The invention relates to a process for producing a polypropylene composition by sequential polymerization said polypropylene composition having low sealing initiation temperature (SIT) and high melting point (Tm), presenting thus a broad sealing window.

The present invention relates to a photocurable composition which includes a cyanoacrylate component, a metallocene component, a photoinitiator and a plasticizer component, reaction products of which show among other things improved flexibility in terms of elongation at break.

Disclosed is a vinyl alcohol-based block copolymer that is a block copolymer composed of a vinyl alcohol-based polymer block (B-b) and a copolymer block (B-c) comprising a vinyl alcohol-based monomer unit and an acrylic acid-based monomer unit, wherein a content (Z) of the acrylic acid-based monomer unit relative to all monomer units is 0.05 to 20.0 mol %, the block copolymer has a saponification degree of 80 to 99.99 mol %, the block copolymer has a number-average molecular weight (Mn.sub.a) of 20,000 to 440,000, the block copolymer has a molecular weight distribution (Mw.sub.a/Mn.sub.a) of 1.05 to 1.95, and a ratio (DP.sub.b/DP.sub.a) of a number-average polymerization degree (DP.sub.b) of the vinyl alcohol-based polymer block (B-b) to the number-average polymerization degree (DP.sub.a) of the block copolymer is 0.010 to 0.999. The copolymer has a fine balance derived from the copolymer block (B-c) of having a superior solubility in water while being unlikely to undergo thickening or gelation due to pH fluctuation, and also has high mechanic strength derived from the vinyl alcohol-based polymer block (B-b).

The present invention relates to a compound represented by the chemical formula 1, a catalyst system for olefin oligomerization comprising the same, and a method for oligomerizign olefins using the same, and the catalyst system for olefin oligomerization according to the present invention has excellent catalytic activity as well as high selectivity for 1-hexene or 1-octene, thereby enabling more efficient preparation of alpha-olefins.

The present disclosure provides a compound, a complex, a preparation method thereof, and a use thereof. The compound is represented by the following structural formula, in which R.sup.1 to R.sup.10 are the same or different and are each independently selected from hydrogen, a hydrocarbon group having a carbon number of C.sub.1 to C.sub.16, a substituted hydrocarbon group, an alkoxy group, an alkylthio group, an alkylamino group, a haloalkylthio group, a halogen-substituted alkoxy group, a halogen-substituted alkylamino group, an aryloxy group, an arylthio group, arylamino group, a diphenylphosphino group, a halogen group, a nitro group, or a nitrile group. The complex of one embodiment of the present disclosure has a high catalytic effect, and can be used to prepare a highly branched, controllable, low molecular weight polymer with a high activity.

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Provided is novel polybutadiene having high isotacticity. The polybutadiene has a triad isotacticity (mm) of 72% or more.

Provided is novel polybutadiene having high isotacticity. The polybutadiene has a triad isotacticity (mm) of 72% or more.

The invention relates to polybutadiene, which contains the monomer units derived from 1,3-butadiene having a vinyl double bond in a proportion of 25 to 75 mole percent, having a trans-double bond in a proportion of 0 to 10 mole percent and a cis-double bond in a proportion of 25 to 75 mole percent, wherein the totality of the monomer units (A), (B) and (C) is supplemented to 100 mole percent, and which is characterized in that it has a number-average mole mass of 1,000 to 3,000 g/mole. The invention further relates to a method for producing polybutadienes, the use of the polybutadiene according to the invention and compositions containing polybutadiene according to the invention.