A nano platelet gibbsite treated with compound of formula (OR.sup.a).sub.3Si—R.sup.b or of formula R.sup.c—COOH wherein R.sup.a equal to or different from each other is a C.sub.1-C.sub.10 alkyl radical; R.sup.b is a C.sub.5-C.sub.30 hydrocarbon radical and R.sup.c is a C.sub.5-C.sub.30 hydrocarbon radical is used as a catalyst support.

The present invention concerns a process for the preparation of a copolymer comprising the steps of copolymerizing under suitable reaction conditions at least one first type of olefin monomer and at least one second type of functionalized olefin monomer using a catalyst system to obtain a polyolefin main chain having one or multiple functionalized short chain branches, the catalyst system comprising: i) a single-site catalyst or catalyst precursor comprising a metal selected from Ti3+ or Cr3+; ii) a co-catalyst; iii) optionally a scavenger.

An improved catalyst for cyclic olefin polymerization. The catalyst includes a transition metal carbene having the following structure: M.sup.v(OR’).sub.c*mX(.sub.v-c*m-2)=C(R*).sub.2 wherein M.sup.v is a Group 5 transition metal having a valence (v) of 5 or a Group 6 transition metal having a valence (v) of 5 or 6; each R′ is independently a monovalent organic moiety comprising from 8 to 40 atoms selected from Groups 14-17; c is an integer from 1 to 3; m is ⅓, ½, 1, 3/2, 2, 3, or 4 and c*m ≤ v-2; X is a halogen; and each R* is independently H or a C.sub.1 to C.sub.7 alkyl. The catalyst is particularly useful for ring-opening metathesis polymerization (ROMP).

A nano platelet gibbsite treated with compound of formula (OR.sup.a).sub.3Si—R or of formula R.sup.c—COOH wherein R.sup.a equal to or different from each other is a C.sub.1-C.sub.10 alkyl radical; R.sup.b is a C.sub.5-C.sub.30 hydrocarbon radical and R.sup.c is a C.sub.5-C.sub.30 hydrocarbon radical is used as a catalyst support.

Methods for preparing supported chromium catalysts containing a chromium (III) compound and an activator-support are disclosed. These supported chromium catalysts can be used in catalyst compositions for the polymerization of olefins to produce polymers having low levels of long chain branching, and with greater sensitivity to the presence of hydrogen during polymerization.

Methods for preparing supported chromium catalysts containing a chromium (III) compound and an activator-support are disclosed. These supported chromium catalysts can be used in catalyst compositions for the polymerization of olefins to produce polymers having low levels of long chain branching, and with greater sensitivity to the presence of hydrogen during polymerization.

Methods for preparing supported chromium catalysts containing a chromium (III) compound and an activator-support are disclosed. These supported chromium catalysts can be used in catalyst compositions for the polymerization of olefins to produce polymers having low levels of long chain branching, and with greater sensitivity to the presence of hydrogen during polymerization.

The present invention concerns a process for the preparation of a copolymer comprising the steps of copolymerizing under suitable reaction conditions at least one first type of olefin monomer and at least one second type of functionalized olefin monomer using a catalyst system to obtain a polyolefin main chain having one or multiple functionalized short chain branches, the catalyst system comprising: i) a single-site catalyst or catalyst precursor comprising a metal selected from Ti3+ or Cr3+; ii) a co-catalyst; iii) optionally a scavenger.

This invention relates to a catalyst system comprising a half sandwich chromocene compound featuring a tethered P-donor, with an activator and optional supportation on silica which produces ethylene homopolymer or copolymer.

This invention relates to a catalyst system comprising a half sandwich chromocene compound featuring a tethered P-donor, with an activator and optional supportation on silica which produces ethylene homopolymer or copolymer.